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  • 1
    Electronic Resource
    Electronic Resource
    Allelopathic activity in wheat-conventional and wheat-no-till soils: Development of soil extract bioassays (1992)
    Springer
    Journal of chemical ecology 18 (1992), S. 2191-2221 
    Details
    ISSN: 1573-1561
    Keywords: Cover crops ; wheat ; Triticum aestivum ; soybean ; Glycine max ; soil extracts ; germination bioassays ; phenolic acids ; hydroxamic acids ; allelopathy ; slope analysis ; ivy-leaved morning glory ; Ipomoea hederacea ; crimson clover ; Trifolium incarnalum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The primary objective of this research was to determine if soil extracts could be used directly in bioassays for the detection of allelopathic activity. Here we describe: (1) a way to estimate levels of allelopathic compounds in soil; (2) how pH, solute potential, and/or ion content of extracts may modify the action of allelopathic compounds on germination and radicle and hypocotyl length of crimson clover (Trifolium incarnatum L.) and ivyleaved morning glory (Ipomoea hederacea L. Jacquin.); and (3) how biological activity of soil extracts may be determined. A water-autoclave extraction procedure was chosen over the immediate-water and 5-hr EDTA extraction procedures, because the autoclave procedure was effective in extracting solution and reversibly bound ferulic acid as well as phenolic acids from wheat debris. The resulting soil extracts were used directly in germination bioassays. A mixture of phenolic acids similar to that obtained from wheat-no-till soils did not affect germination of clover or morning glory and radicle and hypocotyl length of morning glory. The mixture did, however, reduce radicle and hypocotyl length of clover. Individual phenolic acids also did not inhibit germination, but did reduce radicle and hypocotyl length of both species. 6-MBOA (6-methoxy-2,3-benzoxazolinone), a conversion product of 2-o-glucosyl-7-methoxy-1,4-benzoxazin-3-one, a hydroxamic acid in living wheat plants, inhibited germination and radicle and hypocotyl length of clover and morning glory. 6-MBOA, however, was not detected in wheat debris, stubble, or soil extracts. Total phenolic acids (FC) in extracts were determined with Folin and Ciocalteu's phenol reagent. Levels of FC in wheat-conventionaltill soil extracts were not related to germination or radicle and hypocotyl length of either species. Levels of FC in wheat-no-till soil extracts were also not related to germination of clover or morning glory, but were inversely related to radicle and hypocotyl length of clover and morning glory. FC values, solute potential, and acidity of wheat-no-till soil extracts appeared to be independent (additive) in action on clover radicle and hypocotyl length. Radicle and hypocotyl length of clover was inversely related to increasing FC and solute potential and directly related to decreasing acidity. Biological activity of extracts was determined best from slopes of radicle and hypocotyl length obtained from bioassays of extract dilutions. Thus, data derived from the water-autoclave extraction procedure, FC analysis, and slope analysis for extract activity in conjunction with data on extract pH and solute potential can be used to estimate allelopathic activity of wheat-no-till soils
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00984946
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  • 2
    Electronic Resource
    Electronic Resource
    Nucleotide sequence of a cDNA coding for the barley seed protein CMa: an inhibitor of insect α-amylase (1992)
    Springer
    Plant molecular biology 18 (1992), S. 423-427 
    Details
    ISSN: 1573-5028
    Keywords: Hordeum vulgare L. ; CM protein ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The primary structure of the insect α-amylase inhibitor CMa of barley seeds was deduced from a full-length cDNA clone pc43F6. Analysis of RNA from barley endosperm shows high levels 15 and 20 days after flowering. The cDNA predicts an amino acid sequence of 119 residues preceded by a signal peptide of 25 amino acids. Ala and Leu account for 55% of the signal peptide. CMa is 60–85% identical with α-amylase inhibitors of wheat, but shows less than 50% identity to trypsin inhibitors of barley and wheat. The 10 Cys residues are located in identical positions compared to the cereal inhibitor family with a Pro-X-Cys motif present in all.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00034972
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  • 3
    Electronic Resource
    Electronic Resource
    Analysis of the gibberellin-responsive promoter of a cathepsin B-like gene from wheat (1992)
    Springer
    Plant molecular biology 20 (1992), S. 849-856 
    Details
    ISSN: 1573-5028
    Keywords: GA regulation ; thiol-protease promoter ; wheat ; aleurone ; particle gun
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A wheat gene (A121) encoding a protein with sequence similarity to mammalian cathepsin B is regulated by gibberellic acid (GA) in aleurone layers of germinating grains. To analyse the mechanism of A121 regulation, its promoter was fused to the β-glucuronidase reporter gene (GUS) and introduced by micro-projectile bombardment into aleurone layers of oat. With 2.3 kb of promoter sequence, the GUS expression was enhanced by GA treatment. This effect was reversed by abscisic acid (ABA). This result showed for A121, like the α-amylase genes, that the regulation by GA and ABA was at the level of transcription. The GA responsiveness of the promoter was retained with as little as 276 bp of promoter sequence. Sequence comparison with a GA responsive promoter of an α-amylase gene identified the conserved element GCAACGGCAACGATGG which is required intact for full expression of both promoters. However, there was no identifiable similarity in the cathepsin-like promoter with the GA-responsive element of α-amylase promoters with the consensus sequence TAACAAA, suggesting that GA affects more than one mechanism of transcriptional control.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00027156
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  • 4
    Electronic Resource
    Electronic Resource
    Sequence analysis of WIS-2-1A, a retrotransposon-like element from wheat (1992)
    Springer
    Plant molecular biology 20 (1992), S. 991-995 
    Details
    ISSN: 1573-5028
    Keywords: retrotransposon-like element ; sequence analysis ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract WIS-2-1A, a 8624 bp insertion in the Glu-1A-2 locus of chromosome 1A of wheat, consists of two 1755 bp long terminal repeats enclosing a 5114 bp internal region. No long open reading frames could be found, but inspection of the predicted amino acid sequence showed regions with homology to retrotransposon structures, including a methionine tRNA initiator binding site, a nucleotide binding domain, a protease, an integrase and a polymerase. DNA replication errors have resulted in frame-shifts in the protein coding region, suggesting that retrotransposition of WIS-2-1A, if it occurs, must be mediated by trans-acting factors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00027169
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  • 5
    Electronic Resource
    Electronic Resource
    Isolation and characterization of a cDNA clone encoding the TATA box-binding protein (TFIID) from wheat (1992)
    Springer
    Plant molecular biology 19 (1992), S. 867-872 
    Details
    ISSN: 1573-5028
    Keywords: TATA box ; TFIID ; transcription factor ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We isolated a complementary DNA (cDNA) encoding the TATA-binding factor ‘TFIID’ from a wheat seedling cDNA library. The wheat TFIID transcript of 1.2 kb poly(A)+ RNA was expressed at a low level early in germination, but gradually increased as the seedlings developed. In vitro binding experiments showed that the bacterially expressed wheat TFIID protein could specifically bind to the TATA boxes of the cauliflower mosaic virus (CaMV) 35S, wheat histone H3 and adenovirus major late genes with different affinity. A comparison with Arabidopsis TFIID showed the presence of a plant-specific region consisting of 13 amino acids at the divergent amino terminus and a conserved region (182 amino acids) at the carboxy terminus longer than that observed in yeasts (180 amino acids) and animals (181 amino acids).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00027083
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  • 6
    Electronic Resource
    Electronic Resource
    Nucleotide sequence of the internal transcribed spacer region of rDNA in diploid wheat,Triticum speltoides L. (Tausch) Gren. ex Richter (Gramineae) (1992)
    Springer
    Plant molecular biology 20 (1992), S. 157-158 
    Details
    ISSN: 1573-5028
    Keywords: rRNA ; PCR ; ITS ; DNA sequence ; nucleotide ; Triticum speltoides ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00029158
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  • 7
    Electronic Resource
    Electronic Resource
    Nucleotide sequence of the internal transcribed spacer region of rDNA in wheat,Triticum aestivum L. (Gramineae) (1992)
    Springer
    Plant molecular biology 20 (1992), S. 159-160 
    Details
    ISSN: 1573-5028
    Keywords: rRNA ; PCR ; ITS ; DNA sequence ; nucleotide ; Triticum aestivum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00029159
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  • 8
    Electronic Resource
    Electronic Resource
    Sequence and organization of a 7.2 kb region of wheat mitochondrial DNA containing the large subunit (26S) rRNA gene (1992)
    Springer
    Plant molecular biology 20 (1992), S. 347-352 
    Details
    ISSN: 1573-5028
    Keywords: mitochondrial DNA ; repeated sequences ; ribosomal RNA ; t-elements ; Triticum aestivum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We report the sequence of a 7.2 kilobase pair DNA fragment containing a copy of the wheat mitochondrial gene (rrn26) that encodes the mitochondrial large-subunit ribosomal RNA (26S rRNA). The mature 26S rRNA was determined by direct RNA sequencing to be 3467 nucleotides long, and to share a 5′-terminal pentanucleotide (5′-AUCAU), thought to be important in post-transcriptional processing, with the wheat mitochondrial small-subunit (18S) rRNA. Two other prominent features of the sequence were noted. First, upstream of rrn26 are located two tandem copies of a 70 base pair element containing a putative mitochondrial promoter motif (TCGTATAAAAA). Second, downstream of rrn26 is a sequence element that, if transcribed, would produce and RNA with a secondary structure resembling that of tRNAs but differing sufficiently from the latter structure to preclude any transcript from functioning normally in translation. These upstream and downstream sequence elements may play a role in the expression of rrn26 in wheat mitochondria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00014506
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  • 9
    Electronic Resource
    Electronic Resource
    Dynamical behavior of psb gene transcripts in greening wheat seedlings. I. Time course of accumulation of the psbA through psbN gene transcripts during light-induced greening (1992)
    Springer
    Plant molecular biology 20 (1992), S. 695-704 
    Details
    ISSN: 1573-5028
    Keywords: chloroplast ; gene expression ; photosystem 2 ; transcription ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The time course of the accumulation of the transcripts from 13 psb genes encoding a major part of the proteins composing photosystem II during light-induced greening of dark-grown wheat seedlings was examined focusing on early stages of plastid development (0.5 h through 72 h). The 13 genes can be divided into three groups. (1) The psbA gene is transcribed as a single transcript of 1.3 kb in the dark-grown seedlings, but its level increases 5- to 7-fold in response to light due to selective increase in RNA stability as well as in transcription activity. (2) The psbE-F-L-J operon, psbM and psbN genes are transcribed as a single transcript of 1.1 kb, two transcripts of 0.5 and 0.7 kb and a single transcript of 0.3 kb, respectively, in the dark-grown seedlings. The levels of accumulation of every transcript remain unchanged or rather decrease during plastid development under illumination. (3) The psbK-I-D-C gene cluster and psbB-H operon exhibit fairly complicated northern hybridization patterns during the greening process. When a psbC or psbD gene probe was used for northern hybridization, five transcripts differing in length were detected in the etioplasts from 5-day old dark-grown seedlings. After 2 h illumination, two new transcripts of different length appeared. Light induction of new transcripts was also observed in the psbB-H operon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00046454
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  • 10
    Electronic Resource
    Electronic Resource
    Adaptive foraging by predators as a cause of predator-prey cycles (1992)
    Springer
    Evolutionary ecology 6 (1992), S. 56-72 
    Details
    ISSN: 1573-8477
    Keywords: dynamics of adaptation ; optimal foraging ; predator-prey cycles ; stability ; type-2 functional response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary When foraging has costs, it is generally adaptive for foragers to adjust their foraging effort in response to changes in the population density of their food. If effort decreases in response to increased food density, this can result in a ‘type-2’ functional response; intake rate increases in a negatively accelerated manner as prey density increases. Unlike other mechanisms for type-2 responses, adaptive foraging usually involves a timelag, because foraging behaviours do not often change instantaneously with changes in food density or risks. This paper investigates predator-prey models in which there are explicit dynamics for the rate of adaptive change. Models appropriate to both behavioural and evolutionary change are considered. Both types of change can produce cycles under similar circumstances, but under some evolutionary models there is not sufficient genetic variability for evolutionary change to produce cycles. If there is sufficient variability, the remaining conditions required for cycles are surprisingly insensitive to the nature of the adaptive process. A predator population that approaches the optimum foraging strategy very slowly usually produces cycles under similar conditions as does a very rapidly adapting population.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02285334
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  • 11
    Electronic Resource
    Electronic Resource
    Effects of pre-storage conditions on storage of in vitro cultures of Nephrolepis exaltata (L.) Schott and Cordyline fruticosa (L.) A. Chev. (1992)
    Springer
    Plant cell, tissue and organ culture 28 (1992), S. 167-174 
    Details
    ISSN: 1573-5044
    Keywords: dark ; in vitro storage ; light ; stability ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In vitro cultures of Nephrolepis exaltata and Cordyline fruticosa were stored at 5°, 9° or 13°C, at a low irradiance (3–5 μmol m−2 s−1) or in darkness. Prior to storage the cultures were subjected to 18°, 21°, 24° or 27°C and 15, 30 or 45 μmol m−2 s−1 in a factorial combination. The optimal storage conditions for Nephrolepis were 9°C in complete darkness. These cultures were still transferable to a peat/perlite mixture at the end of the experimental period of 36 months. The optimal storage conditions for Cordyline were 13°C and a low light level (±3–5 μmol m-2 s-1). When the pre-storage conditions were normal growth room conditions (24°C and 30 μmol m-2 s-1), in vitro cultures could be stored for 18 months. With the most favourable pre-storage treatment (18°C and 15 μmol m-2 s-1) some cultures still had green shoots after 36 months of storage, but did not survive transfer to peat/perlite. Pre-conditioning before storage was most favourable for Nephrolepis, and not that important, but still favourable, for Cordyline. There was an interaction between pre-storage temperature and pre-storage irradiance. For both species a high irradiance level was less favourable than a low irradiance level when combined with high growth room temperatures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00055513
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  • 12
    Electronic Resource
    Electronic Resource
    Predictability of streamflow and particulate organic matter concentration as indicators of stability in prairie streams (1992)
    Springer
    Hydrobiologia 242 (1992), S. 7-18 
    Details
    ISSN: 1573-5117
    Keywords: POM ; prairie streams ; predictability ; stability ; stream flow
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Predictability of stream discharge and particulate organic matter (POM) in the water column was estimated, using Colwell's indices of constancy and contingency, for 6 Texas prairie streams (1 each of 2nd, 3rd, and 4th order with intermittent or perennial discharge). Stream discharge in these 6 prairie streams varied between 0 and 36000 1 s−1, depending on the stream and season. Predictability (P) of discharge in these streams ranged from 0.45 to 0.62, within the range of values expected for North American streams. Predictability of stream discharge was not significantly different between streams. Particulate organic matter concentrations in these prairie streams are relatively low, ranging from 0.25 to 4.00 mg AFDM 1−1. Predictability of POM concentration in these streams was high, ranging from 0.75 to 0.85, and was largely the result of constancy of POM concentrations. Within the different POM size classes, Fine POM (FPOM) had the highest predictability (P = 0.89−0.96). In spite of relatively unpredictable stream discharge, POM remained fairly constant providing a measure of habitat predictability and stability.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00017639
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  • 13
    Electronic Resource
    Electronic Resource
    Foliar chemicals of wheat and related grasses influencing oviposition by Hessian fly,Mayetiola destructor (Say) (Diptera: Cecidomyiidae) (1992)
    Springer
    Journal of chemical ecology 18 (1992), S. 1965-1980 
    Details
    ISSN: 1573-1561
    Keywords: Hessian fly ; Mayetiola destructor ; Diptera ; Cecidomyiidae ; oviposition stimulants ; wheat ; rye ; barley ; oat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract More than twice the number of mated female Hessian flies,Mayetiola destructor (Say) entered a zone within 1 cm of a paper strip treated with one plant equivalent (PE) of a chloroform extract of wheat foliar waxes compared to a strip treated with solvent only; females also stayed six times longer and laid 10 times more eggs on the strip treated with the wheat extract. Column chromatographic fractionation of the wheat extract and application of these fractions onto filter paper strips showed four fractions elicited significant numbers of eggs to be laid. Single, binary, and tertiary combinations of three of these fractions (two of the four fractions apparently contained similar compounds) were tested. The greatest numbers of eggs were laid on strips treated with the tertiary combination or the binary combination conaining the two most active fractions (3 and 6); three times the number of eggs were laid on strips treated with this binary combination than the sum of eggs laid on strips treated with these two fractions separately. A comparison of grasses and their extracts showed female Hessian flies laid greater numbers of eggs on wheat or rye than on barley or oat. Fractionated barley and oat extracts were tested for activity as for wheat, and a similar pattern was observed, i.e., the greatest numbers of eggs were laid on fractions 3 and 6. Dose-response tests, using these two fractions of wheat, barley, or oat showed the same threshold of activity for fraction 3 for all three extracts, i.e., 2 PE. In contrast, fraction 6 of wheat was active at the lowest dosage tested, 0.25 PE, while the same fraction of either barley or oat was not active until tested at a dosage of 2 PE. It appears that (at least) two chemicals in the foliar waxes of these grasses influence ovipositional behavior of female Hessian flies. Furthermore, given the similar foliar chemistry of these grasses and the strong synergistic interaction between fractions 3 and 6 shown for wheat extract, it is likely that the ovipositional preferences exhibited by female Hessian flies towards these grasses may be explained by quantitative differences in the amount(s) of the active chemical(s) in their respective fraction 6 (most polar fraction tested).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00981920
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  • 14
    Electronic Resource
    Electronic Resource
    Hydroxamic acid glucosides in honeydew of aphids feeding on wheat (1992)
    Springer
    Journal of chemical ecology 18 (1992), S. 841-846 
    Details
    ISSN: 1573-1561
    Keywords: Rhopalosiphum padi ; Homoptera ; Aphididae ; wheat ; maize ; DIMBOA ; hydroxamic acids ; aphid honeydew
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract DIMBOA glucoside (2-O-/gb-D-glucopyranosyl-4-hydroxy-7-meth-oxy-1,4-benzoxazin-3-one), the main hydroxamic acid (Hx) in intact wheat plants, was detected in the honey dew ofRhopalosiphum padi feeding on seedlings of six wheat cultivars that differed in their concentration of Hx, suggesting that the chemical circulates in the phloem. Neither the aglucone (DIMBOA) nor its main breakdown product were found in any of the honeydew samples. Honey dew production by aphids caged on seedlings of the wheat cultivars and DIMBOA glucoside concentrations in the honeydew followed biphasic curves when plotted against Hx concentration, suggesting passive ingestion of the chemical from the phloem at low Hx concentrations and limited ingestion due to feeding deterrency by Hx in mesophyll cells at high Hx concentrations. The presence of plant toxins such as Hx glucosides in the phloem sap, the main ingesta of aphids, and in the mesophyll cells, has major implications for plant defense, through a feeding deterrent effect during stylet penetration, and deterrency (antixenosis) along with antibiosis during feeding.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00988324
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  • 15
    Electronic Resource
    Electronic Resource
    Reconsidering the green revolution: Diversity and stability in cradle areas of crop domestication (1992)
    Springer
    Human ecology 20 (1992), S. 145-167 
    Details
    ISSN: 1572-9915
    Keywords: agriculture ; development ; diversity ; stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Ethnic Sciences
    Notes: Abstract This paper reconsiders two widely held hypotheses about the effects of the green revolution, that it led to biological simplification and instability. The hypothesis of biological simplification (genetic erosion) is tested with evidence from Andean agriculture, where farmers maintain a significant degree of crop diversity even as they adopt modern crop varieties. The hypothesis of increased instability is tested with evidence from Asia where wheat and rice yields show no general pattern of increased instability. Neither of these hypotheses is confirmed. The conventional wisdom about the green revolution should be reconsidered with emphasis on resilience and variation in modernizing farming systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00889077
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  • 16
    Electronic Resource
    Electronic Resource
    Spatial and temporal trends in stream macroinvertebrate communities: the influence of catchment disturbance (1992)
    Springer
    Hydrobiologia 241 (1992), S. 173-194 
    Details
    ISSN: 1573-5117
    Keywords: disturbance ; recovery ; fire ; streams ; stability ; macroinvertebrates ; watershed
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Macroinvertebrate communities of five headwater streams in catchments disturbed by wildfire were compared with five similar streams with no catchment disturbance. Over the five years of observation, communities in disturbed streams were more similar to one another than they were to reference streams. Communities in disturbed streams exhibited more year-to-year variation than reference streams, although some indication of decreasing variation was evident through time, and species richness was greater in reference streams than disturbed streams. No increasing trend in richness over time was observed in disturbed streams. Stability of the relative abundance structure and persistence of dominant taxa through time may be characteristic of temperate streams over moderate time intervals. Local effects of catchment-wide disturbance have persistent effects that alter these trends.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00028640
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  • 17
    Electronic Resource
    Electronic Resource
    Somatic embryogenesis and plant regeneration from protoplasts isolated from embryogenic cell suspensions of wheat (Triticum aestivum L.) (1992)
    Springer
    Plant cell, tissue and organ culture 28 (1992), S. 79-85 
    Details
    ISSN: 1573-5044
    Keywords: plant regeneration ; protoplast ; somatic embryo ; suspension ; Triticum aestivum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We describe the early formation of somatic embryos followed by plant regeneration from protoplasts isolated from an embryogenic wheat cell suspension, which was initiated from small granular (0.2 to 1 mm in size) embryogenic calli. These granular calli formed embryogenic cell suspensions within 20 days in liquid culture, and were selected gradually from young inflorescence-derived nodular embryogenic calli of the winter wheat cv. Kehong 1041. The division frequency of protoplasts was 11 to 16%, and the frequency of differentiation into plants was about 0.001% (number of plants formed divided by the total number of protoplasts plated). About 20% of somatic embryos present in the culture formed directly from protoplast-derived cells within 15 days of cultures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00039918
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  • 18
    Electronic Resource
    Electronic Resource
    Functional properties of ficoll and their influence on anther culture responses of wheat (1992)
    Springer
    Plant cell, tissue and organ culture 30 (1992), S. 77-83 
    Details
    ISSN: 1573-5044
    Keywords: anther culture ; ficoll ; liquid medium ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of ficoll in liquid culture media have been contradictory in previous reports. The objective of this study was to determine the functional properties of ficoll in potato 4 (P4) liquid induction medium and their influence on anther culture responses of wheat. Ficoll addition significantly (p≤0.01) reduced callus production from the anthers of spring wheat cv. Pavon 76. The reduction was directly related to the concentration of ficoll added within the range of 50 to 200 g l-1 medium. Although the addition of ficoll significantly (p≤0.01) increased the percentage of regenerable calli and the ratio of green vs. albino plants, the final yield of green plants per 100 anthers was significantly lower. Consistent results also were obtained with four other spring wheat genotypes (Chris, Butte 86, WA 6916, and Edwall). Ficoll concentration affected the density, viscosity, and osmolality of the liquid media. The higher medium density caused by ficoll addition increased the percentage of floating calli, as well as the percentage of regenerable calli and the ratio of green vs. albino plants. However, the increased medium viscosity by ficoll addition significantly (p≤0.01) reduced callus production. Ficoll addition also increased medium osmolality, which affected callus production by interacting with the sugar concentration of the induction media. Using response functions, the estimated maltose concentration for maximum callus production was 105 g l-1 for the standard P4 media, compared with 68 g l-1 for the ficoll-containing P4 media. These results clearly demonstrate that ficoll addition to the liquid P4 induction medium containing high sucrose concentration (90 g l-1) is deleterious to the maximum production of green plants from wheat anther culture.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00040004
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