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Wyszukujesz frazę "cytoembryology" wg kryterium: Temat


Wyświetlanie 1-2 z 2
Tytuł:
Cytoembryological analysis of causes for poor seed set in alfalfa (Medicago sativa L.)
Autorzy:
Mol, R.
Weigt, D.
Broda, Z.
Powiązania:
https://bibliotekanauki.pl/articles/19337.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cytoembryology
seed
alfalfa
Medicago sativa
seed set
pollen tube
embryonic development
inflorescence mutant
pollen germination
plant breeding
Opis:
Poor seed set is a limiting factor in alfalfa breeding, as it slows the selection response. One strategy used to overcome this problem is to search for mutations of inflorescence morphology. Long-peduncle (lp), branched-raceme (br) and top-flowering (tf) inflorescence mutations increase the number of flowers per inflorescence, but they do not improve seed set per flower. Here we assessed pollen tube growth in styles of those inflorescence mutants and we observed embryo and endosperm development in seeds 1 to 16 days after pollination (DAP). The number of pollen tubes penetrating the style and the ovary was similar in all tested mutants and in the reference cultivar Radius. At 2 DAP, fertilized ovules were 2.7–3.9 times less numerous in certain inflorescence mutants than in the short-raceme cv. Radius. Ovule degeneration progressed at 2–4 DAP in all analyzed plants. Most ovules were not properly developed in the control cultivar (62%), nor in the forms with mutated inflorescence morphology (69–86%). The number of seeds per pod was lowest in the tf form despite its having the highest number of ovules per ovary. It appears that the number of ovules per pistil is not a crucial factor in seed set in alfalfa when fertilization efficiency is very low. Both poor fertilization and gradual ovule degeneration were factors causing poor seed set in the investigated alfalfa genotypes.
Źródło:
Acta Biologica Cracoviensia. Series Botanica; 2011, 53, 1
0001-5296
Pojawia się w:
Acta Biologica Cracoviensia. Series Botanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cytoembryology of infertile segregants of the hybrid Lupinus varius L. x L. digitatus Forsk
Autorzy:
Kazimierska, E M
Kazimierski, T.
Powiązania:
https://bibliotekanauki.pl/articles/2048189.pdf
Data publikacji:
1995
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Lupinus digitatus
cytoembryology
embryology
interspecific hybrid
plant genetics
gametophyte
sterility
vacuolation
sporophyte
megasporogenesis
megagametogenesis
chromosome
Lupinus varius
hybrid
sporogenic cell
Opis:
In F₂, F₃ and F₄ generations of one hybrid line of Lupinus varius × L. digitatus, segregation into infertile and fertile plants in the ratio 3:1 was observed. Cytoembryological analyses showed that sterility was caused by irregularities in megasporocyte formation, in megasporogenesis and megagametogenesis. The following abnormalities lead to female sterility: no megasporogenic cells separated in nucelluses; in other nucelluses with megaspore mother cells, these cells underwent vacuolation and died before reduction division. In the megaspore mother cells, in which probably meiosis occurs, the megasporocyte division is irregular; a restitution nucleus is frequently formed after reduction division and such megasporocyte develops into an embryo sac. In 8-nucleate embryo sacs a change in the nucellus polarization was observed, while in rarely encountered embryo sacs the embryo cells underwent vacuolation and then died. Female sterility in the studied segregants is determined genetically, whereas sterilization of reproduction cells is a developing process throughout the period of sporocyte and female gametophyte formation.
Źródło:
Journal of Applied Genetics; 1995, 36, 3; 215-227
1234-1983
Pojawia się w:
Journal of Applied Genetics
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

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