32P usage for assessment of the effective mycorrhizal fungus strain for symbiosis with barley (Hordeum vulgare L.) and alfalfa (Medicago sativa L.)

Nuclear approaches are used to determine neighboring and measurement of translocation and nutrients exchange rate between plant and mycorrhizal fungus and selection of effective mycorrhizal strain. Two pot experiments were carried out for determining the effective mycorrhizal fungi strains in alfalfa and barley at Agricultural, Medicinal and Industrial School, Institute of Nuclear Science and Technology, Karaj, Iran. Strains were consisted of G. mosseae, G. intraradices, G. etanicatum and mixed strain (combination of G. mosseae, Giagaspora hartiga and G. fasciculatum) with radioisotope technique. 32P added in the maximum vegetative growth stage to the pots. 32P activity in plant samples were counted by β counter (Multi low level counter FHT770-Eberline Co.). In barley, G. mosseae had more ability of 32P uptake than other strain. These plants had the highest 32P activity of leaf, stem and spike and had higher efficiency in shoot biomass accumulation. Alfalfa- G. mosseae relation were produced the highest shoot dry weight, 32P activity in leaf and stem and specific activity. In general, the strains were different in symbiosis with alfalfa and barley. But, efficiency of G. mosseae in 32P uptake enhanced growth and dry matter production by alfalfa and barley, so G. mosseae can be introduced as an effective strain for both alfalfa and barley.