الفهرس 
Genetic materialOnly 14 pages are availabe for public view
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Abstract
Seeds from two varieties of common bean (Phaseolus vulgaris) were irradiated with four doses of gamma rays to create mutants affecting Rhizobium symbiosis, because the development of N2fixing nodules requires a coordinated expression of genes of both symbiotic partners. Symbiotic response to radiation affecting on leguminous host was measured through two generations using wild type strain of rhizobia. Genetic modification induced by gamma rays affect to form nodules in F2 plants rather than they are not developed in the roots of F1 plants. Both doses of 20 and 40 Krad revealed higher symbiotic efficiency in F1 and F2 populations, respectively. In addition, nodules developmented per plant in F2 generation were significantly affected by doses of gamma rays and biofertilization. Plants inoculated with rhizobia shown more tolerant to gamma irradiation than uninoculated ones. Gamma irradiation affecting to disrupted the normal morpholgenesis leading to reduce the development of new tissues in vegetative traits. Leaf area was markedly reduced by gamma irradiation, it was suitable for radiosensitivity depending on the growth of genotypes. Leaf area was significantly affected by both doses of gamma irradiation and biofertilization among F1 and F2 populations. Protein content and chlorophyll concentrations in most of the inoculated plants became higher than uninoculated ones. Plants inoculated with rhizobia produced high seed protein content than uninoculated ones. The interaction between varieties by biofertilization significantly affect on shoot nitrogen content among F1 and F2 populations. Total chlorophyll concentrations were markedly affected by plant genotypes, doses of gamma irradiation, biofertilization, and the interaction between doses of gamma irradiation by biofertilization among F1 and F2 populations. Pod productivity in both generations shown markedly affected by plant genotypes, doses of gamma rays and biofertilization. Reductions in seed and pod yields / plant were observed in F1 and F2 populations as dosages of gamma rays progressed. The results indicated that plant is most sensitive to gamma irradiation from the time it begins to develop its reproductive capability until after fertilization when embryo development begins. Irradiation was used in this work to induce heterogeneity in common bean for better management in response of rhizobia with the legume host to increased N2 fixation through genetic diversity in common bean