Improving Peanut Productivity and Resistance to Aspergillus flavus L Through mutation Induction

The present study was conducted to improve peanut productivity and resistance to Aspergillus flavus that caused aflatoxin formation in peanut seeds . To achieve these goals , dry seeds of the two local varieties (Giza 4 and Giza5) were irradiated with gamma ray doses of 0 , 50 , 100 , 150 , 200 , 250 , 300 Gy. The irradiated seeds were sown to get the M1 and M2 generations. Six high yielding mutants were selected in M2 from irradiated populations of 150 Gy and 200 Gy for Giza 4 and Giza 5 respectively. These mutants were evaluated in M3 generation for yield and yield components , quality traits (protein and oil content) and the resistance to Aspergillus flavus infection. The obtained results revealed that analysis of variance for Giza 4 selected mutants showed significant differences between genotypes for different studied characters except for plant height and no. of branches /plant .However, for Giza5 selected mutants, significant differences between genotypes were only obtained for plant height , no of pods/plant, weight of pods/plant, weight of seeds/plant, and weight of 100 seeds. Different M3 mutants that selected from irradiated populations of both two peanut cultivars Giza4 and Giza5 shod marked improvement for yield and yield components, and quality traits in comparison with their mother varieties.The results of M3 progeny test indicated that most selected mutants retained the features of their M2 selectors, suggesting that they were considered true breeding materials. For Giza 4 selected mutants, aflatoxin concentrations ranged from 31.11 μg for mutant 1 to 188.46 μ g for mutant3 in comparison with 42.76 μg for the mother variety Giza 4. The lowest yielding progenies of mutant1 (1 ) showed the lowest aflatoxin concentrations as compared with the mother variety Giza 4 and other mutants, therefore the use of induced mutations for peanut improvement may be led to the development of improved varieties .However, for Giza 5 selected mutants aflatoxin concentrations in seeds ranged from 18.75 μg for mutant 4 to 41.58 μg for mutant 4 as compared with 18.0 μg for the mother variety Giza 5. Aflatoxin concentrations for different mutants were higher than that of the mother variety Giza 5. Mutant 4 showed high seed productivity and very slight increase of aflatoxin concentrations as compared with Giza 5 and other selected mutants ,indicating that this mutant could be improved through crossing it with the mother variety and other mutants. (author)