Influence of B-chromosomes on meiosis in pearl millet |
| |
Authors: | J V Pantulu V Manga |
| |
Institution: | 1. Department of Botany, Andhra University, Waltair, A.P., India
|
| |
Abstract: | B-chromosome behaviour and the effects of B's on the endophenotype were studied in the third back-cross progeny of a cross between non-B and B-carrying parents ofPennisetum typhoides Stapf et Hubb. In the experimental material a regular increase in B-chromosome chiasma frequency and an increase in the variation of mean chiasma frequency with increased number of B's was observed. When four or more B-chromosomes were present quadrivalents occurred more frequently. In these respects the experimental material differed from the B-carrying parent. B's had no effect on the mean chiasma frequency of A-chromosomes when present in numbers of up to and including four but when present in numbers of more than four had a depressing effect. The variation of the mean chiasma frequency of the A-chromosomes increased with increasing number of B's. No correlation was observed between A-chromosome chiasma frequencies and B-chromosome chiasma frequencies. In the experimental material B's when present in larger numbers i.e. more than four had deleterious effects on A-chromosome behaviour and on fertility. In the effects of B's on the endophenotypic characters the experimental material differed from the B-carrying parent. It is suggested that the behaviour and effects of B's on the endophenotypic characters are the result of interaction between the A-chromosome genotype and the B-chromosomes. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|