Survey And Analysis Of Mycorrhizal Diversity In Zijin Mountain

Ectomycorrhizal fungi (EMF), a large class of mycorrhizal fungi, are ubiquitous in forest ecosystem. More than 6000 species of ECM have been found in forest ecosystem so far. These fungi can form mutually beneficial symbiotic relationship with host plants. The symbiosis improve host performance by enhancing nutrient and water uptake from the soil and protecting host roots from pathogens and toxic compounds.Zijin Mountain, locating in Yangtze River downstream area, has a large number of various large fungi and a wide range of plants. It is a valuable site for scientific researches on plant and fungal communities in north subtropical China. Previous studies had done a lot of sporocarp morphological identifications on mycorrhizas in Zijin Mountain. But no study has focused on the ectomycorrhizal fungal community structure underground of this mountain. Molecular analysis identification can provide detailed information of underground ectomycorrhizal fungal community.To investigate the EMF communitiy structure in Zijin Mountain, eleven sampling sites having pine and oak trees and locating in different altitudes were conducted in Zijin Mountain. The numberof sampling soil cores within each site were 25. Three individuals of pine and three oak were saparately selected in each sampling site. For each individual of tree, three root systems were sampled. Results indicated that 40,14 and 59 of EMF RFLP types were identified from pine trees, oak trees and soil cores, respectively.40 of EMF RFLP types identified in soil core samples were shared with those in root system samples of pine and oak trees. Only two shared EMF RFLP types were found between pine and oak trees. Diversity indices indicate that the EMF diversity of pine trees is significantly higher than tthat of oak trees. These results suggest that there are different EMF communities between pine and oak trees in Zijin Mountain.The results also indicated that the altitudes influenced on EMF community structure and diversity in Zijin Mountain to some extent. At low, middle and high attitudes, different dominant EMFs and special EMFs were found, respectively. In oak trees, the EMF diversity at the middle altitude was higher than those at low and high altitudes but this trend was not found in pine trees. In pine trees, the EMF diversities at different altitudes were not significantly different. In soil core samples, the EMF diversities at high and middle altitudes were higher than those at the low altitude. The EMF diversity in 418m altitude was the highest. The analysis of nutrient content and pH of soil samples collected from different altitudes in Zijin Mountain indicated that the soil in Zijin Mountain was weakly acid and the nutrient contents at the 418 m altitude was significantly higher than those at low and middle altitudes. These results suggest that the nutrient condition may be a dominant factor influencing the EMF community and diversity in Zijin Mountain.The present research is the first time to investigate the diversity of ectomycorrhizal fungi in Zijin Mountain by ITS polymorphism analysis method.