Abstract:In order to understand the effect of arbuscular mycorrhizal fungi (AMF) on growth and photosynthetic physiology of Betula alnoides, four clone seedlings were inoculated with six arbuscular mycorrhizal fungi (AMF) and grown in greenhouse, and then seedling growth, photosynthetic parameters, chlorophyll contents and fluorescence parameters were investigated. The result showed that all six AMFs could form symbiote with seedlings of B. alnoides clones. After inoculated with Glomus intraradices (AMF5) and G. mosseae HUN03B strain (AMF3), the seedling growth, net photosynthetic rate, water use efficiency, chlorophyll contents and fluorescence parameters were significantly enhanced (P<0.05), indicating that affinity of AMF5 and AMF3 with clones was obviously better than that of other AMFs. There were no significant differences in inoculation rate among four clones, but the promotion effect of AMF inoculation on growth and photosynthetic physiology of FB4 and BY1 were obviously better than those of FB4+ and A5. Therefore, the optimal AMF strains were AMF5 and AMF3 for B. alnoides, which would provide theoretical foundation to its mycorrhizal seedling cultivation.