Study On The Dendrocola Mycoflora In Needles Of Spruce On Er-lang Mountain

This thesis focuses on the research of the dendrocola mycoflora in needles of Spruce on Er-lang Mountain.Two methods were used to isolate dendrocola mycoflora in needles of various ages and canopy from various altitudes in various months,and 168 strains were obtained,among which 83 strains were obtained from the group of surface disinfection,128 strains were obtained from the group of none disinfection and 43 strains were obtained from both groups.87 strains were identified by morphology,and only 52 strains were identified exactly which belong to 17 generas, that is Chaetomium,Pestalotopsis Steyaert,Pithomyces,Spegazzinia,Aspergillus,Lophodermium,Penicillium,Nigrospora,Sporormiella,Monilia,Phomopsis,Papularia,Basipetospora,Verticillium,Preussia,Dictyoarthrinium,Tricladium. It modifies the medium formula to culture inducing sporogenesis to the 81 isolates which have not sporulated except 5 Pestalotopsis strains which do not sporulate on PDA sporulates,no sporing structure nor spore are found in other isolates.The 24 isolates which have high positive rate but have no spores or only have conidia with no sporing structure were identified by molecular method.By the improving method of benzyl chloride DNA extraction,high -quality DNA of 24 isolates were obtained.The ITS regions of rRNA gene were amplified by the polymerase chain reaction(PCR) with the fungi general primers ITS₁ and ITS₄.The amplified fragments,about 540bp to 640bp in length,were purified,cloned to pUCm-T vector and transformed into the CaCl₂-competent E.coli JM109 host.ITS fragments inserted to pUCm-T vector were sequenced and compared with those in GenBank.The homology tree was established by the sequence comparison.The results showed that these 23 isolates,which beloned to ten generas and four species: Kabatina sp..Two of the islolates,Rhizosphaera kalkhoffii seems like the same with pathogen of spruce needle loss,which was reported by overseas.It was suspected as pathogen of disease in needles of Spruce on Er-lang Mountain.Coenology was studied through statistical analyze of positive rate of the fungi on needles of spruce,and combining the basic principles and analysis methods of bionomics.The result showed that there was definitely rules on species compse and community variety by some degree.The result of analyzing the species from the fungi on needles of Spruce shows:the variety and number of the fungi on needles obtained from two surface antisepsis methods have the same characteristic.The species of fungi on lower crown layer is most,lesser in upper layer and least in middle layer. The species and quantity of the fungi in needles increased with increasing of needle ages,and there was no obvious differences on middle canopy,but there was a a trend that that of 3 years elder is bigger that that of the younger.Basing on the isolation rate of all the fungi in needles of Spruce,the species obtained from surface antisepsis were less that with no antisepsis.The species of fungi obtained in different months is that: July and Sepetember had the most,Marth and May had second most,November was relatively less and Janurary had the least.As for the altitudes,the changes of species of needle dendrocola fungi was just like "U",that was,species from 2680m had the the most species,and decreased in two ends,2880 has the least.The analysis of diversity of the needle dendrocola mycoflora shows:the diversity and evenness of the fungi on needles of Spruce in July and September was the most,and that of November and Januarury was the lowest.The diversity of the needle dendrocola mycoflora from altitudes 2680 was the highest and that of 2880 was the lowest.The trends of evenness of the fungi on needles in different altitudewas 2580m＞2680m＞2780m＞2480m＞2880m.