DNA Barcoding Research Of 41 Wood-decaying Fungi Species In Guangxi

Wood-decaying fungi are one of the most important parts of forest ecosystem.It participate in the material and energy circulation,and maintain the ecological balance of forest ecosystem.Many wood-decaying fungi are edible fungi,medicinal fungi or edible and medicinal fungi,it can also be applied to the treatment of industrial and agricultural pollutants and wastes,which has high economic value.However,wood-decaying fungi have certain dangers.Wood-decaying fungi are parasitic fungi or saprophytic fungi in trees or wood,economic and environmental damage caused.Therefore,accurate identification of wood-decaying fungi is very important.Guangxi has superior natural conditions and abundant of wood-decaying fungi.There were more than 300 species of wood-decaying fungi,among which 85 species are edible wood-decaying fungi,127 species of medicinal wood-decaying fungi and 51 species of edible and medicinal wood-decaying fungi.Now,the classification of wood-decaying fungi is dominated by morphology.However,the relatively special growth environment,the relatively large changes in morphological features and the relatively small differences of some wood-decaying fungi has some characteristics.It is difficult to carry out accurate classification and identification.It needs to use a more versatile method to assist morphological classification and identification.The development of DNA barcoding technology has effectively made up for this deficiency.Internal Transcribed Spacer(ITS)is the most commonly used analysis sequences of wood-decaying fungi.DNA barcoding was applied to taxonomy and identification of 271 specimens of wood-decaying fungi in Guangxi.The purpose of this study is to investigate the feasibility and applicability of DNA barcoding based on ITS sequences for wood-decaying fungi.DNA barcoding research and analysis were made for wood-decaying fungi under different conditions.Compared with morphological identification,if wood-decaying fungi were incomplete because they were bitten by insects or rotten,or polluted,it would affect DNA barcoding acquisition of wood-decaying fungi and further affected research and identification of wood-decaying fungi based on DNA barcoding,while the morphological difference had little impact on them.213 ITS sequences of wood-decaying fungi came from 41 species,belonging belonging to29 genuses of Ascomycota and Basidiomycota.In the results,the 41 wood-decaying fungi species showed a unique DNA barcoding.ITS sequences length of were about 550 bp to 700 bp,ITS sequences of Daldinia eschscholtzii of Ascomycota was the shortest 556 bp,ITS sequences of Basidiomycota were about 600 bp to 700 bp,and ITS sequences length of wood-decaying fungi were within a certain range,but the number of ITS sequences of some wood-decaying fungi were less and lack of persuasion.After comparison of the obtained ITS sequences of wood-decaying fungi were made BLAST comparison analysis on NCBI.It was found that the sequences with high ident and identical morphological identification Latin name could be found.However,in the case where the ident was the same,some sequences with the same Latin name ranked low,which exerted a certain effect on BLAST comparison analysis.It needs further research and analysis.Multiple comparison analysis was performed on 213 ITS sequences of 41 wood-decaying fungi species.The base composition of ITS sequences of wood-decaying fungi showed obvious bias,which conformed to the characteristics of base composition of ITS sequences.The great differences were shown among ITS sequences,which was identical to great differences in the type of wood-decaying fungi used in the research.The genetic distance analysis of Kimura 2-parameter(K2P)was performed for 213 ITS sequences of wood-decaying fungi and 41 ITS sequences of wood-decaying fungi from NCBI.The mean intraspecific distance was 0.001 and the mean interspecific distance was 0.111.These results indicated that it can distinguish most of the wood-decaying fungi.The close relatives between Microporus or the great intraspecific variation of Trametes versicolor have certain limitation.The genetic distance analysis of K2 P is performed alone and distinguishes effectively of wood-decaying fungi.A total of 254 ITS sequences were analyzed with wood-decaying fungi as out group by constructing Neighbor-joining(NJ)tree,these resulted indicated that it can distinguish most of the wood-decaying fungi.The bootstrap value is more than 74% and most of which is 99%.A few species of wood-decaying fungi mixed together in the same branch,and need to construct NJ tree about families and genuses to performed alone and distinguish effectively of wood-decaying fungi.The type of wood-decaying fungi used in the research was scattered,the species had the great differences,the total number was relatively large,and the data of some species was few.Moreover,the classification of some Polyporales was still dominated by morphology,and systematic taxonomy study was still developing.Except some genuses with single classification could form monophyletic,the branches of other genuses were disorderly.Thus,the result was only for reference.In further study and analysis some doubtful species of wood-decaying fungi,somesequences were obtained for BLAST comparison on NCBI.The classification error might exist,either few comparative data resulting in result unreliability,or absence of related data or no witness of related specimen leading to difficulty in drawing conclusions.The interspecific differences of Microporus were close relatives,the intraspecific variation of Trametes versicolor was the great differences.It needs to increase the quantity of sample and other DNA sequences to combine for further research and analysis.In the end,DNA barcoding of 41 wood-decaying fungi species was combining with morphological identification.Except other species of Microporus,wood-decaying fungi could be differentiated using BLAST analysis,K2 P genetic distance analysis and NJ tree analysis.DNA barcoding technology based on ITS sequences has feasibility and applicability in distinguishing and identifying of wood-decaying fungi,but such methods had a certain limitation.