Studies on the Radiation Breeding in the genus Mentha : (XII) Variation in Quantitative Characters of X2 plant after Hybridization and Irradiation in Mint

The present paper describes some aspects of inducing genetic variation of polygenically controlled characters following the irradiation of two mint species and their hybrids. The data for the characters studied in X2 generations were analyzed by appropriate analysis of variance. In all the cases, the mean value of the irradiated population with respect to seed size character was almost the same as that of the non-irradiated control, while the variance of the irradiated population increased. On the other hand, for endosperm quality the irradiated populations showed increase in the mean value and the variance. The results obtained in the present experiment suggest that back-ground geno-types played an important role in the manifestation of mutated characters.