Arbuscular Mycorrhizal Fungi Diversity and Contribution to Crop Growth in Agricultural Fields

Arbuscular mycorrhizal (AM) fungi are important soil microorganisms in agroecosystems by enhancing host plant survival and growth.In our survey of AM fungi in the rhizosphere of various crop plants in north and north-west China, thirty three AM fungal species representing seven genera were detected and species richness averaged 2.2 per sample.Glomus etunicatum, G. mosseae and G. intraradices were the dominant species.We also obtained 61 pure isolates, of which 11 pure cultures were registered in the European Bank of the Glomales (BEG).Temporal and spatial dynamics of AMF were studied in the high yield maize system and the result showed that arbuscular colonization, hyphal density, spore density were all reached the maximal at the milk stage of maize (R1 stage).AM fungal community was in a trend of decreasing with increasing soil depth.AMF species richness was decreased signifi cantly only at the depth of 60-90 cm in maize root zone.To estimate the effect of AM fungi on crop growth in agricultural fields, sweet potato, maize, rice, spring onion, taro, strawberry, pimiento, melon, cucumber, tomato and celery were selected as host plants.After pre-inoculation or supply AM inoculum directly in the fi eld, the yield and quality of the crops could be improved.The fertilizer was averaged saving 21%.Moleculer and isotope method were also tentatively used in our present study to monitor of introduced AM fungi, to discriminate the contribution of introduced AM fungi to the crop growth.