The Factors Effecting on Community Structure of Arbuscular Mycorrhizal Fungi Infected in the Soybean (Glycine max L.) Roots and Rhizosphere.

It is well known that the host crops and the soil physicochemical characteristic affected the community structures of AM fungi. In the previous paper, we reported that the community structure of AM fungi colonized in field crops (soybean and maize plants) greatly differed between regions. However, the reason of which the community structure of AM fungi differs between regions is not clarified. In this paper, we investigated that the reasons of which the community structure of AM fungi differed between regions to detected AM fungal species which colonized in soybean roots and the spores in the rhizosphere soil. The soybean roots and rhizosphere soil samples were collected in Kanagawa (temperate climate region) and Hokkaido (cool climate region). The number of sampling sites in Kanagawa and Hokkaido were 6 and 4, respectively. DNA was extracted from roots and spores, and the base sequence of partial LSU rDNA region for AM fungi were amplified and analyzed. Gigasporaceae group (Gigaspora and Scutellospora genus) were not detected from the all root and spore samples collected in Hokkaido. On the other hand, Scutellospora genus were detected from the all roots collected in Kanagawa were more various than that collected in Hokkaido. The detected AM fungal groups were different in Hokkaido and Kanagawa. For example, in the root samples of Hokkaido, Glomus intraradices were detected, and in the sample of Kanagawa, Glomus mosseae was detected mainly. From above fact, it was clarified that the community structure of AM fungi were differed between Hokkaido and Kanagawa. And it was clarified that the causes of the difference of the community structure of AM fungi in regions were not soil chemistry, soil type and preceding crops.