Abstract

The nature of induced mutation for polygenic variability was studied in two traditional aromatic rice genotypes, viz., Kalanamak and Badshah Bhog. Induced variability was observed in both the M₂ and M₃ generations indicated the possible selection for quantitative characters. The shift in mean was not found to be unidirectional nor equally in both directions in all the treatments. Most of the mutagenic families in different treatments showed shift in mean toward negative side coupled with high range and CV as compared to their respective control. In general, combination treatments of 30kR gamma-ray+ 0.2% EMS and 40 kR gamma-ray+ 0.2% EMS induced maximum variability for most of the traits. The use of physical and chemical mutagens or a combination of both has been an important tool for the increase of variability in agronomic traits. In general, there was reduction in variability, as judged from range and CV, in M₃ as compared to M₂ in all the treatments and traits in both the genotypes. The present investigation had clearly demonstrated the high potentials of  40 kR gamma-ray +0.2% EMS followed by 40 kR gamma-ray and 30 kR gamma-ray +0.2% EMS were found to be more useful in releasing desirable variability for yield and component traits in desired directions for most of the characters in both the genotypes in both the generations.

Key words: Kalanamak, Badshah Bhog, polygenic variability, micro-mutations.