Badania nad Polygonum Viviparum L. z Tatr

Abstract

The present work was carried out on Polygonum viviparum L. from the Tatra Mts. The somatic chromosome number established for Polish representatives of this apomictic species in ca 130 (132); thus Polygonum viviparum in Poland represents a very high degree of polyploidy. The aim of this study was to investigate the problems of the structure and of the abortion of flowers as well as the origin of vegetative bulbils developed by this viviparous plant. In the flowers, different types of abnormalities could be observed. The high percentage (40-80) of pollen graws prooved to be abortive. The still higher degree of degeneration occurs in ovules. The number of flowers with more or less normal embryo-sacs does not attain 10%. In the majority of flowers both nucellar tissue and the integuments become resorbed, and all flowers are dropped. Neither the embryos nor seeds formation was observed. The propagation takes place thorough vegetative bulbils localised in the inflorescences. The study of the origin of the bulbils was based at the analysis of microtom sections of young spikes (5-14 mm long), in successive stages of development. The bulbils notably proceed the flower buds in their development; already in the earliest stages available, they were well differentiated while the flower buds were still discernable in the form of young primordia. The comparison of early stages of development of flowers and bulbils, their position on the inflorescences, as well as the close similarity of the histological structure permitt to assume that they represent organs of common origin. The complete break-down of sexual reproduction and the propagation only thorough the vegetative bulbils is presumably connected with the high level of polyploidy of this apomictic species.