2010 年 75 巻 1 号 p. 59-63
The present study documents the presence of 3 B chromosomes in safflower, which is one of the first such reports. During the present investigation, B chromosomes were found to induce a twofold effect on planting, firstly a reduction in chiasma frequency in euchromatic region, and secondly depression in the percentage of pollen fertility due to an increase in the number of unpaired chromosomes. Although the presence of Bs depressed the chiasma frequency of the regular complement, the frequency of A and B chromosomes does not appear to be related. No correlation between B chromosomes and phenotype has been reported. Thus, it can be predicted that the presence of additional DNA as B chromosomes can bring about some structural or numerical changes in the long run and may affect the genetic integrity of the plant and thus result in a changed genotype with negligible effect on the morphology and vigor of the plant.