Induced Quantitative Variation in Self-Compatible and Self-Incompatible Forms in Brassica

The polygenic variation for plant height and number of branches per plant was studied in self-compatible and self-incompatible races of cultivar Brown Sarson from M1 to M4 after exposing the dry seeds to varying dosages of gamma rays and thermal neutrons. While the mean and the coefficient of variation in the irradiated M1 material decreased, in M2 and later generations it increased in comparison to the M1 generation. The release of additional variability was highest in the advanced M1 generation in both races. The data provided evidence of greater response of self-compatible race to ionizing radiations compared to the self-incompatible race.