Radiation induced variability in improvement of brown sarson

Abstract

Kumar P.R. Radiation induced variability in improvement of brown sarson . Radiation Botany 12 , 309–313, 1972.-A study was undertaken to improve the flowering time and the number of seeds per siliqua in highly cross pollinated Brassica campestris L. var. dichotoma Watt. (cv. brown sarson). Dry seeds of three strains of cultivar brown sarson were exposed to varying doses of gamma rays and thermal neutrons and grown during 1965–1969. The pattern of release of polygenic variability and the degree of shifts in mean values were examined in terms of range, coefficient of variation and the mean from the M 2 to M 4 generation. Selection was practised in M 3 plants which were at least 10 days earlier in first flowering and with a minimum of 20 seeds per siliqua. The selected genotypes were permitted to intercross in isolations in the M 4 generation. The specific radiation treatments generated additional variability without altering the mean values of two traits in different generations. In the M 4 generation, a high degree of variability was released which afforded opportunity for stabilizing the mean values of these two polygenic traits of high economic value in the M 5 generation at a desired level.