Effects of Fragments and Probable Origin of B-chromosomes in Solanum viarum Dunal
1979 年 44 巻 3 号 p. 561-569
詳細
1979 年 44 巻 3 号 p. 561-569
The somatic chromosome number in Solanum viarum Dunal syn. S. khasi anum var. chatterjeeanum Sengupta is 24, however, about 20.64% of plants are either with one or two B-chromosomes. The seeds of normal plant (2n=24) were treated with gamma rays and plants from R2 generation were selected for the study of effect of fragments on the flowering and pollen fertility and the probable origin of B-chromosomes.
The change in the behaviour from self-incompatibility to self-compatibility along with variability in the flowering period, due to fragment bearing S-genes, induces higher adaptability in this plant to cope with changing ecological conditions. Increasing breakability and heterochromatization pave the way for S-gene-bearing fragments to reach the status of neutral and dispensable B-chromosomes.
