ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Artikel  (174)
  • Analytical Chemistry and Spectroscopy
  • Biochemistry and Biotechnology
  • Brassica napus
  • General Chemistry
  • Inorganic Chemistry
  • Life and Medical Sciences
  • Springer  (174)
  • 1990-1994  (112)
  • 1985-1989  (58)
  • 1955-1959  (4)
Sammlung
  • Artikel  (174)
Schlagwörter
Verlag/Herausgeber
Erscheinungszeitraum
Jahr
  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 19 (1991), S. 323-327 
    ISSN: 1432-0983
    Schlagwort(e): Brassica napus ; CMS ; ‘Polima’ cytoplasm ; Mitochondrial transcription
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary We report here on RFLP and Northern blot analyses of the ‘Polima’ CMS-System in Brassica napus. Mitochondrial (mt)DNA and plastid (pt)DNA data indicate that the restorer, as well as the sterile and restored plants, possess a pol cytoplasm but that the restores has no Brassica mt-plasmid. An additional substoichiometric 3.3 kb EcoRI ptDNA fragment is present in the restorer. The transcription patterns of 12 mitochondrial-encoded genes of the pol cytoplasm have been determined for male-sterile and restored plants. Transcription patterns of the atp6 gene are correlated with the nuclear background. Restorer and restored plants exhibit two additional transcripts not detectable in sterile plants.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Sexual plant reproduction 2 (1989), S. 15-17 
    ISSN: 1432-2145
    Schlagwort(e): Brassica napus ; Spontaneous androgenesis ; Erucic acid content ; Flower colour
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Seeds of androgenetic origin were obtained among the F1 progenies of two crosses between resynthesized and cultivated forms of Brassica napus. The high-erucic, white-flowered, resynthesized line No7076 acted as the female, and the zero-erucic, yellow-flowered, cultivars ‘Topas’ and ‘Puma’, as males. No androgenetic seeds were obtained in the reciprocal crosses. Resynthesized rape could thus be of potential use for the production of androgenetic plants. Of special interest is the high frequency (21%) of spontaneous androgenesis observed in one of the two crosses. One plant, determined from erucic acid content and flower colour analysis as androgenetic, had a diploid chromosome number. Further knowledge about the genetic control of spontaneous androgenesis in the present material and the origin of the cytoplasm in androgenetic plants are required in order to exploit this phenomenon in practical plant breeding.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Sexual plant reproduction 4 (1991), S. 22-27 
    ISSN: 1432-2145
    Schlagwort(e): Brassica napus ; Cytoplasmic male sterility ; Microsporogenesis ; Temperature ; Transmission electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Under an intermediate temperature regime (23° C/18° C; day/night), microsporogenesis in stamens of the ogu cytoplasmic male-sterile (CMS) line of Brassica napus terminated by the tetrad stage, although in some cases degeneration of the sporogenous tissue occurred prior to meiosis. In most cases the tetrads were collapsed and bounded by a sparse exine, but contained many organelles. Also, the tapetum in CMS anthers was abnormal and often highly vacuolated by the tetrad stage. Under low temperature conditions (18° C/15° C; day/night), neither microsporogenous nor tapetal tissues were observed. In the normal stamens, no differences were observed under different temperature regimes. In conjunction with the adjoining paper, this study demonstrates that temperature conditions strongly affect the cytological processes associated with microsporogenesis in the CMS anthers.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Sexual plant reproduction 4 (1991), S. 48-55 
    ISSN: 1432-2145
    Schlagwort(e): Brassica napus ; Colchicine ; Cytoskeleton ; Microspore-embryogenesis ; Pollen
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary An attempt has been made to manipulate the cytological processes regulating the switch from gametophytic to sporophytic development induced by culturing the microspores of higher plants. Previous studies have indicated that sporophytic development, which leads to the formation of haploid embryos, normally follows the symmetrical division of the microspore rather than the asymmetric mitosis characteristic of normal development. To determine whether symmetry of division is a key factor in the determination of subsequent development, cells were supplied with the antimicrotubule drug colchicine to disrupt elements of the microtubular cytoskeleton believed to be involved in nuclear positioning. The treatment resulted in a highly significant increase in the numbers of cells turning to sporophytic development; further, timed applications indicated that the cells were sensitive to the drug over a 12-h period immediately prior to pollen mitosis. The results suggest that alteration of division symmetry is sufficient to switch the developmental pathway from gametophytic to sporophytic. These findings are discussed in the perspective of current models proposed for the regulation of development in eukaryotic cells.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Sexual plant reproduction 4 (1991), S. 176-181 
    ISSN: 1432-2145
    Schlagwort(e): Pollen ; Brassica napus ; Mitoses ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Brassica napus pollen development during the formation of the generative cell and sperm cells is analysed with light and electron microscopy. The generative cell is formed as a small lenticular cell attached to the intine, as a result of the unequal first mitosis. After detaching itself from the intine, the generative cell becomes spherical, and its wall morphology changes. Simultaneously, the vegetative nucleus enlarges, becomes euchromatic and forms a large nucleolus. In addition, the cytoplasm of the vegetative cell develops a complex ultrastructure that is characterized by an extensive RER organized in stacks, numerous dictyosomes and Golgi vesicles and a large quantity of lipid bodies. Microbodies, which are present at the mature stage, are not yet formed. The generative cell undergoes an equal division which results in two spindle-shaped sperm cells. This cell division occurs through the concerted action of cell constriction and cell plate formation. The two sperm cells remain enveloped within one continuous vegetative plasma membrane. One sperm cell becomes anchored onto the vegetative nucleus by a long extension enclosed within a deep invagination of the vegetative nucleus. Plastid inheritance appears to be strictly maternal since the sperm cells do not contain plastids; plastids are excluded from the generative cell even in the first mitosis.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    ISSN: 1432-2145
    Schlagwort(e): Self-incompatibility ; S-locus genes ; Brassica napus ; Transgenic plants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Self-compatible Brassica napus var ‘Westar’ was transformed with SLG, the S-locus-derived gene that encodes S-locus-specific glycoproteins (SLSG). Four allelic variants of SLG isolated from self-incompatible B. oleracea and B. campestris strains homozygous for different S alleles were used. We show that the transgenic plants synthesized SLSG with the same apparent charge, molecular weight, and antigenic properties as that produced by the corresponding self-incompatible strains from which the cloned SLG genes were isolated. In addition, transgene-encoded SLSG was detected specifically in the papillar cells of the stigma, and was correctly targeted to the papillar cell wall. However, SLSG was produced at reduced levels in transgenic plants relative to self-incompatible strains. The introduction of the SLG genes did not confer a self-incompatibility phenotype on the ‘Westar’ cultivar.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Sexual plant reproduction 6 (1993), S. 52-56 
    ISSN: 1432-2145
    Schlagwort(e): In vitro culture ; Brassica napus ; Pollination ; Pod ; Seed
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A technique for cultivating isolated flowers of Brassica napus has been developed. Flowers were harvested at anthesis, the surface of their peduncles was then sterilized and they were cultivated in a hormonefree medium. We used an MS medium supplemented with 3% sucrose as a source of organic carbon. From our experiments, it was concluded that no exogenous growth regulator is required to ensure normal growth and development in vitro. The flowers, and thereafter the pods, can be kept in culture until seed maturity. After 30 days, seed development resulted in three types of seeds: (1) normal, (2) milky and (3) aborted. The results show that the number of seeds per pod was not dependent on the order of flowers on the raceme (except the first 10 flowers and flowers above row 50). Our study supports the validity of this model as an easy tool for studying pollination and early seed development.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    ISSN: 1432-2145
    Schlagwort(e): Brassica napus ; Cytoplasmic male sterility ; Polypeptides ; Temperature ; Restoration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Polypeptides were extracted from stamens of a rapeseed (Brassica napus) cultivar, Regent, a near isogenic male-sterile line, Polima-R7 (Pol-R7), and a high-temperature-restored malefertile Pol-R7 (TR) and subsequently separated by two-dimensional isoelectric focusing-polyacrylamide gel electrophoresis under denaturing conditions. Four variable polypeptides with a pI around 6 were observed. Two stamen polypeptides (40000 Da, 38000 Da) were unique to Regent, and the other two (32000 Da, 30000 Da) were unique to the male-sterile Pol-R7. When the male-sterile Pol-R7 was treated with day/night temperatures of 30°/24° C for 7–10 days prior to flowering, both polypeptides unique to Regent reappeared, while the smaller polypeptides disappeared. Temperature-restored male-fertile Pol-R7 (TR) produced fertile pollen, while its short stamen filaments resembled those of the male-sterile Pol-R7. These changes in protein expression may be causally related to the CMS phenotype.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Sexual plant reproduction 3 (1990), S. 263-276 
    ISSN: 1432-2145
    Schlagwort(e): Brassica napus ; Cytoplasmic male sterility ; Microsporogenesis ; Temperature ; Transmission electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary In the ogu cytoplasmic male-sterile (CMS) line of Brassica napus, stamen morphology was influenced by temperature conditions. Under a high temperature regime (27° C/23° C; day/ night) CMS stamens had a near-normal morphology, but microsporogenesis proceeded to a maximum of the microspore stage. However, compared to the normal stamens, the occurrence of sporopollenin-like deposits in the tapetum and deposition of exine on the microspores was sparse. Also, the tapetal cells of the CMS line were often highly vacuolate and failed to degenerate at the same stage as the normal. Ultrastructural changes in the mitochondrial matrix and cristae plus dilation of the endoplasmic reticulum, which occurred during development in sporogenous tissues of the normal line, were often lacking or mistimed in the mutant. Due to extensive variation, even between adjacent locules, the cytological differences between the normal and CMS anthers cannot be ascribed as the cause of male sterility in the ogu CMS line of B. napus, rather they may be the consequence of it.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Sexual plant reproduction 4 (1991), S. 226-234 
    ISSN: 1432-2145
    Schlagwort(e): Male germ unit ; Sperm cells ; Isolation ; Pollen tubes ; Brassica napus ; Pollen-tube inner plasma membrane ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Sperm cells of pollen tubes grown both in vivo and in vitro form a male germ unit. Extensions from both sperm cells of each pollen tube are closely associated with the tube nucleus. A high yield (2.7 × 104. 20 mg−1 pollen grains germinated) of intact sperm cells was obtained following release by osmotic shock from pollen tubes grown in vitro. Structural integrity of isolated sperm was maintained by isolation at low temperature in an osmotically balanced medium. At 4° C many isolated sperm pairs were still enclosed within the pollentube inner plasma membrane. Sperm cells not enclosed within this membrane no longer remained connected as a pair. During isolation vesicles formed on the sperm cell surface from disruption of the fibrillar components bridging the periplasmic space. Both in the pollen tube and after isolation the sperm nucleus is in close association with at least one region of the sperm plasma membrane. Sperm isolated at room temperature showed the presence of nucleopores, and nuclei were euchromatic, instead of heterochromatic as in intact sperm in the pollen tube.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...