MUTATION GENETIC STUDIES IN ONION II. INDUCED VARIABILITY IN QUANTITATIVE TRAITS AND MORPHOLOGICAL ANOMALITIES

A very high magnitude of M1 variability in various metric traits was induced in the onion variety “ Pusa Red’ by using physical (gamma rays) and chemical mutagens (EMS, DES and Sodium azide) singly and in combinations. This variability though broad was not random and was positively skewed. Gamma ray treated seeds produced more taller plants, bulbs of large size and torpedo shape. The variations in bulb weight as induced by EMS treatments and in bulb shape as induced by physical + chemical treatments are of genetic significance since the genotypic variance, heritability, obtained and expected genetic advance values are very high for these treatments as compared to others. Many anomalous morphological types, partially and totally sterile phenotypes and viviparous types were also recovered in M1. generation, plants.