Study Of Ascomycetous Species On Branches Disease From Desert Plants In Xinjiang

The unique geographical environment and climatic characteristics of Xinjiang,making trees susceptible to extreme weather,resulting in weakened tree vigor,lead to the occurrence and prevalence of disease easily.Desert plants are one of the main body of forestry in Xinjiang,it accounts for 52.9% of Xinjiang's total vegetation area.However,the tree blight has become a major factor affecting healthy growth of desert plants,and seriously affecting the improvement of ecological environment in Xinjiang.This study collected 40 specimen from 2 autonomous prefecture on 8 hosts,using the method of the traditional morphology and molecular biology to clear the taxonomic status of the pathogen,through this way,a search table based on morphological features was developed.The conclusions in the current study are below:(1)47 strains which collected from 8 different hosts were all belong to Ascomycota,they are also belong to 11 fungal groups,Cytospora,Diaporthe,Melanconis,Cryptosphaeria,Diatrype,Hymenopleella,Nectria of Sordariomycetes and Camarosporium,Microsphaeropsis of Dothideomycetes.(2)Hymenopleella hippophaeicola is identified as new record in China,Cytospora chrysosperma,C.sophoricola,Cryptosphaeria pullmanensis are first reported on Elaeagnus angustifolia,among which Cytospora sophoricola is first discovered on Halimodendron halodendron.Cryptosphaeria pullmanensis cause canker on the host of Tilia cordata,Diaporthe cotoneastri and Nectria dematiosa cause damage on the host of Hippophae rhamnoides,Microsphaeropsis sp.of Tamarix ramosissima,they are all the first time reported as new host records.(3)Summarize the species of fungal pathogen identification basis on the characteristics,the arrangement mode,morphological characteristics of stroma,the internal structural feature of fruiting bodies,with or without special structure(Black conceptacle and Centrum column),and the shape,color,size of conidia.The unstable colony can as the auxiliary basis to identified the fungal pathogen.(4)Using the Neighbor-joining method to structure ITS and NL single gene fragment,and construct the phylogenetic tree combine ITS ans RPB2 gene,shows that all kinds of fungus of Sordariomycetes have independent branch,indicate that multiple genetic fragments combined is beneficial to accurate indentification of fungi species.