Functional activity of VA-mycorrhiza (Glomus mosseae) in the growth and productivity of soybean plants grown in sterilized soil

A greenhouse experiment was conducted to study the response of soybean (Glycine max) to inoculation with the vesicular-arbuscular mycorrhizal fungus Glomus mosseae at flowering and maturity stages of plant growth. Fungal succinate dehydrogenase and alkaline phosphatase activities as enzyme markers were also studied to detect the physiological activity of the VA-mycorrhiza. At the two stages of soybean plant growth, fresh and dry biomass, P and N contents and number of nodules were significantly higher in mycorrhizal plants than that of uninoculated control. However, at the flowering stage, the response of soybean to mycorrhizal infection was higher than that of the maturity stage. VA-mycorrhiza inoculation significantly increased the number and dry matter yield of pods compared to non-mycorrhizal plants. The level of total mycorrhizal infection was not generally related to plant growth and phosphorus content. Fungal alkaline phosphatase staining and, to a lesser extent, succinate dehydrogenase activity showed a relationship between the activity of these enzyme and mycorrhizal growth responses.