Induced polygenic variability in two New Pusa wheats

Dry seeds of N.P. 823 and N.P. 860 were treated with X-rays (20 kr. and 30 kr.). Data were collected for some quantitative characters in M₂ and M₃ generations and mean, standard deviation and coefficient of variation were worked out on plant to plant basis. Means of different characters in the irradiated treatments were not appreciably influenced except for plant height in M₂ generation. However, the higher dosage of irradiation increased correspondingly the spectrum of variability in all the characters particularly in the case of ear length and plant height. In the study of M₂ population, there was no particular advantage in selecting bulks of M₁ from the main shoot versus side tillers. Similarly for M₃ generation bulks originating from such of the M₂ plants whose yields were higher than the mean of the control did not show any advantage over the bulks from all the plants irrespective of their individual yield levels.