GROUNDNUT IMPROVEMENT: GENETIC VARIABILITY INDUCTION FOR GROWTH ASPECTS AND POD YIELD IN GROUNDNUT (Arachis hypogaea L.) THROUGH GAMMA IRRADIATION

The present study aims to estimate the genetic variability of some different quantitative traits for some mutant lines resulted from two different genotypes i.e., Giza-6 and NC-1. During 2014 season, groundnut seeds of the both genotypes (Giza-6 and NC-1) were treated with physical mutagenic agents of gamma irradiation doses (0, 100, 200 and 300 Gy). Respect to M1 generation, significant effect of gamma irradiation doses was detected on germination ratio, crop growth rates (CGR), pods yield and the growth traits (roots, shoots, leaves, pods and total biological yield as dry weights). The results showed significant reductions in germination ratio which reached to 38.56, 33.5 and 23.39% under 100, 200 and 300 Gy, respectively as compared to a control treatment (85.0%). Respect to growth analysis, among the various dose of gamma rays treatment, the low level (100 Gy) caused an increasing in crop growth rates by (25.49 and 41.8% for 1st and 2nd intervals, respectively) as compared to a control treatment. Concerning M2 generation, gamma irradiation dose at 100 Gy increased significantly the pods yield/plant in gm. by 44.2% for Giza- 6 and 50.6% for NC-1as compared to control treatment. Meanwhile, for the total biological yield plant-1, there was a significant increase of 59.6% for Giza 6, and 122.7% for NC-1 at 100 Gy as compared to control treatment. On the other hand, higher dose of gamma rays (300 Gy) caused significant reduction in plant growth and pods yield and the other contribution traits.