• Microbiology and Biotechnology Letters
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• v.19 no.6
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• pp.548-552
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• 1991

The effect of dual inoculation with vesicular-arbuscular (VA) mycorrhizal fungi, Glomus mosseae, and Bradyrhizobium sp. R938 on the nitrogenase activity of peanut plant (Arachis hypogeae L. cv. Youngho) was studied in pot experiment. As a result of the dual inoculation with Glomus mosseae and Bradyrhizobium on peanut plant, nitrogenase activity was increased by 1.5 times compared with single inoculation with Bradyrhizobium sp. R938. After 69 days growth of peanut plant, the size of nodules was also increased due to the mycorrhizal infection. The mean fresh weight per nodule was 6.7 mg in treatment with the dual inoculation, which is the 1.5 times increase compared with single inoculation with Bradyrhizobium sp. R938. These results suggested that there might be a hormonal effect of VA mycorrhizal fungi in addition to the effect of increase in nitrogen fixing ability through the enhancement of nutrient absorption.