Badania cytoembriologiczne nad Prunus Domestica odmiana Węgierka z Bühlerthal

Abstract

The object of the present inwestigation has been to study and follow the course of sporogenesis and gametogenesis in Prunus Domestica, the Bühlerthal variety of wild-plum. As a result the author has been able to state that the process of microsporogeneBsis does not deviate from norm. In the prophase of the first meiotic division the homological chromosomes were coniugated under the from of 24 bivalents; in the subsequent phases they separated in a regular way and made the usual journey to the opposite poles. Just like in the case of microsporogenesis, chromosome coniugation in the mother cells of macrospores follows a regular course, determining the proper division of chromosomes going to the breeding cells. The macrospore tetrad is disposed in a linear way, each macrospore comprising the chromosome number n = 24. The ovular pouch is of Polygonum type, one-spore. and eight-nuclear. The ingrowth of pollen-tubes to the pouch was made in groups of a few each, usually from the micropylar side. The double-fertilization process follows a regular course; as a result of this process a zygote is formed, from which after successive mitotic divisions the bud seed is produced. A nuclear-type endosperm originates from the inseminated secondary nucleus. The research was conducted at the Department of General Botany of the Adam Mickiewicz University of Poznań. I wish to acknowledge my gratitude to Professor Dr Stefan Krupko on whose instigation I have undertaken work on this interesting subject and who has kindly aided me while I was working on it. I am also deeply indebted to Docent Mieczysław Rozmus Head of the Botany Department at the Teachers' Training College in Cracow for the most valuable advice he was kind to offer me when I was preparing the paper for print.