关键词: 紫花苜蓿, 根腐病, 从枝菌根真菌, 烟色织孢霉

Abstract: Alfalfa Medicago sativa known as the ‘king of forage’ is a high quality perennial legume. Root rot is a major limiting factor in the production of alfalfa, which can inhibit plant growth, even lead to plant death, and cause huge economic losses. Arbuscular mycorrhizal (AM) fungi widely exists in the agricultural system. It can form endophytic mycorrhizal with plant roots, thereby improving the host plant to absorb nutrients and water, and increasing plant yield and stress resistance. In this paper, alfalfa was used as the experimental material to investigate the effect of AM fungi Glomus mosseae on alfalfa root rot caused by Microdochium tabacinum. The results showed that G. mosseae can inhibit the infection of M. tabacinum, reduce the disease incidence of plants, and the control efficacy reached 20.78%. The infection of pathogens significantly inhibited the plant growth and nutrient uptake. The plant root biomass, root length and root P content were decreased by 12.87%, 20.52% and 18.29%, respectively, while the content of MDA was increased by 12.78%. AM fungi could alleviate the damage and promote alfalfa growth. Compared with the treatment of un-inoculation AM fungi, the shoot biomass, root biomass and root length were increased by 47.77%, 38.67% and 20.67%, respectively; SOD, POD and CAT activities were increased by 42.25%, 26.05% and 33.62%, respectively; shoot P content and root P content were increase by 58.63% and 75.38%, respectively.

Key words: Medicago sativa, root rot, Glomus mosseae, Microdochium tabacinum