Studying the Effect of Mutations on some genotypes of Peanut

: Peanut crop has a great economic value and it has special growth nature caused some difficulties in genetic improvement. This study aims to carry some genetic variations and improvement through treating seeds of four varieties of peanut with concentrations of mutagenic substance like sodium azid. An experiment was conducted at the Experimental Farm, Ismailia Research Station; Oil Crops Section- Agricultural Research Center (A.R.C). Four varieties of peanut (Giza 6, Var.112, Var.57, and Var.381) were treated with three different concentrations of sodium azide (NaN 3 ); 0.00 control (0.00), T1 (0.01) and T2 (0.03) % W/V for inducing mutation and planted in a randomized complete block design (RCBD) with three replications. The general mean of all 4 varieties was higher in the M1 than those in the M2 generation. T1 and T2 mutated plants displayed a high value of the stem height compared to control plants for all 4 varieties, The largest increase in branches per plant was observed in the M2 generation at a low dose of mutagen while the seeds number and 100 seeds weight were less than control at the low dose of mutagen in both generations. The values of phenotypic coefficient of variability (P.C.V. %) and genotypic coefficient of variability (G.C.V. %) were greater in the M1 generation than those in the M2 generation. GCV was less than PCV in SPAD, stem height, number of branches/plant, number of pods/plant and pod yield (Ardab / Fadden ) . While GCV was more or less equal to PCV for pod weight/plant, 100 pod weight, and seed yield (seeds number/plant, seed weight/plant, and 100 seed weight) as well as oil percentage. Heritability values exceeded 65% for all traits examined in both the M1 and M2 generations, T2 mutant plants in the M2 generation had higher heritability scores than those in the M1 generation. They scored values between 82% and 99.88% for most of the traits investigated and all studied traits recorded different values of genetic gain by selection (GS), ranging from 0.7 to 105.8 and from 2.5 to 108.7 in M1 and M2 generations, respectively. 0.01% and 0.03% of sodium azide played an important role in inducing mutation to improve the quantitative characters of selected peanut varieties.