The Field Inoculation Effect Of Am Fungi On Soybean Growth

Arbuscular mycorrhizal (AM) fungi are kinds of endotrophic mycorrhiza and can form a symbiotic association with most terrestrial plants. This kind of symbiosis can promote plant growth, improve crop yields, enhance plant absorption of soil nutrients, and in addition can strengthen plant resistance, improved soil structure, so the development and application of mycorrhizal bio-fertilizers has gradually gotten increasing attention. On the other hand, as Heilongjiang Province being China’s main grain producing areas and soybean is the most important economic crops, research on the impact that AM on soybean growth be carried out in the field is of great importance.Soybean selected as host plants inoculated with Glomus mosseae (GM) and Glomus intraradices(GI), fertilization group and mock-inoculated plants (non fertilization and non-inoculation, CK) took as control, this research investigated the impact AM fungi inoculation had on soybean biomass, soybean rhizosphere soil microorganism, soybean rhizosphere soil enzyme activity and soybean soil minerals. In addition, PCR-DGGE technology was employed to study the dynamic distribution of artificial inoculated AM fungi in the field and their competitive relationship with native AM fungi.The results showed that both the two AM fungi strains could colonize soybean roots and form mycorrhizea, the colonization percentage with GM inoculation arrived at86.6%and78.3%with GI inoculation. However, AM fungi colonization had also been detected on CK and fertilization treatments on all their growth periods, the highest colonization percentage of which were16%and15.3%respectively, implying the existence of native AM fungi which could colonized soybean. Inoculating the two AM fungi strains could significantly increase the biomass of soybean plants, and compared to CK, GM inoculation and GI inoculation raised the soybean yields by up to7.38%and3.88%respectively, of which that with GM inoculation was higher than fertilization treatments, while that with GI inoculation was lower than fertilization treatments.Inoculation with AM fungi could raise the amount of soybean root nodule and of soil rhizosphere microorganisms, and enhanced plant absorption of soil minerals. Besides, inoculating AM fungi had a great influence on soil urease activity and peroxidase activity of soybean rhizosphere compared to CK, both of which increased firstly and reached the maximum at branching stage, and decreased afterward.Fourteen DGGE bands were selected for sequencing. The results showed that the14DGGE bands were all belonging to Glomus, among which five sequences from soybean system and rhizosphere had a high identify to G. mosseae and G. intraradices used in this experiment. About the other9sequences,8sequences belong to Uncultured Glomus, and one band showed a high similarity to Glomus viscosum.