Wyniki wyszukiwania - Biblioteka Nauki

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

1 Acta Biologica Cracoviensia. Series Botanica

1 1996

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Polyploidization in the amoeboid anther tapetum of Calla palustris L. [Araceae]

100%

Deregowska R. , Turala-Szybowska K.

Acta Biologica Cracoviensia. Series Botanica

1996

tom 38

In Calla palustris L. (Araceae) the anther tapetum (AT) of the amoeboid type occurs. Till the stage of I telophase in pollen mother cells (PMCs), the AT of this species has a cellular character. In premeiotic stage and during 1 meiotic division in PMCs, the differentiation of the AT is accompanied by two mitotic divisions which do not occur in all tapetal cells (TCs). The first mitosis may be acytokinetic resulting in the formation of a number of binucleate TCs. The nuclei of ca 40% TCs remain on the diploid level. Polyploidization of the nuclei in uni- and binucleate TCs is mainly connected with inhibition of mitoses at prophase. As a result, in the majority of the TCs the polyploid nuclei of regular shape arise. The polyploidization may be due also to nuclear restitution or fusion of chromosome groups at metaphase and anaphase which leads to the formation of nuclei of irregular outlines. The dissolution of the cell walls in the TCs begins already at the end of I prophase in PMCs. The fusion of the protoplasts is accomplished at the tetrad stage and the periplasmodium intruding the anther loculus is formed. At the tetrad stage in the AT of C. palustris three volume classes of the nuclei corresponding to the diploid, tetraploid and octoploid levels were distinguished.