中文摘要：

植物根部真菌群落结构和多样性与植物的抗病性和病害的危害程度相互影响。为揭示松萎蔫病与松树根部真菌群落的相互作用,该研究对陕西省商洛市柞水县松萎蔫病发生区和未发生区油松的根尖活性、根部外生菌根真菌（ECMF）和深色有隔内生真菌（DSE）的侵染率进行分析,并通过油松根部可培养真菌的分离和鉴定,分析了两地油松根部真菌的群落结构及多样性。结果显示：（1）松萎蔫病未发生区油松根部的活性根尖比、菌根根尖比和ECMF的侵染率均显著高于发生区,而DSE的侵染率和微菌核密度却低于松萎蔫病发生区,ECMF的侵染率在两个样区油松根部都显著高于DSE。（2）从两个样区油松根部共分离到131个菌株,根据形态和分子学特征最终鉴定为23种真菌,其中DSE占绝对优势,且Phialocephala fortinii和Cryptosporiopsis ericae为油松根部分离真菌的优势种。（3）两个样区真菌的群落组成存在明显差异,共有真菌仅5种。（4）松萎蔫病未发生区真菌群落的丰富度（17）和多样性（2.012 0）、以及ECMF的相对丰度（8%）都高于松萎蔫病发生区（分别为11、1.197 9和1.6%）,而DSE的相对丰度（70%）却明显低于发生区（82.7%）。研究表明,松萎蔫病的发生影响了油松根部的活性、菌根的形成、ECMF和DSE的侵染,以及根部真菌的群落组成和多样性。该文首次报道了DSE与松萎蔫病的关系,但分离真菌对油松松萎蔫病抗性的影响有待进一步研究。

英文摘要：

There is an interaction between the root fungal community and the plant disease.In order to uncover the interaction between the pine wilt disease and fungal community in the root of pine tree,we investigated the activity of root tips,the colonization rates of ectomycorrhizal fungi（ECMF）and dark septate endophytes（DSE）,and analyzed the root fungal community structures and diversities of Pinus tabuliformis in the pine wilt disease damaged and undamaged areas through the isolation and identification of culturable fungi.The results showed that：（1）Not only the ratio of active root tips and ectomycorrhizal tips,but also the colonization rate of ECMF were significantly higher in pine wilt disease undamaged area than those in damaged area（P〈0.05）,while the colonization rate of DSE and the density of microsclerotium were lowerthan damaged area.The colonization rates of ECMF were significantly higher（P〈0.05）than those of DSE in both of the two sample areas.（2）Based on the morphological and molecular characteristics of 131 isolates,they were finally identified as 23 species,in which,the dominant fungi were DSE,especially Phialocephala fortinii and Cryptosporiopsis ericae.（3）The two sample areas only shared 5species,exhibited obvious difference in root fungal community structure and diversity.（4）In the pine wilt disease undamaged area,the richness（17）and Shannon-Wiener biodiversity index（2.012 0）of root fungal community,as well as the relative abundance of ECMF（8%）were higher than those in damaged area（11,1.197 9and 1.6%,respectively）,but the relative abundance of DSE（70%）was lower than that in damaged area（82.7%）.Above all,it is suggested that the outbreak of pine wilt disease affected the root activity,ectomycorrhizal development,colonization of ECMF and DSE,as well as the fungal community structure and diversity.This is the first report about the relationship between DSE and pine wilt disease.Further research is required to make clear the influence of these iso