ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Zea mays  (193)
  • Springer  (193)
  • 2020-2024
  • 1990-1994  (193)
Collection
Years
Year
  • 101
    ISSN: 1615-6102
    Keywords: Cold treatment ; Cytoskeleton ; Microtubules ; Roots ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Microtubules (MTs) in cells of various tissues at different distances from the apex of the maize root exhibited different sensitivities to cold (5 °C), as judged by MT reorientation and tendency to depolymerization. Their responses seem to be related to their initial intracellular arrangements. Generally, MTs in cells which were ceasing elongation were the least sensitive during the early stages (6–24 h) of cold treatment, but during the later stages (5–7 d) MTs in most of these cells eventually depolymerized. Pericycle cells showed a unique cold response. Here the MTs were conspicuously cold-labile and quickly depolymerized near the root-tip. However, after 1 d many pericycle cells in more proximal regions had repolymerized their MTs as dense, randomly organized arrays. These persisted for the remainder of the cold treatment. A similar resistance to longterm chilling, by means of MT repolymerization, was found in cells of the root cap, quiescent centre and cells of the distal part of the former meristem. MT repolymerization in the cold may enable the apex to resume growth when more favourable (warmer) conditions return.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 102
    ISSN: 1615-6102
    Keywords: Auxin ; Meristem (root) ; Quiescent center ; Root cap ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Using roots of maize, we tested the hypothesis that the origin and maintenance of the quiescent center (QC) are a consequence of polar auxin supply. Exposing roots to the polar auxin transport inhibitor 2,3,5-triiodobenzoic acid (TIBA), or to low temperature (4 °C, with subsequent return to 24 °C), enhances mitotic frequency within the QC. In both treatments, the QC most typically is activated at its distal face, and the protoderm/dermatogen undergoes several periclinal divisions. As a result, the root body penetrates and ruptures the root cap junction and the characteristic “closed” apical organization changes to “open”. A QC persists during these changes in apical organization, but it is diminished in size. The data from the TIBA-treated roots suggest a role for auxin in the origin and maintenance of the QC, and further, that alterations in QC dimensions are a consequence of polar auxin supply. We hypothesize that the root cap, and specifically the root cap initials, are important in regulating polar auxin movements towards the root apex, and hence are important in determining the status of the QC.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 103
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 234 (1992), S. 353-360 
    ISSN: 1617-4623
    Keywords: Zea mays ; Somatic instability ; Bronze-2 ; Genomic shock ; Pollen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary After epigenetic loss of Mutator activity, the family of Mu elements in Zea mays becomes immobile and highly methylated; in addition, Mu9, the presumptive autonomous regulatory element, is transcriptionally silent and its copy number decreases in successive crosses to non-Mutator lines. Spontaneous reactivation, scored as restoration of somatic instability of potentially mutable alleles of Bronze-2, of such cryptic Mutator lines is rare, occurring with a frequency of about 10−4. Irradiation of pollen with 254 nm ultraviolet light increases reactivation rate in the progeny kernels by up to 40-fold. Accompanying reactivation, the copy number of Mu9 elements increased, two-fold in one line and 20 to 40-fold in a second line. Reactivation may involve direct DNA damage or immediate physiological stress in the treated pollen.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 104
    ISSN: 1617-4623
    Keywords: Zea mays ; Chloroplasts ; rpo genes ; RNA polymerase ; Heptameric repeat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The genes (rpo B/C1/C2) coding for the β, β′, β″ subnits of maize (Zea mays) chloroplast RNA polymerase have been located on the plastome and their nucleotide sequences established. The operon is part of a large inversion with respect to the tobacco and spinach chloroplast genomes and is flanked by the genes trnC and rps2. Notable features of the nucleotide sequence are the loss of an intron in rpoC1, and an insertion of approximately 450 by in rpOC2 compared to the dicotyledons tobacco, spinach and liver-wort. The derived amino acid sequence of this additional monocotyledon specific sequence is characterized by acidic heptameric repeat units containing stretches of glutamic acid, tyrosines and leucines with regular spacing. Other structural motifs, such as a nucleotide binding domain in the β subunit and a zinc finger in the β′ subunit, are compared at the amino acid level throughout the RNA polymerase subunits with the enzymes from other organisms in order to identify functionally important conserved regions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 105
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 238 (1993), S. 201-208 
    ISSN: 1617-4623
    Keywords: TNPA protein ; DNA binding ; Transposition ; Zea mays ; Transgenic plants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The En/Spm-encoded TNPA protein binds to 12-bp DNA sequence motifs that are present in the sub-termini of the transposable element. DNA binding of TNPA to monomeric and dimeric forms of the binding motif was analyzed by gel retardation and cross-linking studies. A DNA binding domain at the N-terminal and a dimerization domain at the C-terminal portion of TNPA were localized using deletion derivatives of TNPA. These domains are novel since no apparent homology has been found in the data bases. The stoichiometry of the TNPA-DNA complexes was analyzed. A special complex is formed with a tail-to-tail dimeric DNA binding motif, most probably involving two DNA-bound TNPA molecules that interact via their dimerization domains. In redox reactions the requirement for one or two disulfide bonds for DNA binding of TNPA was shown. The implications of these findings for the excision mechanism of En/Spm are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 106
    ISSN: 1617-4623
    Keywords: Flavonoids ; Light regulation ; Sn locus ; Tissue-specificity ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The Sn locus of maize is functionally similar to the R and B loci, in that Sn differentially controls the tissue-specific deposition of anthocyanin pigments in certain seedling and plant cells. We show that Sn shows molecular similarity to the R gene and have used R DNA probes to characterize several Sn alleles. Northern analysis demonstrates that all Sn alleles encode a 2.5 kb transcript, which is expressed in a tissue-specific fashion consistent with the distribution of anthocyanins. Expression of the Sn gene is light-regulated. However, the Sn: bol3 allele allows Sn mRNA transcription to occur in the dark, leading to pigmentation in dark-grown seedlings and cob integuments. We report the isolation of genomic and cDNA clones of the light-independent Sn: bol3 allele. Using Sn cDNA as a probe, the spatial and temporal expression of Sn has been examined. The cell-specific localization of Sn mRNA has been confirmed by in situ hybridization using labelled antisense RNA probes. According to its proposed regulatory role, expression of Sn precedes and, in turn, causes a coordinate and tissue-specific accumulation of mRNA of structural genes for pigment synthesis and deposition, such as A1 and C2. The functional and structural relationship between R, B, Lc and Sn is discussed in terms of an evolutionary derivation from a single ancestral gene which gave rise this diverse gene family by successive duplication events.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 107
    ISSN: 1617-4623
    Keywords: Zea mays ; Transposable elements ; Opaque-2 ; Waxy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The two components of theBg-rbg transposable element system of maize have been cloned. TheBg element, isolated from the mutable allelewx-m32 :: Bg is inserted in the intron of theWaxy (Wx) gene between exons 12 and 13. The length of the element is of 4869 bp.Bg has 5 by terminal inverted repeats, and generates upon insertion an 8 by direct duplication of the target sequence. Both ends of theBg element contain a 76 by direct repeat adjacent to the terminal inverted repeats. The hexamer motif TATCGkC G is here repeated several times in direct or inverse orientation. Therbg element was isolated from the mutable alleleo2m(r) where it is located in the promoter region of theOpaque-2 (O2) gene.rbg is approximately 4.5 kb in length, has terminal inverted repeats identical to those of theBg element, and is also flanked by an 8 by direct duplication at the target site. LikeBg, rbg carries the 76 by direct repeats. Restriction enzyme analysis reveals that, compared toBg, the receptor element is distinguishable by small deletion and insertion events. Sequence data indicate that not more than 75% homology exists at the DNA level between therbg element and the autonomousBg element.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 108
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 242 (1994), S. 1-8 
    ISSN: 1617-4623
    Keywords: Zea mays ; Flavonoid biosynthesis ; P gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We report here the first cloning of a chalcone flavonone isomerase gene (CHI) from maize. Northern blot experiments indicate that the maize CHI gene (ZmCHI1) is regulated in the pericarp by the P gene, a myb homologue. The ZmCHI1 gene encodes a 24.3 kDa product 55% and 58% identical to CHI-A and CHI-B from Petunia, respectively. This maize CHI gene has four exons and an intron-exon structure identical to the CHI-B gene of Petunia hybrida. RFLP mapping data indicate that some inbred lines contain two additional CHI-homologous sequences, suggesting an organization more complex than that found in Petunia or bean. The possibility that the additional CHI-homologous sequences are responsible for the lack of CHI mutants in maize will be discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 109
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 237 (1993), S. 105-112 
    ISSN: 1617-4623
    Keywords: Zea mays ; Transposable element ; En/Spm ; Mediator ; Irma element
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Two different factors control the mutability of an unstable allele (c2-m8810581) of the C2 gene of maize. Both an autonomous En/Spm element and an unrelated independent factor, named Mediator, are coordinately required for the excision of the insert in c2-m881058Y. According to genetic analysis, Mediator does not have the suppressor (S) function or mutator (M) function of En/Spm. Mediator has no effect on the timing or frequency of excision of Enl, En-low, or various I/dSpm elements. Hence, Mediator only mediates a specific interaction between En and the insert at c2m881058Y. Molecular analysis of c2-m881058Y has revealed a 3.3 kb, complex, En-related receptor element inserted into the second exon of the C2 gene. The ends of this element are homologous to the ends of En/Spm, but an internal l.7 kb region shows no En/Spm homology. A great degree (11–14%) of nucleotide changes, relative to Enl, occur within and between the 12 bp TNPA binding motifs. Alterations of these critical cis-determinants may account for the need for a “helper” factor for excision. This element is named Irma, for Inhibitor that requires Mediator also, and represents a unique, low copy number class of receptor element.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 110
    ISSN: 1617-4623
    Keywords: Lysine biosynthesis ; Feedback regulation ; Zea mays ; Genetic complementation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Dihydrodipicolinate synthase (DHPS; EC 4.2.1.52) is the first committed enzyme in the lysine branch of the aspartate-derived amino acid biosynthesis pathway and is common to bacteria and plants. Due to feedback inhibition by lysine, DHPS serves in a regulatory role for this pathway in plant metabolism. To elucidate the molecular genetic characteristics of DHPS, we isolated a putative full-length cDNA clone for maize DHPS by direct genetic selection in an Escherichia coli dapA −auxotroph. The maize DHPS activity expressed in the complemented E. coli auxotroph showed the lysine inhibition characteristics of purified maize DHPS, indicating that the cDNA encoded sequences for both the catalytic function and regulatory properties of the enzyme. The N-terminal amino acid sequence of purified maize DHPS was determined by direct sequencing and showed homology to a sequence within the cDNA, indicating that the clone contained the entire coding region for a mature polypeptide of 326 amino acids plus a 54 amino acid transit peptide sequence. The molecular weight of 35854, predicted from the deduced amino acid sequence, was similar to the 38 000 Mr determined by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) for the purified enzyme from maize. DHPS mRNAs complementary to the cDNA were detected in RNA isolated from developing maize endosperm and embryo tissues. Southern blots indicated the presence of more than one genomic sequence homologous to DHPS per haploid maize genome.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 111
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 229 (1991), S. 161-174 
    ISSN: 1617-4623
    Keywords: Zea mays ; transposable element ; Uq activation ; Uq cluster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Allelism tests between the standard Uq element (Uq1) and five newly activated germinal Uq elements (Uq2, Uq3, UQ4, Uq5, and Uq6) demonstrate that these new Uq elements are independent of Uq1. Gametes that either contain one Uq or various combinations of two different and phenotypically distinguishable Uq elements, have been constructed either with or without the a-ruq reporter allele. Genetic analyses of the progenies of the gametes (using the standard a-ruq tested line as the other parent) have indicated that (i) each Uq element, when present alone, has the capacity to express full activity except when a secondary transposition or loss of activity has occurred; (ii) all five new Uq elements are independent of Uq1 with respect to transposition activity; and (iii) these newly originated Uqs are clustered on one linkage group. Uq2 is allelic to Uq4, and Uq3 is allelic to Uq5, whereas Uq6 is linked to both allelic pairs. A putative linkage map of these Uq elements is presented. In reciprocal crosses there is a striking difference in phenotypic segregation of Uq; when transmitted via the male parent Uq loses full expression capacity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 112
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 233 (1992), S. 379-387 
    ISSN: 1617-4623
    Keywords: Bz2 gene ; Transcriptional regulation ; Anthocyanin pathway ; Transient assay ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The putative maize transcription factor genes R and C1 are required for expression of reporter genes with promoters from the Bz1 and A1 genes, which encode enzymes required for anthocyanin biosynthesis in maize. Bz2 is another anthocyanin biosynthetic gene; we show that expression of a reporter gene from the Bz2 promoter also requires R and C1 when the fusion construct is introduced into maize kernels by particle gun bombardment. When electroporated into maize protoplasts from a suspension cell line not synthesizing anthocyanins, reporter genes with Bz2, Bz1, and A1 promoters are expressed only when both R and C1 expression plasmids are co-electroporated. Electroporation of R and C1 expression plasmids also induces the endogenous genes required for anthocyanin synthesis, resulting in pink protoplasts within 24 h. RNase protection analysis demonstrates that accumulation of mRNA from the endogenous Bzl and Bz2 genes absolutely requires introduced R and C1. In time-course experiments there is a delay of 3–6 h before the Bz2 promoter is activated, supporting the proposed role for R- and C1-encoded proteins in transcriptional control. An excess of R relative to C1 suppresses expression of A1, Bz1, and Bz2 promoters, suggesting an interaction between the R and C1 proteins.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 113
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 233 (1992), S. 388-394 
    ISSN: 1617-4623
    Keywords: Viral vector ; Transposable element ; Zea mays ; Agroinfection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have previously shown that the maize transposable element Ds1 introduced into maize plants by agroinfection can be excised from the genome of geminivirus maize streak virus (MSV). Excision depended strictly on the presence of an active Ac element in the plants. In this study, the excision products or “footprints” left in the MSV genome after Ds1 excision were extensively characterized and the effects of flanking sequences on Ds1 excision were analysed. Most types of footprints obtained were comparable to those described for Ds1 excision in the maize genome, and could be explained by the models proposed for excision of plant transposable elements. In two revertants, however, some terminal sequences of the Ds1 element were found to have been left behind at the excision site. The finding of this novel type of Ds1 footprint indicated that gene conversion events occurred during and/or after Ds1 excision from the MSV genome. A partial deletion of one copy of the 8 by duplications flanking the Ds1 element had no effect on the frequency or on the types of footprints of Ds1 excision from the MSV genome. Thus, the duplicated 8 by sequences flanking the transposable element are not involved in Ds1 excision. These results, as well as a statistical analysis of the modifications of the bases flanking the Ds1 element after excision, are discussed in terms of excision models.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 114
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 231 (1992), S. 369-374 
    ISSN: 1617-4623
    Keywords: Zea mays ; Transcription ; Transformation ; Endosperm ; Tissue culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A 43 by fragment containing the — 300 region upstream control element common to the endosperm expressed zein genes of Zea mays L. has been analyzed by in vivo and in vitro techniques. Transient transformation studies with protoplasts from a maize endosperm culture indicate that the element positively affects CaMV 35S promoter-driven gene expression, and that this effect is both orientation- and position-dependent. Band-shift and Southwestern blotting experiments demonstrate that the element is specifically bound by different sets of DNA-binding proteins from seedling and endosperm nuclei. A 2 by substitution within the most conserved region of the element both reduces the stimulatory effect on transcription and alters the binding of nuclear proteins from both tissues.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 115
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 221 (1990), S. 164-170 
    ISSN: 1617-4623
    Keywords: Zea mays ; Zein ; P2 promoter ; Transcription factors ; HMG protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A 216 by promoter fragment of the 19 kDa protein zein gene pMS1, containing the CCAAT and TATA boxes, was analysed by a variety of techniques for in vitro interactions with nuclear proteins from endosperm tissue. HMG proteins were found to form stable complexes with these A/T-rich promoter sequences and several specific DNA-binding proteins appear to be involved in the formation of DNA-protein complexes with this fragment. A 29 bp region spanning the two CCAAT boxes was protected from DNase I digestion in footprinting experiments.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 116
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 221 (1990), S. 475-485 
    ISSN: 1617-4623
    Keywords: Zea mays ; bronze ; Transposable elements ; Ds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The regulatory mutation bronze mutable 4 Derivative 6856 (bz-m4 D6856) contains a complex 6.7 kb Dissociation (Ds) element tagged with a duplication of low copy bz 3′ flanking sequences (Klein et al. 1988). This creates a unique opportunity to study the transposition of a single member of the repetitive family of Ds elements. Eighteen full purple revertants (Bz′ alleles) of bz-m4 were characterized enzymatically and by genomic mapping. For 17 of the Bz′ alleles, reversion to a wild-type phenotype was caused by excision of the 6.7 kb Ds transposon. Nine of these Bz′ alleles retained the transposon somewhere in their genome. In this study we show that like Ac (Schwartz 1989; Dooner and Belachew 1989), the 6.7 kb Ds element can transpose within a short physical distance, both proximal and distal to its original position. Additional bz sequences have been mapped immediately distal to the mutant locus in bz-m4 D6856; genetic evidence suggests these are flanked by two additional Ds elements. The remaining Bz′ revertant, Bz′ :107, arose from excision of a more complex 13 kb Ds element.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 117
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 233 (1992), S. 269-277 
    ISSN: 1617-4623
    Keywords: Zea mays ; Bz2 locus ; Natural antisense transcripts ; Transposable elements ; Gene family
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Analysis of the transcription pattern of theBz2 locus revealed that overlapping transcripts are derived from opposite DNA strands. The most abundant transcript (sense transcript) has an open reading frame coding for a protein of 241 amino acids, whilst in the antisense orientation no open reading frame has been detected; the antisense transcripts are detected only in those tissues that show high levels of sense transcript. Particle gun experiments indicate that the sense transcript is sufficient to provide theBz2 function. The promoter driving the sense transcript contains the elements usually found in front of eukaryotic genes. In addition an element with similarity to theC1 andR binding sites identified in theBz1 promoter is found. Further upstream in the promoter region a transposon-like insertion has been identified. This element has features similar to members of theAc/Ds transposable element family. The putativeBz2 protein shows similarity to various other plant proteins and to anEscherichia coli protein. All related proteins have in common the fact that they are involved in stress responses.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 118
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 223 (1990), S. 457-464 
    ISSN: 1617-4623
    Keywords: Cytoplasmic male sterility ; Zea mays ; Mitochondrial DNA replication ; Nucleocytoplasmic interactions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A WF9 strain of maize with the RD subtype of the S male-sterile cytoplasm (CMS-S) was converted to the inbred M825 nuclear background by recurrent backcrossing. The organization of the mitochondrial genomes of the F1 and succeeding backcross progenies was analyzed and compared with the progenitor RD-WF9 using probes derived from the S1 and S2 mitochondrial episomes, and probes containing the genes for cytochrome c oxidase subunit I (coxI), cytochrome c oxidase subunit II (coxII) and apocytochrome b (cob). Changes in mitochondrial DNA (mtDNA) organization were observed for S1-, S2-, and coxI-homologous sequences that involve loss of homologous restriction enzyme fragments present in the RD-WF9 progenitor. With the coxI probe, the loss of certain fragments was accompanied by the appearance of a fragment not detectable in the progenitor. The changes observed indicate the effect of the nuclear genome on the differential replication of specific mitochondrial subgenomic entities.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 119
    ISSN: 1617-4623
    Keywords: GUS transient expression ; Mobile DNA ; Zea mays ; Petunia hybrida ; Cotransfection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The excision of a Ds-like transposable element (AcΔ) is mediated in trans by the transposable element Ac or its derivatives in Petunia protoplasts cotransfected with two plasmid DNAs. Excision restores the activity of the β-glucuronidase (GUS) gene that is otherwise shut off by the presence of AcΔ in its leader sequence. A transient expression assay (histochemical test) is used to detect the β-glucuronidase activity at the protoplast level. The number of blue-stained protoplasts is a measure of the excision frequency. With AcΔ alone a near-zero background of GUS activity is detected, which is weakly enhanced by the presence, in trans, of either the wild-type Ac or the coding region (ORFa) transcribed from the 2′ promoter of Agrobacterium tumefaciens TR-DNA. A strong enhancement is observed when a truncated Ac coding region, also under the control of the 2′ promoter, is supplied in trans. The truncated version has ATG10 at codon 103 in frame with ORFa and is preceded by 7 out-of-frame ATGs. The assay is quick and well suited for detection of excision frequencies above the value obtained with the wild-type Ac. The presence of empty donor sites following excision can be demonstrated by PCR amplification and direct sequencing of the appropriate DNA fragment.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 120
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 225 (1991), S. 81-93 
    ISSN: 1617-4623
    Keywords: Enhancement ; Intron ; Splicing ; Transient assay ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The inclusion of the alcohol dehydrogenase 1-S (Adh1-S) intron 1 in the transcription unit of maize gene constructs has been shown to increase gene expression in cultured maize cells. We have extended these studies with Adh1-S intron 1 using the firefly luciferase, Escherichia coli β-glucuronidase and chloramphenicol acetyltransferase reporter genes adjoined to different plant promoters and find enhancement of transient gene expression in all cases but one. We also show that the enhancement phenomenon can be mediated by the third intron of the maize actin gene. In all cases tested, the inclusion of an intron results in increased levels of steady-state RNA. The degree of enhancement depends on the exon sequences flanking the intron; flanking exons also influence the efficiency of intron splicing. Unexpectedly, unspliced RNAs accumulate during the transient assay.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 121
    ISSN: 1617-4623
    Keywords: Transposase ; DNA-binding protein ; Zea mays ; mobile DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The 3.5 kb long mRNA of the maize transposable element Ac contains an open reading frame (ORFa) which encodes a polypeptide of 807 amino acids, the putative transposase of Ac. The Ac mRNA is a rare transcript: we now estimate the fraction of Ac mRNA in wx-m7::Ac seedlings to be 2–13 × 10−5 of the polyA RNA. Assuming that maize cells contain similar amounts of polyA RNA as another monocot (0.16 pg/cell), this is equivalent to 1.5–10 transcripts in each cell. A protein with an apparent molecular weight of 112 kDa is detected, by five antisera directed against different segments of ORFa, exclusively in nuclear extracts from Ac-containing maize. This protein is most likely the full-length Ac ORFa protein. We estimate its concentration to be in the range of 3 × 10− of the nuclear proteins, or about 1000 molecules per triploid endosperm cell containing one Ac element.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 122
    ISSN: 1617-4623
    Keywords: Phosphoenolpyruvate carboxylase ; DNA binding protein ; Zea mays ; C4 plant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A plant nuclear protein PEP-I, which binds specifically to the promoter region of the phosphoenolpyruvate carboxylase (PEPC) gene, was identified. Methylation interference analysis and DNA binding assays using synthetic oligonucleotides revealed that PEP-I binds to GC-rich elements. These elements are directly repeated sequences in the promoter region of the PEPC gene and we have suggested that they may be cis-regulatory element of this gene. The consensus sequence of the element is CCCTCTCCACATCC and the CTCC is essential for binding of PEP-I. PEP-I is present in the nuclear extracts of green leaves, where the PEPC gene is expressed. However, no binding was detected in tissues where the PEPC gene is not expressed in vivo, such as roots or etiolated leaves. Thus, PEP-1 is the first factor identified in plants which has different binding activity in light-grown compared with dark-grown tissue. PEP-I binding is also tissue-specific, suggesting that PEP-1 may function to coordinate PEPC gene expression with respect to light and tissue specificity. This report describes the identification and characterization of the sequences required for PEP-1 binding.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 123
    ISSN: 1617-4623
    Keywords: α-Tubulin ; Zea mays ; In situ hybridization ; Developmental expression ; Antisense RNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In all eukaryotes α- and β-tubulins are encoded by small families of closely related genes and are highly conserved. In Zea mays, at least six different α-tubulin coding sequences are known. We describe the isolation from scutellar nodes of the maize inbred line W22 of a clone (CTM5) coding for an α-tubulin. On the basis of the 3′ end nucleotide sequence, this clone can be assigned to the already reported tua4 gene. Northern analysis demonstrates that CTM5 encodes a 1.5 kb transcript, which is expressed in different tissues of the seed and of the seedling. In order to define the spatial and temporal expression of α-tubulin genes, in situ hybridization experiments were performed on these tissues. Unexpectedly, a specific signal was detected with both antisense and sense RNA strands. Temporal and spatial distribution of the two RNAs, however, shows that high levels of the two transcripts are always discordant. In tissues where sense transcripts are highly abundant (embryos at various developmental stages, root tips, pollen grains), the antisense transcripts are expressed in relatively small amounts, while in pericarp, coleoptile, leaves, and scutellar node, where antisense transcripts accumulate, the sense transcript only reaches a very low level. Northern analysis using single-stranded DNA probes confirmed the presence of an antisense transcript of 1.5 kb, prompting speculation about the role of this transcript in the regulation of the expression of α-tubulin genes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 124
    ISSN: 1617-4623
    Keywords: Transcriptional activators ; O2 gene ; Zea mays ; bZIP proteins ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The aim of this research was to determine whether the structural homology between the O2 gene, a maize transcriptional activator, and the GCN4 gene, a yeast transcriptional factor, is reflected at the level of function. The O2 cDNA was cloned in the yeast expression vector pEMBLyex4 under the control of a hybrid, inducible promoter, and used to transform the yeast Saccharomyces cerevisiae. Transformed yeast cells produced O2 mRNA and a polypeptide immunoreactive with anti-O2 antibodies during growth in galactose. The heterologous protein was correctly translocated into the yeast nuclei, as demonstrated by immunofluorescence, indicating that the nuclear targeting sequences of maize are recognized by yeast cells. Further experiments demonstrated the ability of O2 to rescue a gcn4 mutant grown in the presence of aminotriazole, an inhibitor of the HIS3 gene product, suggesting that O2 activates the HIS3 gene, gene normally under control of GCN4. It was shown that the O2 protein is able to trans-activate the HIS4 promoter in yeast cells and binds to it in vitro. The sequence protected by O2, TGACTC, is also the binding site for GCN4. Finally, the expression of O2 protein in yeast did not produce alterations during batch growth at 30° C, while transformants expressing O2 protein showed a conditionally lethal phenotype when grown in galactose at 36° C; this phenotype mimics the behaviour of gcd mutants. The results support the idea that basic mechanisms of transcription control have been highly conserved in eukaryotes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 125
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 132 (1991), S. 159-163 
    ISSN: 1573-5036
    Keywords: enzymatical conversion ; organic-acid secretion ; proton secretion ; rhizosphere ; roots ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The participation of organic acids in the process of soil acidification was related to other H+ pumping processes. The ratio between efflux of organic acids and proton secretion of maize roots was determined with the use of a pH-stat combined with a collecting system for organic acids. Changes in the composition of carboxylic acids influenced by nitrogen supply were monitored by HPLC and via enzymatic conversion. The following substances were found to be secreted by maize roots: glycolate, glyoxylate, fumarate, 2-oxoglutarate and oxalate. Malate, however, could not be detected. There is no organic acid dominantly secreted by the roots, but changes are observed during aging which might result from deficiencies of nutrients e.g. P. Fertilization of N-deficient plants with urea leads to a significant change in the composition of acids secreted. In this case, oxalate was additionally detected with a concomitant increase in glyoxylate, indicating important changes in metabolism. Acidification of the rhizosphere is predominantly maintained by secretion of protons, not by efflux of organic acids, which contributed 0.2 to 0.3% to this process only. The role of organic acids in nutrient uptake is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 126
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 144 (1992), S. 199-205 
    ISSN: 1573-5036
    Keywords: acid phosphatase ; ectoenzymes ; naphthyl phosphate ; Picea abies ; rhizosphere ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract For in vivo demonstration of acid phosphatase activity in the rhizosphere of soil-grown plants filter papers were treated with a mixture of 1-naphthyl phosphate as substrate and the diazonium salt Fast Red TR as an indicator. After enzymatic hydrolysis, 1-naphthol forms a red complex with Fast Red TR. This method was applied to 8-day old maize plants and 3-year old Norway spruce plants growing in rhizoboxes in soil under non-sterile conditions. The treated filter paper is placed at the surface of roots and soil and acid phosphatase activity is visualized as a red-coloured ‘root print’ on the filter paper. The method can be used as a qualitative analysis of acid phosphatase in the rhizosphere. It also allows a rough estimate of phosphatase activity in different root zones.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 127
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 161 (1994), S. 225-232 
    ISSN: 1573-5036
    Keywords: minirhizotron ; root-length density ; soil core ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Detailed knowledge of the distribution of roots in the soil is important in understanding the extraction of water and nutrients from soil. Various techniques have been developed to monitor root-length density under field conditions. Excavation techniques, including soil cores, have long been considered to give reliable estimates of root-length density, but these techniques are laborious in sample collection and tedious in determination of root lengths. An attractive alternative for monitoring root-length density has been the minirhizotron whereby a periscope is inserted into a clear tube permanently installed in the soil for repeated and rapid measures of root development. The objective of this study was to compare the ability of the minirhizotron technique to measure root-length density as compared to the root-core technique. As in previous studies, substantial disagreement existed between the two techniques in the top 30-cm of the soil. The results from the minirhizotron consistently indicated a much lower root population than the root-core technique in the surface layer of soil. This is especially worrisome because more than 45% of the root-length density was found in this layer with the root-core technique. At deeper soil layers, the minirhizotron data proved to be no less variable than the root-core technique making the determination of statistically significant results difficult. Finally, the relationship between the minirhizotron and soil-core results varied with time even when the observations from the soil surface layer were ignored. Attempts to directly translate minirhizotron observations into a root-length density using a correlation approach would be suspect based on the results of this experiment.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 128
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 151 (1993), S. 97-104 
    ISSN: 1573-5036
    Keywords: aluminium ; ammonium ; induction ; maize ; nitrate ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Experiments with two maize (Zea mays L.) hybrids were conducted to determine (a) if the inhibition of nitrate uptake by aluminium involved a restriction in the induction (synthesis/assemblage) of nitrate transporters, and (b) if the magnitude of the inhibition was affected by the concurrent presence of ambient ammonium. At pH 4.5, the rate of nitrate uptake from 240 μM NH4NO3 was maximally inhibited by 100 μM aluminium, but there was little measurable effect on the rate of ammonium uptake. Presence of ambient aluminium did not eliminate the characteristic induction pattern of nitrate uptake upon first exposure of nitrogen-depleted seedlings to that ion. Removal of ambient aluminium after six hours of induction resulted in recovery within 30 minutes to rates of nitrate uptake that were similar to those of plants induced in absence of aluminium. Addition of aluminium to plants that had been induced in absence of aluminium rapidly restricted the rate of nitrate uptake to the level of plants that had been induced in the presence of aluminium. The data are interpreted as indicating that aluminium inhibited the activity of nitrate transporters to a greater extent than the induction of those transporters. When aluminium was added at initiation of induction, the effect of ambient ammonium on development of the inhibition by aluminium differed between the two hybrids. The responses indicate a complex interaction between the aluminium and ammonium components of high acidity soils in their influence on nitrate uptake. ei]{gnA C}{fnBorstlap}
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 129
    ISSN: 1573-5036
    Keywords: cultivar ; nitrate ; nitrate leaching ; N utilization ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In a 2-year field experiment conducted on a Gleyic Luvisol in Stuttgart-Hohenheim one experimental and nine commercial maize cultivars were compared for their ability to utilize soil nitrate and to reduce related losses of nitrate through leaching. Soil nitrate was monitored periodically in CaCl2 extracts and in suction cup water. Nitrate concentrations in suction water were generally higher than in CaCl2 extracts. Both methods revealed that all cultivars examined were able to extract nitrate down to a soil depth of at least 120 cm (1988 season) or 150 cm (1987 season). Significant differences among the cultivars existed in nitrate depletion particularly in the subsoil. At harvest, residual nitrate in the upper 150 cm of the profile ranged from 73–110 kg N ha−1 in 1987 and from 59–119 kg N ha−1 in 1988. Residual nitrate was closely correlated with nitrate losses by leaching because water infiltration at 120 cm soil depth started 4 weeks after harvest (1987) or immediately after harvest (1988) and continued until early summer of the following year. The calculated amount of nitrate lost by leaching was strongly influenced by the method of calculation. During the winter of 1987/88 nitrate leaching ranged from 57–84 kg N ha−1 (suction cups) and 40–55 kg N ha−1 (CaCl2 extracts), respectively. The corresponding values for the winter of 1988/89 were 47–79 and 20–39 kg N ha−1, respectively. ei]Section editor: B E Clothier
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 130
    ISSN: 1573-5036
    Keywords: ammonium assimilation ; carbon partitioning ; nitrate assimilation ; nitrogen partitioning ; Triticum aestivum ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The carbon and nitrogen partitioning characteristics of wheat (Triticum aestivum L.) and maize (Zea mays L.) grown hydroponically at a constant pH on either 4 mM or 12 mM NO3 - or NH4 + nutrition were investigated using either 14C or 15N techniques. Greater allocation of 14C to amino-N fractions occurred at the expense of allocation of 14C to carbohydrate fractions in NH4 +-compared to NO3 --fed plants. The [14C]carbohydrate:[14C]amino-N ratios were 1.5-fold and 2.0-fold greater in shoots and roots respectively of 12 mM NO3 --compared to 12 mM NH4 +-fed wheat. In both 4 mM and 12 mM N-fed maize the [14C]carbohydrate:[14C]amino-N ratios were approximately 1.7-fold and 2.0-fold greater in shoots and roots respectively of NO3 --compared to NH4 +-fed plants. Similar results were observed in roots of wheat and maize grown in split-root culture with one root-half in NO3 --and the other in NH4 +-containing nutrient media. Thus the allocation of carbon to the amino-N fractions occurred at the expense of carbohydrate fractions, particularly within the root. Allocation of 14N and 15N within separate sets of plants confirmed that NH4 --fed plants accumulated more amino-N compounds than NO3 --fed plants. Wheat roots supplied with 15NH4 + for 8 h were found to accumulate 15NH4 + (8.5 μg 15N g-1 h-1) whereas in maize roots very little 15NH4 + accumulated (1.5 μg 15N g-1 h-1) It is proposed that the observed accumulation of 15NH4 + in wheat roots in these experiments is the result of limited availability of carbon within the roots of the wheat plants for the detoxification of NH4 +, in contrast to the situation in maize. Higher photosynthetic capacity and lower shoot: root ratios of the C4 maize plants ensure greater carbon availability to the root than in the C3 wheat plants. These differences in carbon and nitrogen partitioning between NO3 --and NH4 +-fed wheat and maize could be responsible for different responses of wheat and maize root growth to NO3 - and NH4 + nutrition.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 131
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 155-156 (1993), S. 159-161 
    ISSN: 1573-5036
    Keywords: amino acid ; cell suspension culture ; nitrate uptake ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effect of amino acids on nitrate transport was studied in Zea mays cell suspension cultures and in Zea mays excised roots. The inclusion of aspartic acid, arginine, glutamine and glycine (15mM total amino acids) in a complete cell-culture media containing 1.0 mM NO3 - strongly inhibited nitrate uptake and the induction of accelerated uptake rates. The nitrate uptake rate increased sharply once solution amino acid levels fell below detection limits. Glutamine alone inhibited induction in the cell suspension culture. Maize seedlings germinated and grown for 7 days in a 15 mM mixture of amino acids also had lower nitrate uptake rates than seedlings grown in 0.5 mM Ca(NO3)2 or 1 mM CaCl2. As amino acids are the end product of nitrate assimilation, the results suggest an end-product feed-back mechanism for the regulation of nitrate uptake.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 132
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 165 (1994), S. 315-321 
    ISSN: 1573-5036
    Keywords: cell wal's ; epidermis ; growth ; root development ; soil penetration ; stiffness ; Zea diploperennis ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The development of the epidermal layer of roots of Zea is traced from the quiescent centre to the zone where root hairs develop. In the zone of cell division a three layered coat forms on the outside of the epidermal cells consisting of the outer epidermal walls, overlaid by a two-layered pellicle composed of a thick fibrillar inner layer of polysaccharide, and a thin fibrillar outer layer of protein. The epidermal cells divide several times in the same longitudinal file but rarely across a radius to give a new longitudinal file. Thus, the radial walls become much thicker than all but the original transverse walls, and packets of up to 32 daughter cells derived from a single initial may be distinguished. The pellicle develops during these divisions as a continuum over the outer walls of the daughter cells. It is proposed that the pellicle provides a stiffening to the forward end of the root which permits it to penetrate soil without bending. Support for this hypothesis is shown by the Zea mays mutant Ageotropic in which the pellicle is absent, the epidermal surface is disorganized, and which grows crookedly through soil. In the zone of extension growth of normal roots of two Zea species the pellicle thins and disappears. Circumferential strips of the pellicle were peeled off the young epidermal cells and could be stretched to twice their length. This deformation is partly the result of the pellicle stretching and breaking above the attachments of the radial walls. After normal thinning of the pellicle, detachment of the radial walls at their outer ends produces a corrugated surface in the proximal zone of the root tips. In dicotyledons (e.g., soybean), there is no similar pellicle, but a stiff root tip is produced by a long multi-layered root cap, the proximal portion of which covers the elongating epidermal surface.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 133
    ISSN: 1573-5044
    Keywords: bialaphos ; glufosinate ; phosphinothricin ; l-proline ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effectiveness of four phosphinothricin (PPT)-based selective agents were evaluated for use in maize transformation: glufosinate, bialaphos, Basta® and Herbiace®. Glufosinate and its commercial formulation, Basta®, were less effective in controlling growth of non-transgenic corn callus than the tripeptide, bialaphos, or its commercial formulation, Herbiace®. Addition of 25 mM l-proline had no significant effect on selection when using bialaphos. However, when l-proline was included with the selective agent glufosinate, selection was inhibited and callus growth was enhanced. At four weeks, callus growth on 0.3, 1.0 and 3.0 mg l-1 glufosinate in the presence of proline was 76, 43, and 21% of control growth, respectively, and in the absence of proline was only 32, 9, and 6% of control growth. Optimized selection protocols for Basta® and bialaphos yielded comparable numbers of transformants. Using these protocols, fertile transgenic plants were regenerated from transformed callus cultures.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 134
    ISSN: 1573-5060
    Keywords: Breeding ; heritability ; in vitro digestibility ; in vivo digestibility ; maize ; silage maize ; variation ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Variation and covariation for agronomic and digestibility traits of silage maize are reported from a compilation of 22 years of experiments with standard sheep. Genotype effects of DOM and DCF were highly significant, even when genotypes were nested in earliness groups or brown-midrib hybrids discarded (Table 2). The genetic variance of crude fiber content was low, but the variance of the DCF was high. The genetic variance of DOM was about 4 times lower than genetic variance of DCF, but broad sense heritability of DOM was higher because of lower residual variance (Table 3). Genetic correlations between grain or crude fiber content and DOM had similar absolute values, 0.65, so each of these two traits was an important but not the unique determinant of silage maize quality. There was no correlation between DCF and grain or crude fiber content. Yield was not related to DOM or DCF within each group of earliness, allowing some quality improvement without agronomic drift (Table 4). Except for late hybrids, most of DOM differences between groups of earliness came from lowering of minimum value, while maximum values were similar. It was the contrary for DCF, with similar minimum values for all groups (Table 5). There was no obvious correlation between year of registration of hybrids and DOM or DCF, but extra new variation seemed obtained only for low values (Figs 1, 2; Table 6). IVDOM according to the APC process was a poor predictor of DOM, especially when brown-midrib hybrids and earliness effects were discarded; but because heritability of this trait was similar to DOM heritability, such enzymatic processes could probably be used to avoid drift towards poor DOM with hybrids bred for higher stalk strength.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 135
    ISSN: 1573-5060
    Keywords: abscisic acid ; inheritance ; drought stress ; Zea mays ; maize
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary This study analyzes the components of phenotypic variation for abscisic acid (ABA) content in maize (Zea mays L.) leaves and the correlations with drought sensitivity index (DSI) and silk delay (SD), involved in the reaction to water deficit. Eight early- and seven medium-maturity inbreds were examined in field trials: in 1990 with low irrigation volume and in 1991 with low and high irrigation volumes. ABA concentration and DSI were investigated at growth stages (S) corresponding to stem elongation (S3), appearance of the first husks (S4), and mid-end of silking (S5). The ABA concentration was significantly higher in conditions of water deficit and in the later growth stage. The genetic component for ABA concentration attained higher relative values than those shown by DSI in the same growth stages and by SD; moreover, it increased from growth stage 3 to stage 5. The genotype × year and genotype × irrigation volume interactions were smaller for ABA concentration than for DSI and SD. The broad sense heritability on a plant basis, estimated in drought conditions, for ABA concentration ranged from 21.4 to 55.1% according to maturity group and growth stage. A wide variation was observed among lines for ABA concentration: the medium-maturity group showed a three-fold range (from 219 to 605 ng ABA g−1 dry weight). No clear relationships between ABA concentration, DSI and SD were found. These results indicate the feasibility of a selection for ABA concentration within segregating populations derived from crosses between the inbred lines herein tested.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 136
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 46 (1990), S. 237-247 
    ISSN: 1573-5060
    Keywords: Zea mays ; maize ; genetic variation ; prediction ; dry matter yield ; early vigour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Evidence of genetic variation for early vigour is presented using maize line × tester crosses. The leaf appearance rate and associated variance components are affected by a physiological stress attributable to the transition to autotrophic nutrition by the plant. At this stage, specific combining ability plays an important role in the total genetic variation. It is concluded that differing genetic controls exist in early and late material, and that this difference is also manifested in leaf initiation and elongation rates. The ground coverage rate, as a component of plant development, is genetically correlated to total dry matter yield. The genetic correlations vary according to the growth stage.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 137
    ISSN: 1573-5060
    Keywords: Zea mays ; maize ; forage ; digestibility ; near infrared reflectance spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Near infrared reflectance spectroscopy (NIRS) is emerging as a potentially useful tool in breeding plants for quality traits. Information is lacking, however, on its use in forage maize (Zea mays L.). The objectives of the present investigation were to evaluate the prediction of digestibility traits of maize stover using NIRS technique and to study the effect of laboratory (Lab) and NIRS assays on the estimates of variation and covariation. Twelve inbred lines, 66 diallel crosses among them and eight hybrid checks were evaluated at silage and grain harvests for 2 years at two agro-climatically diverse locations in the Federal Republic of Germany. Standard methods were used for Lab analysis of in vitro digestible organic matter (IVDOM), neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL). In NIRS evaluation, calibration equations were developed by modified stepwise regression. The standard error of calibration was 2.5, 1.7, 1.4 and 0.4 for IVDOM, NDF, ADF and ADL, respectively. The coefficient of multiple determination was high (≥0.9) except for ADL. The validation statistics (standard error and correlation coefficient) were similar. In the diallel crosses, the estimates of variation (heritabilities in broad and narrow sense, genotypic and error coefficients of variation), generally, did not vary appreciably and consistently in the comparisons between Lab and NIRS methods particulary at silage harvest. Simple and rank correlations between Lab and NIRS analyses were positive and significant. These correlation coefficients based on the mean performance of the diallel crosses at silage harvest were 〉0.9 and at least 16 hybrids were common between the two analyses, among the upper one-third or lower one-third (22) hybrids. The study showed that NIRS analysis should be useful in maize breeding programmes wherein a large number of genotypes need to be evaluated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 138
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 48 (1990), S. 63-72 
    ISSN: 1573-5060
    Keywords: Zea mays ; maize ; corn ; yield ; kernel weight ; shelling percentage ; plant height ; ear height ; husk weight ; cob weight
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary White-endosperm (y y y) maize (Zea mays L.) is vital to the maize dry-milling industry. However, a substantially greater acreage in the U.S.A. is planted to yellow (Y Y Y) than white maize. Data on comparative performance of yellow and white maize is scanty, and results are inconclusive. This field study was conducted to provide information on dosage effects of y gene on grain yield, 500-kernel (K) weight, shelling percentage, plant and ear height, and cob weight. Yellow x yellow, yellow x white, and white x white endosperm crosses were made among five yellow and five white endosperm lines of Mo14W × Oh7B parentage. In the material studied, the genetic complement of the white-endosperm parent Mo14W varied from 12.50% to 87.50% across 15 treatments. The effect of Mo14W dosages among treatments was removed through analysis of covariance. If differences among treatment means existed, they were attributed to the y gene. A test of parallelism among regression coefficients (Ho. β1=β2=---β15=βc) indicated that these regressions coefficients for plant height, ear height, 500-K weight, and husk weight showed parallelism across yellow x yellow, yellow x white, and white x white crosses. Differences in plant height were significant in 3 out of 5 comparisons each between Y Y vs. y y, Y y vs. y y, and Y Y vs. Y y. Differences in ear height were significant in 1 of 5 Y Y vs. y y comparisons, in 3 of 5 Y y vs. y y comparisons, and in 1 of 5 Y Y vs. Y y comparisons. Differences in 500-K weight were significant in 4 of 5 Y Y vs. y y, in 2 of 5 Y Y vs. Y y and in 1 of 5 Y y vs. y y comparisons. Differences in husk weight were significant in all the Y Y vs. y y comparisons, in 4 of 5 Y y vs. y y comparisons, and in 1 of 5 Y Y vs. Y y comparisons. An increase in the y gene dosage caused, in general, a significant decrease in grain yield, 500-K weight, plant height, ear height, and husk weight. Shelling percentage was decreased but not appreciably. The Y y combination had a heterotic effect on plant height, ear height, and cob weight. An implication of the findings of this study is that it would be difficult to breed for high-yielding white maize if one used this y gene source. At this time, this is the only source (chromosome 6) available for white-endosperm maize. Non-parrallelism among regression coefficients was noted for shelling percentage, grain yield, and cob weight. Non-parallelism was observed in shelling percentage of the yellow x yellow crosses, cob weight of the yellow x white crosses and in grain yield of both yellow x yellow and yellow x white crosses. In general, an increase in mean Mo14W dosage resulted in increased grain yield. Mo14W dosages generally reduced cob weight in the yellow x white crosses. Shelling percentage increased as the mean Mo14W dosages increased for the yellow x yellow crosses. An increase in Mo14W dosages resulted in an increase in 500-K weight.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 139
    ISSN: 1573-5060
    Keywords: Zea mays ; forage maize ; stover ; nutritive value ; heritability ; quantitative inheritance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The maize populations BS13 (S2) C4 and Lancaster are compared with respect to their potential as forage maize. In light of the preliminary results, the Lancaster population was chosen for a more thorough study. The determination of NDF gave a sufficiently precise estimate of the stover digestibility within our experimental conditions. The heritability of stover and grain production was 0.59 and 0.30, respectively, whilst that of the stover NDF was 0.32. The additive genetic correlation between NDF and stover production, possibly attributable to the architecture of the plant, favours the selection of genotypes that produce more and better forage.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 140
    ISSN: 1573-5060
    Keywords: Zea mays ; maize accessions ; teosinte ; mature pollen ; heat tolerance ; pollen tube length ; pollen viability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The effects of high temperature on mature pollen of various maize lines were investigated. Genotypic differences in pollen reaction to high temperature were revealed. Pollen grains resistant to high temperature (35°C, 26°C) were characterized by higher germination capacity and better ability to develop normal pollen tubes. The studies are of interest to evaluate reproductive system tolerance and conduct gamete selection at the mature pollen grain stage in maize.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 141
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 56 (1991), S. 97-105 
    ISSN: 1573-5060
    Keywords: growth regulators ; dimethyl sulfoxide ; Zea mays ; apomixis ; chemical induction ; maize seed set
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Silks of 18 maize (Zea may L.) F1 hybrids were treated with different combinations of 9 growth regulators, colchicine, and dimethyl sulfoxide (DMSO) for the purpose to induce apomixis (agamospermy) in 1988 and 1989. Hybrid K301 × K303 gave the highest (0.36%) average frequency of seed induction among the hybrids. The most effective treatments were DMSO, gibberellic acid plus 6-benzyl aminopurine (6-BA), and DMSO plus methanesulfonic acid. Individually, the highest frequency of seed induction was 1.4% for hybrid K731×K306 when treated with α-naphthalene acetic acid (NAA)-zeatin mixture. The frequency of seed induction seemed to depend partially on the interaction between chemicals and hybrids. Cytological observation of root-tip cells indicated that the majority of the seeds obtained were diploid, some were mixoploid, and a few were haploid. Diploid plants from induced seeds from the same parent were morphologically uniform and resembled the parent. Variations in plant and ear heights were comparable to those of the hybrid parent. Cytological and morphological investigations suggested that the chemically induced seeds originated mainly from somatic tissue but occasionally came from reduced cells in the embryo sac, leading to haploids. The results showed that chemical induction of adventitious embryony in maize hybrids is possible, but the more effective chemicals, their concentrations, and ways of application for increasing the frequency of seed induction need to be explored for practical use.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 142
    ISSN: 1573-5060
    Keywords: cold tolerance ; correlated responses ; germination ; kernel type ; kernel weight ; recurrent selection ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Four cycles of divergent full-sib recurrent selection for the ability to germinate at low temperature were conducted in a maize (Zea mays L.) F2 population. The selection criterion was the high (H) or the low (L) value in algebraic terms of the difference (DG) between germination percentage at 9.5°C (G9.5) detected 19 days after sowing and germination percentage at 25°C (G 25) seven days after sowing; both traits were evaluated in a controlled environment (germinator). Direct and correlated responses estimated during the course of selection were in accordance with those evaluated at the end. Selection for H led to populations with higher DG values, while the reverse was noted for L; differences between H and L populations increased in successive selection cycles, though divergence tended to level off. Selection for H also resulted in higher G 9.5 (day 19), shorter germination time and more flinty kernels, while selection for L led to responses in the opposite direction as well as to a lower G 9.5 detected 37 days after sowing (i.e. at the end of germination). In contrast, responses were negligible for G 25 and varied erratically from one cycle to another for kernel weight.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 143
    ISSN: 1573-5060
    Keywords: Zea mays ; glutathione-S-transferase ; glutathione ; herbicide tolerance ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Crop improvement for tolerance to specific herbicides is an important breeding target, since molecules performing well with regard to environmental safety are frequently not completely selective for crops. The glutathione (GSH)/glutathione-S-transferase (GST) system is a general mechanism of detoxification that in higher plants may confer tolerance to some herbicides. GSH level and GST activity were measured in different maize inbred lines, in the absence or in the presence of EPTC (a thiocarbamate) and of Alachlor (a chloroacetanilide); a wide genetic variability was observed for these parameters, which appear to be involved in plant tolerance to herbicides. Isozyme analysis was performed on roots, leaves, scutellum, pollen, coleoptile, mesocotyl of the same inbreds: it revealed the presence of many GST forms in maize, showing high polymorphism; they are controlled by at least five genes, the expression of which is developmentally regulated in the different tissues analyzed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 144
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 70 (1993), S. 105-111 
    ISSN: 1573-5060
    Keywords: maize ; genotype × environment interaction ; stability analysis ; cultivar testing ; YSi statistic ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Genotype × environment (GE) interaction complicates selection of superior genotypes across environments. The main objective of this study was to select maize (Zea mays L.) genotypes via a new yield-stability (YSi) statistic in yield trials conducted in Albania. Another objective was to estimate contribution of environmental index (% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0dh9WrFfpC0xh9vqqj-hEeeu0xXdbba9frFj0-OqFf% ea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr% 0-vqpWqaaeaabaGaaiaacaqabeaadaqaaqaaaOqaaiqadIfagaqeaa% aa!3851!\[\bar X\]·j − % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0dh9WrFfpC0xh9vqqj-hEeeu0xXdbba9frFj0-OqFf% ea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr% 0-vqpWqaaeaabaGaaiaacaqabeaadaqaaqaaaOqaaiqadIfagaqeaa% aa!3851!\[\bar X\].., where % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0dh9WrFfpC0xh9vqqj-hEeeu0xXdbba9frFj0-OqFf% ea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr% 0-vqpWqaaeaabaGaaiaacaqabeaadaqaaqaaaOqaaiqadIfagaqeaa% aa!3851!\[\bar X\]·j is mean of all genotypes in the jth environment and % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0dh9WrFfpC0xh9vqqj-hEeeu0xXdbba9frFj0-OqFf% ea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr% 0-vqpWqaaeaabaGaaiaacaqabeaadaqaaqaaaOqaaiqadIfagaqeaa% aa!3851!\[\bar X\]is mean of all genotypes across all environments), minimum temperature, maximum temperature, preseason rainfall, rainfall during the growing season, and relative humidity to GE interaction by determining heterogeneity (nonadditivity) attributable to each of these environmental factors. In five of eight trials, heterogeneity due to environmental index was significant. Heterogeneity due to the other environmental factors was not significant in any trial. A comparison of δ i 2 (stability-variance statistic derived from total GE interaction) and s i 2 (stability-variance statistic derived from residual GE interaction following removal of heterogeneity due to encovariate) helped identify genotypes that performed stably or unstably because of a linear effect of environmental index. In three of the five trials showing significant heterogeneity due to environmental index, the YSi statistic selected a reduced number of unstable genotypes as compared with selection based solely on yield. However, the circumstances or conditions under which YSi and solely yield-based method select the same or different genotypes are not fully understood.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 145
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 72 (1993), S. 87-94 
    ISSN: 1573-5060
    Keywords: Zea mays ; maize ; pollen storage ; pollen grain viability ; pollen enzymes ; pollen physiology ; enzyme cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Maize pollen quality was investigated after long-term storage both in a refrigerator and in liquid nitrogen by a combination of viability tests and cytochemical methods. Determination of the activities of a number of enzymes involved in important metabolic pathways was carried out. Quinone formation was also studied, as some products of secondary metabolism affect pollen grain viability. One year of pollen storage in liquid nitrogen had little effect on the activities of oxidoreductases and hydrolases and had no significant effect on pollen grain viability evaluated by acetocarmine, neutral red and acridine organe. Only the FCR test showed slightly decreased viability. After one and two years of storage in a refrigerator, pollen grain viability, tested using acetocarmine, neutral red and acridine orange, did not change substantially. Simultaneously the FCR test showed a considerable decrease in pollen grain viability. Long-term storage in a refrigerator resulted in the loss of cytochrome oxidase activity and rise of alcohol dehydrogenase, lactate dehydrogenase, peroxidase and polyphenoloxidase activities as well as of quinone formation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 146
    ISSN: 1573-5079
    Keywords: chlorophyll fluorescence induction ; field studies ; Helianthus annuus ; Phaseolus vulgaris ; photoinhibition ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract It was tested whether field-grown plants (Phaseolus vulgaris, Zea mays and Helianthus annuus) reflect photoinhibitory effects under natural conditions. Attached leaves were used for determination of the photochemical capacity of Photosystem II (Fv/Fm) by means of a portable fluorimeter (PSM, BioMonitor, S.). For a more qualitative description of Fv/Fm, the modifications of the absolute values F0, Fm as well as of the half-rise time of Fm (T/2) were also considered. By comparing artificially shaded and ‘sun exposed’ plants, the direct influence of light on the photochemical capacity was investigated. Under low natural light conditions the differences of the photochemical capacity between shaded and ‘sun exposed’ leaves were negligible in all three species. On a day with full sunlight a decline of Fv/Fm was observable at noon-time in the ‘sun exposed’ leaves of all three species, although the absolute values differed between the species compared. Additionally, the extent of the recovery of Fv/Fm was varying. Both phenomena could be due to differences in the photosynthetic apparatus (e.g., C3−C4, ontogenetic stage, sun-shade type), to self-shading phenomena (comparing leaf layers of Zea and Helianthus) or to differences in the activity of repair mechanisms possibly caused by other environmental factors (vapour pressure deficit = VPD, drought and temperature phenomena). Nevertheless, the results of the shading experiments and the comparison of species lead to the conclusion that primarily light-induced reduction of the photochemical capacity appears at noon in leaves exposed to full sunlight, a partial restoration of Fv/Fm takes place till the evening. Artifically shaded plants show only a slight alteration of the photochemical capacity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 147
    ISSN: 1573-5036
    Keywords: fumigation ; Glomus intraradices ; G. vesiculiferum ; G. versiforme ; Glycine max, grass-legume mixture ; 15N ; nitrogen transfer ; soil microorganisms ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effect of mycorrhizal inoculation on 15N transfer from soybean to maize was studied in fumigated and non-fumigated soil. Three Glomus species and a non-inoculated control were compared. In spite of higher levels of root colonization and more abundant hyphae associated with plants growing in fumigated soil, mycorrhizae-enhanced 15N transfer to maize was significant only in non-fumigated plots. High 15N transfer was not only associated with high mycelium density in soil but also with low soil microbial carbon, suggesting that the effect of mycorrhizal fungi on soil microbial populations may be an important factor affecting N transfer between mycorrhizal plants.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 148
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 165 (1994), S. 293-300 
    ISSN: 1573-5036
    Keywords: gravitropism ; living systems theory ; nutation ; Phleum pratense L. ; simulation ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Roots have the ability to change the direction of their forward growth. Sometimes these directional changes are rapid, as in mutations, or they are slower, as in tropisms. The gravitational force is always present and roots have an efficient graviperception mechanism which enables them to initiate gravitropic movements. In trying to model and simulate the course of gravitropic root movements with a view to analyse the component processes, the following aspects of the plant's interaction with gravity have been considered: (1) The level of organization (organism, organ, cell) at which the movement process is expressed; (2) whether the gravity stimulation event is dynamic or static (i.e. whether or not physiologically significant displacements take place with respect to the gravity vector); (3) the sub-systems involved in movement and the processes which they regulate; (4) the mathematical characterization of the relevant sub-systems. A further allied topic is the nature of nutational movements and whether they are linked with gravitropic movements in some way. In considering how they can best be modelled, two types of nutational movements are proponed: stochastic nutation and circumnutation. Most, if not all, natural movements developed in response to static gravistimulation can be viewed as gravimorphisms. This applies at the levels of cell, organ and organism. However, when a system at any one of these levels experiences dynamic gravistimulation, because of its inherent homeostatic properties, it is induced to regenerate a state similar to that previously held. Thus, gravitropism is a regenerative gravimorphic process at the level of the organ.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 149
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 150 (1993), S. 255-262 
    ISSN: 1573-5036
    Keywords: carbon dioxide ; ethylene ; Glycine max ; rhizosphere ; Sorghum bicolor ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A method for collecting low volumes of soil gas from a small region, and a technique for determining small concentrations of ethylene using an enrichment process are described. Using these methods, it was found that ethylene and carbon dioxide (CO2) concentrations of soils varied considerably depending on the presence or absence of a rhizosphere. Ethylene was much higher (31–375 nL L−1; mean: 207) in non-cropped areas (i.e., soils without rhizosphere) than in the rhizosphere region (8–136 nL L−1; mean: 38) of a field in which maize or soybean were grown. On the other hand, CO2 concentrations were higher in rhizosphere than in non-rhizosphere soil, especially in pot experiments. The rate of ethylene decomposition was, however, much greater in rhizosphere soil (55 nL g−1 day−1) than in non-rhizosphere soil (34 nL g−1 day−1). Higher microbial activity was presumed to result in the decrease of ethylene concentration and the increase in CO2 in rhizosphere regions. The implications of these results in relation to the influence of ethylene in rhizosphere on plant growth, and the role of soil microbes on decomposition of ethylene is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 150
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 163 (1994), S. 267-277 
    ISSN: 1573-5036
    Keywords: cultivar ; critical root length density ; field experiment ; nitrate ; N utilization ; root growth ; uptake rate ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In a 2-year field study conducted on a high fertilized Gleyic Luvisol in Stuttgart-Hohenheim significant differences among 10 maize cultivars were observed in soil nitrate depletion. The different capability of the cultivars to utilize nitrate particularly from the subsoil was positively correlated with (a) shoot N uptake at maturity, and (b) root length density (Lv) in the subsoil layers at silking. “Critical root length densities” for nitrate uptake were estimated by (a) calculating uptake rates per unit root length (U), (b) subsequent calculation of needed nitrate concentration in soil solution (C1) to sustain calculated U according to the Baldwin formula, and (c) reducing measured Lv and proportionate increase of U until needed concentration equaled measured concentration. Uptake rate generally increased with soil depth. “Critical root length densities” for cultivar Brummi (high measured root length densities and soil nitrate depletion) at 60–90 cm depth ranged from 7 % (generative growth) to 28 % (vegetative growth) of measured Lv Measured root length density of each other cultivar was higher than “critical root length density” for Brummi indicating that the root system of each cultivar examined would have been able to ensure N uptake of Brummi. Positive relationships between root length density and nitrate utilization as indicated by correlation analysis therefore could not be explained by model calculations. This might be due to simplifying assumptions made in the model, which are in contrast to non-ideal uptake conditions in the field, namely irregular distribution of roots and nitrate in the soil, limited root/soil contact, and differences between root zones in uptake activity. It is concluded from the field experiment that growing of cultivars selected for high N uptake-capacity of the shoots combined with “high” root length densities in the subsoil may improve the utilization of a high soil nitrate supply.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 151
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 167 (1994), S. 127-134 
    ISSN: 1573-5036
    Keywords: herbicides ; chlorsulfuron ; metsulfuron methyl ; root cap ultrastructure ; root growth ; Pisum sativum ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Herbicide residues may affect seedlings during early stages of their development. We studied this possibility by the use of light and electron microscopy after incubation of germinating seeds ofPisum sativum L. andZea mays L. with different concentrations of chlorsulfuron and metsulfuron-methyl. By in vitro experiments, we have shown that both herbicides caused growth reduction of the very young roots, and severe ultrastructural alterations and injuries of the root caps of both species. Chlorsulfuron caused increase of electron-dense material in the vacuoles, cytoplasmic degeneration even in the inner secretory cell layers of the cap, and disruption of the amyloplast envelopes with release of the statolithic starch grains. In the initial cell complex of the root cap, the herbicides caused the formation of large concentric aggregates of the rough ER and wall disformations in the cells adjacent to this complex. Scanning electron microscopic observations revealed a decrease of the slime layer ensheathing the root cap and the subapical root surface. We conclude that even in early stages of seed germination, both herbicides seriously affect the gravity perception centre (consisting of the statocytes), and the secretory tissue of the root caps, thus probably disturbing the processes of gravitropism and the protective slime secretion of the roots.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 152
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 28 (1992), S. 129-137 
    ISSN: 1573-5044
    Keywords: cms-T ; in vitro selection ; methomyl resistance ; mitochondrial mutation ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Several factors affecting the success of selection in plant populations were examined for their relevance to in vitro selection. Three in vitro selection schemes and two growth assessment procedures were evaluated for effectiveness in selecting for a mitochondrial trait in maize: resistance to the insecticidal compound methomyl. Regenerable maize callus was derived from immature embryos of the three-way hybrid P39/IL766A2 x W182BN containing Texas male sterile cytoplasm (cms-T). Either low, gradually increasing, or high selection pressures were used to grow callus over a period of 3–5 months. There was no significant difference in recovery of resistant plants using these 3 methods. Growth of callus on medium containing methomyl was assessed by increase in fresh weight during the final month of selection or by increase in number of callus pieces over the course of selection. These quantitative measures of growth were unreliable indicators for gain in resistance within the callus population. A procedure for recovery of methomyl resistant and male-fertile cms-T plants is suggested.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 153
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 45 (1990), S. 131-137 
    ISSN: 1573-5060
    Keywords: Zea mays ; maize ; acetochlor ; heterosis ; susceptibility ; tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The variation of response to acetochlor was studied in a two-year experiment carried out by subjecting 18 maize (Zea mays L.) inbred lines to three herbicide rates (0, 2.5 and 5 l a.i./ha). In both years some inbred lines consistently exhibited an evident susceptibility, with symptoms consisting of the seedling curling up below the soil surface and causing impaired field emergence. The results were poor plant density and lower grain yield in comparison to control. In contrast, other lines showed a satisfactory level of tolerance. Then, to gather data on the inheritance of response to acetochlor, four tolerant inbreds (T) and four susceptible inbreds (S) were crossed to obtain four T×T, four S×S, four S×T and the corresponding four T×S two-way hybrids. These hybrids were studied together with parental lines by applying the same herbicide rates used in the previous trial. The S×S hybrids showed susceptibility to the herbicide and the T×T were tolerant, whereas the S×T and the T× S hybrids showed a tolerance very close to that of the T×T hybrids. No difference was found between S×T and the corresponding T×S hybrids as to herbicide response. On average, the 16 hybrids exhibited greater tolerance than the eight parental lines, with each hybrid group being more tolerant than its parental line group. These results indicate that tolerance to acetochlor is prevailingly dominant, that action of extranuclear genes should be ruled out, and that the level of plant vigour can affect herbicide reactiveness.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 154
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 45 (1990), S. 257-266 
    ISSN: 1573-5060
    Keywords: Zea mays ; maize breeding ; honeycomb selection ; inbred line development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The production of seed of the maize single cross hybrid F68*NE2 is uneconomic because of the low grain yield of the maternal line. Therefore the aim was to produce it from newly developed inbred lines obtained by reshuffling the genes in the hybrid, accompanied by selection. Thus in open pollinating generations derived from this hybrid, i.e. in C0, C1, C2, C3 and C4, honeycomb selection for grain yield improvement was applied. Selfing of one ear and open pollination of another ear of selected prolific C4 plants yielded 20 pairs of S1/half sib progenies. Plants grown from remnant S1 seed corresponding to superior progeny pairs were selfed. In each S2-line a single plant was selected and selfed. The S3-lines were evaluated for yield. Two S3-lines, i.e. 6D and 2B, attracted attention because they yielded two and a half times as much as the best commercial inbred line B73. The S1-and S2-lines were tested for combining ability with the related inbred lines NE2 and F68 by means of honeycomb design experiments and for combining ability with unrelated, freely available inbred lines by means of randomized complete block designs. Two S2-lines, i.e. 5C and 6E, were selected for their good combining ability. The six single cross hybrids produced by crossing the four S3-lines 6D, 2B, 5C, and 6E were compared with the original hybrid F68*NE2 in a honeycomb design at two sites. The grain yields of the single cross hybrids 6D*6E and 5C*6E were similar to that of F68*NE2. However, these two reconstructed hybrids can be produced in a cheaper way because the new maternal inbred lines yield as good as B73 (line 5C) or much better (line 6D).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 155
    ISSN: 1573-5060
    Keywords: Zea mays ; maize ; Ostrinia nubilalis ; European corn borer ; resistance ; taxonomy ; germplasm ; indigenous land races
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The resistance to the European corn borer, Ostrinia nubilalis (Hubner), of thirty-seven indigenous landraces of Mexican maize was examined. The relationship of resistance and existing taxonomy of maize according to Wellhausen et al., (1952), was subjected to numerical analyses. Variables examined were: seedling DIM-BOA content, the extent of leaf feeding damage by early instar larvae both in the field and in the laboratory, the extent of plant breakage and stalk tunneling by late instar larvae, plant height, and the extent of fungal damage by Gibberella zeae and Ustilago maydis. Significant differences in resistance among the major taxonomic groupings were reflected in the existing taxonomy of maize (Wellhausen et al., 1952). The most resistant landrace grouping was Wellhausen et al.'s Prehistoric Mestizos. Eighty-five percent of a series of modern inbred lines, pools, and Argentine landraces were found to have affinities with one of the more susceptible groupings, the Ancient Indigenous Races, based upon analysis of the resistance data.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 156
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 51 (1990), S. 19-23 
    ISSN: 1573-5060
    Keywords: Zea mays ; maize ; corn ; Aspergillus flavus ; Aspergillus parasiticus ; aflatoxin ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Contamination of maize (Zea mays L.) grain prior to harvest with aflatoxin frequently occurs in the southern U.S.A. and sources of resistance are needed. Maize from twelve genotypes (varieties) crossed to two testers was analyzed for aflatoxin B1 (AFB1) contamination at Baton Rouge, LA and Tifton, GA in 1987. Variety Philippines had the lowest amount of AFB1 at Baton Rouge and one of the lowest amount of AFB1 at Tifton. In the combined analysis of variance, the location x treatment x tester x variety interaction was significant. This interaction was analyzed and a stability variance (σ1 2) statistic calculated. Mean AFB1 accumulation and stability of AFB1 production were examined simultaneously, i.e., variety ranks for AFB1 and σ1 2 were summed. The most desirable (lowest rank sum) variety across locations, testers, and treatments (inoculation and control) was St. Charles White, followed by Delta Prolific White, and Hopi. The most inconsistent AFB1 accumulation, along with high AFB1, was on Fino, Atkinson, USAWI, Navajo, and Michoacan-21. The ranks of varieties between the inoculation and control treatments were different (rs=−0.51 for Baton Rouge and 0.29 for Tifton). The rs (rank correlation coefficient) for the control treatments between Baton Rouge and Tifton was 0.60 (P〈0.05) and that for the inoculation treatments was −0.20. The varieties identified in this study as having relatively low concentration of AFB1 should be useful to maize breeders in reducing AFB1 contamination in field maize.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 157
    ISSN: 1573-5060
    Keywords: Zea mays ; maize ; genetic variation ; nitrate accumulation ; N use efficiency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The objective of this research was to obtain information about expression of genes controlling N concentration in the lower stalk internodes of maize at silking stages and in two other stages during the grain filling period. The inheritance of nitrate-N concentration, total N concentration, and the nitrate-N/total N ratio in the lower stalk internodes was measured in an eight-line diallel cross experiment and in an experiment involving segregating generations. The results show that the parameters examined, particularly nitrate-N concentration, are genetically controlled and that maize plants differ in this respect. Moreover, the magnitude of the general combining ability effects in relation to the size of specific combining ability obtained from the diallel analysis and the mean squares of the analysis of variance of generation means indicated additive heritability of nitrate-N concentration and other N-related traits in maize stalks. These findings suggest to us that a cyclic selection program in maize should be effective in modifying the level of N-related traits concentration in the stalks.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 158
    ISSN: 1573-5060
    Keywords: Zea mays ; maize ; prediction ability ; discrimination ability ; yield ; digestibility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The identification of environments suitable for selection should enable plant breeders to test reliably a larger number of genotypes with given resources. This research was undertaken to evaluate discrimination ability (DA) and prediction ability (PA) of eight environments involving two locations. Eckartsweier (Eck) 1 and Voelkenrode (Voe); 2 yer. 1984 (84) and 1985 (85); and two harvests, silage harvest (I) and later (II). It was based on dry matter yield of plant (PDMY), ear (EDMY) and stover (SDMY) and on in vitro digestible organic matter (IVDOM), neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) of stover of 12 inbred lines and their 66 diallel crosses in maize (Zea mays L.). Linear regression coefficient of the performance of genotypes in an environment on that averaged across all environments and its degree of determination were used as measures of the DA and PA of environments, respectively. In hybrids, the DA of environments differed significantly for all traits except SDMY and ADL. Environment Eck851 showed better PA (≥0.63) than other environments for PDMY, EDMY, IVDOM, NDF, and ADF. Among the 12 two-environment combinations. EckI was a better predictor for PDMY, EDMY, IVDOM and NDF (PA≥0.80). The more productive environments showed better DA and PA for PDMY and FDMY than less productive ones. For IVDOM and NDF the first harvest provided better discrimination and prediction than the second harvest. In inbred lines the DA of environments differed significantly for EDMY only. In the present study, PA and DA seemed to be functions of the environments, PA was improved by combining two environments, and some environments seemed to be suitable for preliminary selection of genotypes for such diverse traits as yield and digestibility.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 159
    ISSN: 1573-5079
    Keywords: drought ; fluorescence quenching ; gas exchange ; Helianthus annuus ; patchiness ; Phaseolus vulgaris ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Gas exchange and fluorescence measurements of attached leaves of water stressed bean, sunflower and maize plants were carried out at two light intensities (250 μmol quanta m-2s-1 and 850 μmol quanta m-2s-1). Besides the restriction of transpiration and CO2 uptake, the dissipation of excess light energy was clearly reflected in the light and dark reactions of photosynthesis under stress conditions. Bean and maize plants preferentially use non-photochemical quenching for light energy dissipation. In sunflower plants, excess light energy gave rise to photochemical quenching. Autoradiography of leaves after photosynthesis in 14CO2 demonstrated the occurrence of leaf patchiness in sunflower and maize but not in bean. The contribution of CO2 recycling within the leaves to energy dissipation was investigated by studies in 2.5% oxygen to suppress photorespiration. The participation of different energy dissipating mechanisms to quanta comsumption on agriculturally relevant species is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 160
    ISSN: 1573-5087
    Keywords: auxin-transport ; indoleacetic acid ; maize ; photoinhibition ; transport ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The uptake of IAA into excised mesocotyls of non-irradiated maize seedlings was linear up to a concentration of about 4×M and in this range there was a tight coupling between the IAA in the stele and the cortex. Prior irradiation with white light of intact seedlings unbalanced this coupling. Lateral and longitudinal transport were affected differently. In the stele, the effect of prior irradiation on longitudinal transport was multiphasic, with an initial stimulatory effect followed by a negative effect at longer prior irradiation times. The lateral transport from the stele to the cortex showed no stimulatory effect and appeared to be inhibited within at least 15 min. The effect of the prior irradiation on longitudinal transport in the stele appeared to be a high intensity effect. In contrast, the effect of the prior irradiation on the lateral transport from the stele to the cortex was saturated at much lower intensities. The data suggest that the light induced change in the lateral transport of IAA between the two tissues may be due to changes either in the number of open lateral transport channels/carriers or in the conductivity of these channels/carriers.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 161
    ISSN: 1573-5044
    Keywords: cell cycle ; DNA content ; embryogenic competence ; flow cytometry ; mitotic activity ; somatic embryogenesis ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Embryogenic competence of maize (Zea mays L.) leaf tissues was studied with regard to leaf age, distance from leaf base, mitotic activity, 2C nuclear DNA content, and the distribution of cells within the cell cycle. The highest embryogenic competence was observed in the first segment of the second innermost leaf. In a succession of 8 mm segments from the leaf base, the frequency of cells in the G0/G1 phase of the cell cycle and mitotic activity decreased with leaf age and with the distance from leaf base. No significant differences in 2C nuclear DNA content were found for leaf segments of different age and position. The mean 2C nuclear DNA content was 5.74 pg. The results suggested that the loss of embryogenic competence in mature maize leaf tissues is not related to changes in nuclear DNA content, and that the competence is not simply related to a certain distribution of cells within the cell cycle or to a certain level of mitotic activity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 162
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 33 (1993), S. 45-50 
    ISSN: 1573-5044
    Keywords: androgenetic structure quality ; anther culture ; plant regeneration ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Six media compositions and different transfer times were compared in order to improve the quality of microspore derived structures and their regeneration capacity. The production of regenerated plantlets was increased by a factor of 10 by an early transfer of anthers to medium with low sugar concentration and the use of kinetin-like growth regulators. The best transfer date was 3 weeks after initial plating, onto medium containing 25 gl−1 sucrose and 1 mg l−1 kinetin. This study demonstrates that anther transfer at an early developmental stage, before macroscopic appearance of embryo-like structures, improves embryo quality and further regeneration. This production of androgenetic structures showing normal morphological features is the first step to obtain an improvement of androgenetic plant regeneration yield.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 163
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 33 (1993), S. 237-246 
    ISSN: 1573-5044
    Keywords: embryogenic suspension culture ; Glycine max ; particle bombardment ; stable transformation ; transient expression ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A simple and inexpensive particle acceleration apparatus was designed for direct delivery of DNA to plant cells. The Particle Inflow Gun (PIG) is based on acceleration of DNA-coated tungsten particles directly in a helium steam. High levels of transient expression of theβ-glucuronidase gene were obtained following bombardment of embryogenic suspension cultures of maize and soybean, and leaf tissue of cowpea. Stable transformation of soybean and maize has also been obtained using this bombardment apparatus.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 164
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 19 (1993), S. 1613-1624 
    ISSN: 1573-1561
    Keywords: Zea mays ; corn ; cyclic hydroxamic acids ; DIMBOA ; DIBOA ; water stress ; drought ; osmotic priming ; insect resistance ; disease resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Cyclic hydroxamic acids are innate compounds associated with pest resistance in several grass species. The major cyclic hydroxamic acids of com, 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3-one (DIMBOA) and 2,4-dihydroxy-3H-1,4-benzoxazin-3-one (DIBOA), were measured in seedlings after exposure to various water stress treatments. Both DIMBOA and DIBOA were found in greater quantities in plants experiencing a water deficit stress than in nonstressed plants. The increased cyclic hydroxamic acid coincided with a reduction in seedling growth, suggesting that cyclic hydroxamic acids are stress metabolites. Plants grown under conditions that restrict growth, such as water deficit stress, contain higher cyclic hydroxamic acids, which should make them more resistant to herbivorous pests and pathogenic microorganisms.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 165
    ISSN: 1573-1561
    Keywords: Spodoptera frugiperda ; Lepidoptera ; Noctuidae ; Zea mays ; scanning electron microscopy ; cuticular lipids ; host-plant resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The cuticular lipid composition of lower and upper leaves of five genotypes of field-grown corn,Zea mays L., was determined by combined gas chromatography-mass spectrometry. Surface lipids of the upper leaves had a higher proportion ofn-alkanes (45–52%) than the lower leaves, while the lower leaves had higher percentages of fatty alcohols (12–18%) than the upper leaves. Scanning electron microscopy showed that the upper leaves of two corn genotypes, MpSWCB-4 and Cacahuacintle X's, had a smooth amorphous appearance, while the lower leaves had a dense array of wax crystals.Spodoptera frugiperda (J.E. Smith) larvae weighed more and developed more rapidly when they were reared on diet containing corn foliage from which the cuticular lipids had been removed than when they were fed untreated foliage. However, growth was not inhibited when larvae were fed diet containing the cuticular lipid extracts or individual cuticular lipid components.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 166
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 18 (1992), S. 1981-1990 
    ISSN: 1573-1561
    Keywords: Allelopathy ; ferulic acid ; amylase ; maltase ; invertase ; acid protease ; acid phosphatase ; Zea mays ; growth ; root ; shoot
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Ferulic acid was tested for its effect on the growth of root and shoot, fresh and dry weights, and hydrolytic enzyme activities of germinating maize seeds. The results showed that root growth was inhibited more than shoot growth. A significant reduction in the activities of hydrolytic enzymes was also observed, which reflects a mechanism of action for the natural growth inhibitors, which may include other phenolic compounds.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 167
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 20 (1994), S. 3335-3344 
    ISSN: 1573-1561
    Keywords: Diabrotica virgifera virgifera ; fatty acids ; linoleic acid ; oleic acid ; stearic acid ; semiochemical ; attractants ; western corn rootworm ; host location ; Coleoptera ; Chrysomelidae ; Zea mays ; kairomone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A bioassay-driven sequential fractionation scheme was used to isolate fractions of a crude dichloromethane maize seedling extract behaviorally active to larvae of the western corn rootworm,Diabrotica virgifera virgifera LeConte. (Z,Z)-9,12-Octadecadienoic (linoleic) acid, (Z)-9-octadecenoic (oleic) acid, and octadecanoic (stearic) acid were identified from a purified fraction of maize extract that was attractive to western corn rootworm larvae in choice tests with equal levels of carbon dioxide on both sides of the choice. When synthetic linoleic, oleic, and stearic acids were tested together in the amounts and proportions found in the attractive fraction (1000, 800, and 300 ng of linoleic, oleic, and stearic acids, respectively), significantly more western corn rootworm larvae were found on the side with synthetic free fatty acids plus carbon dioxide than on the side with carbon dioxide alone. Results of the choice-test bioassays were not significantly different when the synthetic blend of free fatty acids was substituted for the purified maize fraction. Neither the purified extract nor the synthetic blend was behaviorally active in preliminary single-choice experiments without carbon dioxide. Linoleic, oleic, and stearic acids were also tested individually in the choice test bioassay with carbon dioxide on both sides of the choice to determine a dose-response curve. Linoleic and oleic acid each had one dose that was significantly attractive in conjunction with carbon dioxide on both sides of the choice, but stearic acid was not active in the doses tested.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 168
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 18 (1992), S. 897-905 
    ISSN: 1573-1561
    Keywords: Pollen ; corn ; Zea mays ; teosinte ; Zea mexicana ; allelopathy ; phenylacetic acid ; phytotoxicity ; Amaranthus leucocarpus ; Echinochloa crusgalli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Phenylacetic acid (PAA), one of the phytotoxic compounds in corn (Zea mays) pollen, was identified by GC-MS and by direct comparison with a pure commercial sample of PAA. Bioassays were carried out by testing whole pollen, methylene chloride extract of the pollen, and pure PAA on germination and radical growth ofAmaranthus leucocarpus andEchinochloa crusgalli. The effect of corn pollen was compared with that ofZea mexicana (Teosinte), one of the wild relatives of cultivated maize.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 169
    Electronic Resource
    Electronic Resource
    Springer
    Nutrient cycling in agroecosystems 34 (1993), S. 9-14 
    ISSN: 1573-0867
    Keywords: Arachis hypogaea ; competitive depression ; intercropping ; K ; N beneficial effect ; N2 fixation ; 15N methodology ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Application of adequate level of K has shown to improve the competitive ability of the legume in legume/grass mixtures. However, the effect of K on the competitive ability of grain legumes in legume/cereal intercropping systems has not been adequately studied. Hence, studies were made to ascertain if the effects of K could be exploited in improving the performance of groundnut (Arachis hypogaea L.) cv. No. 45 when intercropped with maize (Zea mays L.) cv. Badra. The study was conducted at the Faculty of Agriculture, University of Ruhuna, Kamburupitiya, Sri Lanka in 1988 in basins filled with 36 kg of soil. It involved establishing maize and groundnut as monocrops and as intercrops at three K levels viz. 0, 20 and 40 mg of K kg−1 of soil. Monocrop maize and groundnut had 2 and 5 plants/basin, respectively while the intercrop had 1 maize plant and 3 groundnut plants/basin. The soil used was Red Yellow Podzolic which was tagged by incorporating15N-labelled plant material. When grown as a monocrop, K had no effect on the percent N derived from atmosphere, amount of N2 fixed, dry matter production, pod yield and total N content of groundnut. However, when intercropped with maize lack of K application affected the above parameters significantly which was overcome by improving K level. Thus, the optimum level of K for groundnut was greater when intercropped than monocropped. A significant interaction between K level and cropping system was evident with regard to N2 fixation, pod yield and total dry matter production of groundnut. Intercrop maize derived 30–35% of its N content from the associated groundnut plants which amounted to 13–22 mg N/plant. The amount of N supplied by groundnut to associated maize plant was not affected by K level. It appears that there is scope for alleviating growth depression of the legume component in legume/cereal intercropping systems by developing appropriate K fertilizer practices.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 170
    ISSN: 1572-9680
    Keywords: Cicer arietinum ; Eragrostis tef ; Pisum sativum ; tropical tree plantations ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The potential allelopathic effect ofCupressus lusitanica, Eucalyptus globulus, E. camaldulensis andE. saligna on seed germination, radicle and seedling growth was investigated with four crops:Cicer arietinum (chickpea),Zea mays (maize),Pisum sativum (pea) andEragrostis tef (teff). Aqueous leaf extracts of all the tree species significantly reduced both germination and radicle growth of the majority of the crops mostly starting from concentrations of 1% or 2.5%. The shoot and root dry weight increase of the crops was significantly reduced after 10 weeks treatment with leaf extracts. Among the four crops, chickpea and teff were most susceptible with respect to germination, and teff with respect to growth. From the overall data the leaf extracts of the four tree species can be arranged according to increasing allelopathic potential:C. lusitanica, E. globulus, E. saligna andE. camaldulensis. It is suggested that the planting ofE. camaldulensis andE. saligna in integrated land use systems should be minimized, whereas the use ofC. lusitanica andE. globulus seems less environmentally damaging in this respect.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 171
    ISSN: 1572-9680
    Keywords: Gliricidia sepium ; Zea mays ; alley cropping ; intercropping ; Sierra Leone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of spacings between hedgerows (alley widths) and the spacings of trees within hedgerows ofGliricidia sepium on growth and grain yield of maize were investigated at Senehun in southern Sierra Leone. Four between-row spacings (2, 4, 6 and 8 m) were combined with three within-row spacings (0.25, 0.50 and 1.00 m) in a split block design. Maize, at densities of 20,000, 40,000 and 53,333 plants ha−1, was established in the alleys and also as pure crops. N, P and K fertilizers were applied to all plots before pruning of the trees began. When pruning started, only the pure maize plots received fertilizer; prunings from the hedgerows were returned to the appropriate alleys in the other plots. Plots with the highest maize populations consistently gave the best yields before pruning started, but lower populations gave improved yields after pruning. Yields of maize increased with increasing alley widths before the start of pruning, after which the narrower alleys of 2 and 4 m outyielded the wider ones by almost double, probably because of the large amount of nutrients applied in prunings. Lack of light limited grain yields before the start of pruning, when there was some shading by the hedgerows. Alleys of 2–4 m wide, planted no closer than 0.50 m within rows, resulted in more than twice the yields of maize than in the 8-m alleys planted at 0.25 m within rows, once the hedgerows were well established and were being managed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 172
    ISSN: 1573-5060
    Keywords: coancestry coefficient ; genetic similarity ; maize ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary In this study, 31 elite inbred lines of maize (Zea mays L.) were analyzed with 149 clone-enzyme combinations for their respective RFLP profiles. Objectives were (1) to determine the utility of RFLPs for estimation of genetic similarties among 16 inbred lines from the Iowa Stiff Stalk Synthetic (BSSS) and among 15 inbred lines from the Lancaster Sure Crop (LSC) heterotic groups and (2) to compare genetic similarities based on molecular markers with those based on pedigree information. Coefficients of genetic similarity (GS) and coancestry (f) between pairs of lines from the same heterotic group were calculated from RFLP and pedigree data, respectively. For lines from the BSSS heterotic group, cluster analyses based on RFLP and pedigree data revealed similar associations. GS and f values were closely correlated (r=0.70) for related BSSS lines. For lines from the LSC heterotic group, considerable discrepancies existed between the GS and f values, especially for those pairs involving inbreds Va22 and Lo924. Effect of selection and/or erroneous pedigree records are discussed as possible explanations for the low correlation of GS and f values (r=0.07) for related LSC lines. RFLPs seem useful for investigation of relationships among maize inbreds, verification of pedigree records, and quantification of the degree of relatedness.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 173
    ISSN: 1573-5060
    Keywords: androgenesis ; in vitro culture ; maize ; microspores ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The capacity of the maize genotype 4c1 to regenerate microcalli and embryos from cultured microspores has been examined by comparing various cold pretreatments and culture media, using microspores and pollen at different stages of development. Viability of cultured cells was tested with FDA and their development was traced with light and fluorescence microscopy using DAPI as a nuclear dye. It was found that a pre-incubation of dissected flowers floating in a liquid nutrient medium at 8°C during 10–14 days was most successful for the induction of cell division. Among the developmental stages tested only the microspores appeared to regenerate. Subculture at 25°C in the same liquid medium, supplemented with 0.1 mg/l TIBA, gave highest rates of microspore division, i.e. up to 70% at 4 to 6 days of culture. All pathways described earlier for maize androgenic embryogenesis were observed within the 4c1 genotype. Symmetric divisions occurred in cultured microspores but most frequently asymmetric divisions lead to the formation of microcalli within 12 days of culture. In at least 60% of all dividing microspores cells were derived from the generative nucleus. Microcalli further developed either into loose or compact calli. Compact calli formed embryo-like structures.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 174
    ISSN: 1573-5060
    Keywords: diallel analysis ; host plant resistance ; Ostrinia nubilalis ; plant breeding ; Zea mays ; maize ; European corn borer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Success in breeding maize resistant to the European corn borer has been limited, with the exception of leaf feeding resistance. The inheritance of resistance to leaf, sheath-collar and ear damage in four maize germplasms and their six F1 crosses was evaluated by diallel analysis. Plants in a completely randomized design were artificially infested at the whorl, anthesis or full silk stage of plant development and were evaluated in the field for insect damage. A damage index based on size, number and location of lesions was calculated for each stage. Stowell's Evergreen (susceptible) had a mean damage index three to six times that of Maiz Amargo (resistant) at the whorl stage and the progeny plants were more resistant than the susceptible parent. Maiz Amargo and its crosses had significantly lower mean indices than Stowell's Evergreen for sheath-collar damage in Year 1 but not Year 2. Zapalote Chico, Maiz Amargo and their cross were significantly less damaged than other genotypes at the full silk stage. Heterosis values indicated an increase in resistance of crosses over the midparent average at all three stages of development. General combining ability (GCA) was highly significant for all types of damage, but specific combining ability was significant only for leaf damage. Based on estimates of GCA, Maiz Amargo was the best source of resistance to leaf and sheath-collar damage and both Zapalote Chico and Maiz Amargo would be good parents for ear damage resistance. Results suggest that resistance at different plant development stages can be combined.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 175
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 79 (1994), S. 149-161 
    ISSN: 1573-5060
    Keywords: maize ; germplasm ; cluster analysis ; landraces ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Two experiments were carried out with two objectives. First, to establish the phenetic relationships among the maize (Zea mays L.) landraces from Galicia (Northwestern Spain) maintained at the Misión Biológica de Galicia. Second, to assess the resemblance between a collection of Spanish populations (including the landraces from Galicia) and a set of US Corn Belt varieties. For the first objective 73 varieties from Galicia, along with 9 hybrid checks, were grown in 9×9 simple lattices at two locations for two years. For the second objective 131 populations from the US Corn Belt and Spain, along with 9 hybrid checks, were grown for three years in unreplicated experiments. Cluster analyses were carried out with the first principal components that accounted for a significant amount of the total variation. Four groups were found among the landraces from Galicia. The populations from Spain and America were classified as belonging to nine main groups. The replicated experiment was more accurate than the unreplicated one. However, it is concluded that an unreplicated test grown in several environments is accurate enough to detect the main groups, although some inaccuracies should be expected.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 176
    ISSN: 1573-5060
    Keywords: maize ; Zea mays ; photoinhibition ; photosynthesis ; low-temperature adaptation ; breeding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Sixty-seven inbred lines of maize were evaluated for resistance to low-temperature photoinhibition of photosynthesis, using a pulse-modulated chlorophyll fluorescence technique. The evaluation procedure was based on leaf discs, which were exposed to a high irradiance (1000 µmol/m2/s) at 7°C. The efficiency of open PSII reaction centres as a reflection of overall photosynthesis was measured before and after a photoinhibition-inducing treatment. Exposure of leaf discs to photoinhibitory condition for 2, 4, and 8 hours resulted in an efficiency reduction of 30, 53 and 83%, respectively. Testing of inbred lines showed large differences for photoinhibition susceptibility. The difference in photosynthetic efficiency between the most extreme lines after a treatment of eight hours was 39%. Resistance to photoinhibition was shown to be relevant under cool field conditions. It proved to be a trait strongly amenable to selection.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 177
    Electronic Resource
    Electronic Resource
    Springer
    Photosynthesis research 39 (1994), S. 67-73 
    ISSN: 1573-5079
    Keywords: Zea mays ; C4-photosynthesis ; decarboxylation ; NADP-ME type ; l-malate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of structural analogues of l-malate was studied on NADP-malic enzyme purified from Zea mays L. leaves. Among the compounds tested, the organic acids behaved as more potent inhibitors at pH 7.0 than at pH 8.0, suggesting that the dimeric form was more susceptible to the inhibition than the tetrameric form of the enzyme. Oxalate, ketomalonate, hydroxymalonate, malonate, oxaloacetate, tartrate, α-hydroxybutyrate, α-ketobutyrate, α-ketoglutarate and α-hydroxyglutarate exhibited linear competitive inhibition with respect to the substrate l-malate at pH 8.0. On the other hand, glyoxylate and glycolate turned out to be non-competitive inhibitors, while glycolaldehyde, succinate, fumarate, maleate and β- and γ-hydroxybutyrate had no effect on the enzyme activity, at the concentrations assayed. These results suggest that the extent of inhibition was dependent on the size of the analogues and that the presence of an 1-carboxyl group along with a 2-hydroxyl or 2-keto group was important for binding of the substrate analogue to the enzyme.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 178
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 129 (1990), S. 121-130 
    ISSN: 1573-5036
    Keywords: phosphorus ; VAM ; water soluble zinc ; Zea mays ; zinc uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Pot-grown mycorrhizal and non-mycorrhizal sweet corn were grown in a low Zn soil. All treatments received a complete nutrient solution with or without Zn. Treatments were harvested sequentially to detemine temporal mycorrhizal effects on: (a) tissue and water soluble Zn and (b) differential uptake of P and Zn. Plants grown with supplemental Zn had greater growth and Zn tissue concentration than those not receiving Zn. With no supplemental Zn, mycorrhizal treatments had greater growth and Zn concentration than non-mycorrhizal treatments. There was no indication of nutrient interaction between Zn and P. Over the range of tissue Zn found, there appeared to be no advantage to water soluble Zn analysis over total Zn in assessing plant Zn status.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 179
    ISSN: 1573-5036
    Keywords: allelopathy ; crop rotation ; nitrogen utilization ; root growth ; soil nitrate depletion ; Vigna unguiculata ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In the northern Guinea Savanna of Ghana (1984–1987) a field experiment was conducted to study the reasons for beneficial effects of rotating maize (Zea mays) and cowpea (Vigna unguiculata) on yield and N and P use of maize. The treatments included two cropping systems, maize monocropping and maize/cowpea rotation, two levels of nitrogen (0 and 80 kg N ha-1 as urea) and two levels of phosphorus application (0 and 60 kg ha-1 P as Volta phosphate rock). Yields and nutrient accumulation of maize were larger in rotation than in monocropping, independent of the N and P level. Fertilizer application (N and P) increased yields of maize in both cropping systems to the same extent. Nitrate contents of the soil after cowpea and after maize monoculture were comparable at the beginning of the cropping period. Also, potential nitrogen mineralization was only slightly larger after cowpea in the unfertilized plots. However, soil nitrate of fertilized plots was similar or even higher under monocropping than under crop rotation, especially in deeper soil layers and at the end of the cropping period. This indicates that in addition to the availability of mineral N, its use by the plants was limiting for the productivity of maize. Root length densities of maize were significant lower in monocropped maize than in maize grown in rotation. Soil physical parameters (infiltration, bulk density, aggregate stability and water capacity) showed a significant deterioration compared to a bush fallow plot, but differed only slightly between the cropping systems. Also in a pot experiment maize growth was much better in the soil from the crop rotation than from the monocropping plots, provided P was eliminated as the main growth-limiting factor. Since this effect persisted in spite of N application and optimization of soil physical properties by mixing the soil with polystyrol it is concluded that the results indicate that yield decline in maize monocropping might be due to allelopathic effects.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 180
    ISSN: 1573-5036
    Keywords: C distribution ; native soil organic matter ; rhizosphere ; root released carbon ; wheat ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Wheat and maize were grown in a growth chamber with the atmospheric CO2 continuously labelled with 14C to study the translocation of assimilated carbon to the rhizosphere. Two different N levels in soil were applied. In maize 26–34% of the net assimilated 14C was translocated below ground, while in wheat higher values (40–58%) were found. However, due to the much higher shoot production in maize the total amount of carbon translocated below ground was similar to that of wheat. At high N relatively more of the C that was translocated to the root, was released into the soil due to increased root respiration and/or root exudation and subsequent microbial utilization and respiration. The evolution rate of unlabelled CO2 from the native soil organic matter decreased after about 25 days when wheat was grown at high N as compared to low N. This negative effect of high N in soil was not observed with maize.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 181
    ISSN: 1573-5060
    Keywords: population improvement ; maize ; Zea mays ; honeycumb selection ; adaptability ; stability ; yield
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary This study was undertaken to investigate the implications of genotype x soil texture interaction on response to selection in maize. Mass honeycomb selection for yield was applied for 11 cycles from the F2 of the single cross maize hybrid F68×NE2 in a field B with silty-clay-loam soil texture. Response to selection compared to the original single cross hybrid was estimated both in absence of competition and under solid stand in the selection field B and in a nearby field A differing in soil texture (clay-loam). A strong crossover type of interaction occurred both under solid stand and in the absence of competition in the two tests the improved population outyielded the hybrid in field B in the two densities, but lagged behing the hybrid in field A. The results suggest that interaction between genotype and soil texture might affect efficiency of selection detrimentally unless provision is taken for parallel selection early in the crop improvement program in fields differing in soil texture.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 182
    ISSN: 1573-5060
    Keywords: doubled haploid ; genetic marker ; wheat ; wheat x maize crosses ; Triticum aestivum ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Wheat doubled haploid (DH) lines were produced from the F1 hybrid, Fukudo-komugi x Oligo Culm, through intergeneric crosses between wheat and maize. F2 plants and 203 DH lines were analyzed for the segregation of the eight genetic markers, namely, grain proteins, grain esterases, GA-insensitivity and glume traits. The segregation in the F2 plants fitted to the expected ratios. No deviation was observed among the DH lines, either, except for the glume pubescence. The result indicates the absence of correlation between the markers investigated and the efficiency of embryo formation in the DH lines.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 183
    ISSN: 1573-5060
    Keywords: forage maize ; Zea mays ; breeding ; nutritive value ; cell-wall digestibility ; stalk quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The current study deals with genetic improvement of the nutritive value of forage maize. In separate field trials, maize inbred lines without the brown midrib trait and derived hybrids were evaluated for stalk quality as well as some other agronomic traits. The aim was to relate the performance of lines and hybrids. Quality traits studied were the contents of ash and cell walls expressed as percentage of dry matter and the digestibilities of organic matter and cell walls (stalk-dv% and stalk-dcw%, respectively). The performance of hybrids was established in a trial at two locations with three replicates per location and the performance of lines at one location in an unreplicated trial. The range for stalk-dcw% was about 10 percentage units between hybrids and 15 percentage units between inbred lines. Stalk-dcw% had of all quality traits of hybrids the highest broad-sense heritability (h 2=0.74), and determined about 80% of the variation in stalk-dv%. The only stalk quality trait where a significant correlation was found between the mean hybrid performance and the corresponding midparent value was stalk-dcw% (r=0.70, P〈0.01). In conclusion, stalk-dcw% proved to be the only stalk quality trait worth evaluating at the inbred line level in a breeding programme aimed at producing commercial hybrid varieties of forage maize.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 184
    ISSN: 1573-5060
    Keywords: cluster analysis ; principal component analysis ; accession ; landraces ; Zea mays ; maize ; dendrogram ; variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Two multivariate techniques were used to characterize 30 maize accessions collected from three ecological zones of Bendel State, Nigeria. Differentiation of the 30 accessions into five distinct groups was achieved with the unweighted variable group method of the average linkage cluster analysis of 34 agronomic characters. Four of the taxonomic groups contained at least three accessions each, while a fifth group contained only one. The single accession contained in the fifth group was characterised by very early maturity, deeply pigmented leaves and ear husks and short statured plants. Clustering of the accessions into different phenetic groups followed substantially along geographical and traditionally trading routes. A few cases of overlapping of accessions from different geographical locations were obtained. Principal component analysis revealed that days to 50% tasseling and silking, number of nodes/plant, ear length, ear weight, leaf width, and kernel colour were the principal discriminatory characters that differentiated the accessions. Sixty-four percent of the total variation among the 34 characters were accounted for by the first five principal components while the first and second components accounted for 26 and 14 respectively.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 185
    ISSN: 1573-5060
    Keywords: resistance ; taxonomy ; maize ; maize weevil ; indigenous landraces ; phenolic acids ; life history components ; indirect selection ; Zea mays ; Sitophilus zeamais
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Accessions representing twenty eight landraces of maize were assessed for susceptibility to the maize weevil, Sitophilus zeamais in standardized resistance tests. Susceptibility parameters such as weight loss of grain, number of insect progeny produced, the Dobie index of susceptibility, and oviposition on grain were found to vary significantly by genotype, with exceptional resistance found in accessions representing the Naltel, Chapalote and Palomero landraces. As in improved genotypes, susceptibility was negatively correlated to phenolic and protein content of the variety tested but positively correlated to moisture content. A detailed analysis of the phenolics revealed the presence of diferulate which may contribute to mechanical resistance of the seed by cross-linking of cell wall hemicelluloses. A canonical discriminant analysis of the resistance data suggests that most of the five landrace groupings are significantly different. The ancient indigenous and prehistoric mestisos groupings are sources of resistant genotypes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 186
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 79 (1994), S. 13-18 
    ISSN: 1573-5060
    Keywords: Zea mays ; haploid induction ; maternal haploids ; inducer line ZMS ; maize
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Presented are the results of a two-year study of haploid maize plants in the field. The haploids were produced with the aid of inducer line ZMS. In total, 604 and 1030 haploids were obtained and studied in the first and second years, respectively. Tassels of haploid plants were found to be almost completley sterile. Fertility of ears was studied by pollinating them with the pollen from diploid inbred lines, the cross resulting in almost all of the haploid ears carrying kernels. On average 27.4 kernels per ear of haploid plant were obtained in the first year of study and 26.3 in the second. These gave rise to normal diploid plants. This property allows genotypes selected at the level of haploid plants to be involved in breeding process. Unusual plants were found among haploids, phenotypically resembling homozygous lines. It was assumed that the plants had resulted from spontaneous chromosome doubling in haploids. The results of comparative studies of progenies of unusual plants and inbred lines derived from the same synthetic population are presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 187
    ISSN: 1573-5087
    Keywords: Mitochondria ; respiration ; seed ageing ; seed storage ; temperature ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This paper reports on a study of mitochondrial activity in etiolated shoots of freshly harvested and moderately aged kernels of maize. Activity was investigated after incubation at a favourable temperature (25°C), sub-optimal temperature (13°C) and after a heat shock (46°C for 2h). Although impaired mitochondrial activity in shoots from moderately aged maize kernels was not detected at 25°C, deficiencies became evident under low temperature stress (13°C). State 3 oxygen uptake, cyanide-insensitive oxygen uptake and cytochrome oxidase activity were lower in mitochondria from these shoots at 13°C than in mitochondria from shoots of freshly harvested kernels at this temperature. After a heat shock, cyanide-insensitive oxygen uptake was higher, and cytochrome oxidase activity lower, in shoots of aged kernels than in shoots of fresh kernels. No significant differences in ADP: O ratio or succinate dehydrogenase activity occurred between mitochondria from shoots of the two seed lots in any of the temperature treatments.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 188
    Electronic Resource
    Electronic Resource
    Springer
    Plant growth regulation 14 (1994), S. 235-242 
    ISSN: 1573-5087
    Keywords: auxin transport ; calcium ; gravitropism ; root cap ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract There is evidence that the cap is the initial site of lateral auxin redistribution during the gravitropic response of roots. We tested this further by comparing asymmetric auxin redistribution across the tips of gravistimulated intact roots, decapped roots, isolated root caps and isolated apical sections taken from decapped roots. Gravistimulation caused asymmetric (downward) auxin movement across the tips of intact roots and isolated root caps but not across the tips of decapped roots or across isolated apical root segments. Naphthylphthalamic acid and pyrenoylbenzoic acid, inhibitors of polar auxin transport, inhibited asymmetric auxin redistribution across gravistimulated isolated root caps and across the tips of gravistimulated intact roots. For intact roots there was a positive correlation between the extent of inhibition of assymmetric auxin redistribution by polar auxin transport inhibitors and the extent of inhibition of asymmetric calcium chelating agent, ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid, also caused parallel inhibition of asymmetric auxin redistribution and gravitropic curvature and this effect was reversed by subsequent treatment with calcium. The results support the hypothesis that the cap is a site of early development of auxin asymmetry in gravistimulated roots and that calcium plays an important role in the development of lateral auxin redistribution.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 189
    ISSN: 1573-5044
    Keywords: DNA delivery ; electroporation electrolyte ; heat shock ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Electroporation was used for the delivery and subsequent expression of GUS and anthocyanin reporter genes into intact maize immature embryos. The optimal conditions consisted of culturing immature embryos for 4 days on N6 1-100-25-Ag medium prior to electroporation (375 V/cm; 960 µF capacitance) in EPR buffer containing DNA and 0.07 M sodium glutamate at room temperature (22°C) after a 10 min heat shock at 37°C. Under these conditions, over 40 spots of GUS transient activity were observed per immature embryo. Transient gene expression after electroporation was further demonstrated using an anthocyanin construct, which is specific for expression in plant cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 190
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 16 (1990), S. 3425-3439 
    ISSN: 1573-1561
    Keywords: Coleoptera ; Chrysomelidae ; Diabrotica virgifera virgifera ; semiochemical ; kairomone ; attractants ; repellents ; Zea mays ; western corn rootworm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Dichloromethane extracts of germinating corn are significantly attractive to western corn rootworm larvae in choice tests with equal levels of carbon dioxide present on both sides of the choice. Two fractions that are significantly attractive and two fractions that are significantly repellent to larvae were isolated from these extracts of germinating corn by gas chromatography and silica gel chromatography. In a separate set of experiments, Porapak N was used to collect headspace volatiles from germinating corn; significantly more larvae were attracted to aliquots of these extracts in singlechoice tests without added carbon dioxide present than to solvent controls.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 191
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 18 (1992), S. 931-944 
    ISSN: 1573-1561
    Keywords: Diabrotica virgifera virgifera ; 6-methoxy-2-benzoxazolinone ; hydroxamic acids ; semiochemical ; attractants ; western corn rootworm ; host location ; Coleoptera ; Chrysomelidae ; Zea mays ; kairomone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A bioassay-driven sequential fractionation scheme was used to isolate all portions of a crude dichloromethane corn seedling extract behaviorally active to larvae of the western corn rootworm,Diabrotica virgifera virgifera LeConte. 6-Methoxy-2-benzoxazolinone (MBOA) was identified as one of the most important components of an attractive crude corn extract. MBOA was found on or in the intact root tissues by injecting an extract of undamaged roots onto an HPLC immediately after extraction. MBOA was demonstrated to be volatile and functions as a semiochemical in conjunction with carbon dioxide in host location by western corn rootworm larvae, which are oligophagous on the roots of maize and several other species of grasses. Because MBOA occurs almost exclusively in maize and other grasses, it offers a simple way for the larvae to distinguish possible hosts from non-hosts. MBOA has previously been reported as a chemical defense against other insect species. This is the first report in grasses of a secondary compound that is toxic or a deterrent to nonadapted insect herbivores but that is used as a semiochemical in host location by a specialist insect species.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 192
    ISSN: 1573-1561
    Keywords: Elicitor ; corn ; Zea mays ; caterpillar regurgitate ; plant volatiles ; synomones ; semiochemicals ; parasitoids ; Cotesia marginiventris ; Microplitis croceipes ; host searching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Regurgitate of corn-fed beet armyworm (BAW) caterpillars,Spodoptera exigua, when applied to damaged sites of corn (Zea mays) seedlings, causes the release of relatively large amounts of terpenes by the seedlings several hours later. This plant response could be induced by merely placing the cut stem of seedlings in a solution of BAW regurgitate for 12 hr, a response that could not be induced by placing seedlings in water only. Regurgitate of BAW fed various diets, including a minimal diet of filter paper, were all active. However, seedlings placed in corn leaf juice, BAW hemolymph, or BAW feces extract released significantly smaller amounts of terpenes than did seedlings placed in BAW regurgitate. These results indicate that the active components are present in relatively large concentrations in regurgitate and that they are not related to the food source. Furthermore, regurgitate from several other species of caterpillars (Spodoptera frugiperda, Helicoverpa zea,Trichoplusia ni, andAnticarsia gemmatalis) as well as from the grasshopperSchistocerca americana induced the release of significant amounts of terpenes in corn seedlings. The release of these volatiles, therefore, appears to be a general response to attack by phytophagous insects. The terpene-releasing corn seedlings were highly attractive to the generalist parasitoidCotesia marginiventris and to the specialized parasitoidMicroplitis croceipes. This study confirms a systemic herbivore-elicited release of terpenes in corn. It is proposed that such chemicals serve multifunctional purposes that directly and indirectly protect plants against herbivorous arthropods and pathogens.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 193
    ISSN: 1573-8248
    Keywords: Beauveria bassiana ; Ostrinia nubilalis ; endophytic relationship ; biological control ; insect pathology ; Zea mays ; Beauveria bassiana ; Ostrinia nubilalis ; lutte biologique ; relation endophyte ; pathologie de l'insecte ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Résumé Le champignon entomopathogène,Beauveria bassiana (Balsamo) Vuillemin a été épandu sur maïs, au stade cornet (V7) par application foliaire d'une formulation granulée de grits de maïs contenant des conidies ou par injection d'une suspension de conidies. Toutes les plantes ont été infestées à l'aide de larves de la Pyrale du maïs,Ostrinia nubilalis, au stade V7 (cornet), V12 (fin de stade cornet), ou V17 (apparition de la panicule). Les plantes infestées au stade cornet et à la fin du stade cornet ont eu significativement plus de chenilles de Pyrale en train de miner que les plantes infestées au stade début de panicule mâle. Le pourcentage de plantes infestées parB. bassiana n'était pas significativement différent entre ces 3 stades phénologiques. Au fur et à mesure que les plantes se développaient,B. bassiana était isolé de différentes parties de la plante, la moelle étant plus souvent infestée que les ligules. Les applications foliaires deB. bassiana ont entraîné la destruction immédiate de la pyrale chez les plantes infestées au stade cornet. La baisse de l'efficacité deB. bassiana aux stades intermédiaires par comparaison avec son efficacité au moment de la récolte est discutée.
    Notes: Abstract The entomopathogenic fungus,Beauveria bassiana (Balsamo) Vuillemin, was applied to whorl-stage (V7) corn,Zea mays L., by foliar application of a granular formulation of corn grits containing conidia or by injection of a conidial suspension. All plants were infested with European corn borer larvae,Ostrinia nubilalis (Hübner), at the V7 (whorl), V12 (late-whorl), or V17 (pretassel) stage of plant development. Plants infested at whorl and late-whorl stages had significantly more European corn borer tunneling than did plants infested at the pretassel stage. The percentage of plants colonized byB. bassiana did not differ significantly among the whorl, late-whorl, and pretassel stages. As the plants matured,B. bassiana was isolated from different plant areas, with the pith more frequently colonized than the leaf collars. Foliar application ofB. bassiana provided immediate suppression ofO. nubilalis in those plants infested at whorl stage. The reduced efficacy ofB. bassiana at the intermediate plant stages relative to efficacy at harvest is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...