Gene Action for yield attributing characters in segregating generation (M2) of Sorghum (Sorghum bicolor L.)

Gamma rays was used as a physical mutagen to create variability and to study the gene action through mutation in Grainsorghum variety CO(S) 28.The LD 50 for germination was observed as 35 kR and the treatment doses viz., 25 kR, 35 kR and45 kR were fixed for creating variability. The M1 generation of all the three treatment doses was raised and selfed plantswere forwarded as M2 generation. Approximately 1500 M2 plants were raised in each treatment for recording observations.The frequency distribution for the yield and yield attributing traits viz., panicle length, number of primary branches perpanicle, number of grains per panicle, 100 grain weight and grain yield per plant were obtained. The Skewness and Kurtosisestimate were calculated to study the gene action. The traits viz., number of grains per panicle and grain yield per plantrecorded positive Skewness value in all the three irradiated doses. This indicates the presence of complementary epistaticgene action for these traits and if selection will be made intensively in the segregating generations the gain will be faster andmild selection resulted in slower gain.