The effect of B chromosome on chiasma frequency and distribution in number of pollen mother cells (PMCs) was studied in Plantago lanceolata. The effect of chemical mutagens on chiasma frequency in carrier and non-carrier PMCs was also studied and compared with that of control. The treatment of Hydrazine-hydrate (HZ) along with Dimethyl-Sulfoxide (DMSO) as a penetrant carrier was given in two different ways. Firstly, both the chemicals were mixed and treated and secondly, sequential treatment of DMSO and HZ was given. Chiasma frequency in carrier and non-carrier plants was calculated in response to mutagenic treatment and compared with that of controls. B chromosomes were found to influence chaisma frequency during mutagenic treatments, however, the frequency of B chromosomes remained unchanged.
