Endophytic Colletotrichum Species Diversity Study Of Ageratina Adenophora In Yunnan

Species of Colletotrichum are important pathogens,endophytes,and saprobes on a wide range of plant hosts,which can cause such as anthracnose,postbloom fruit drop,tear stain and stem-end rot on fruit,or as wither-tip of twigs,either as agents of pre-or post-harvest infections.Ageratina adenophora is one of the most serious alien invasive plant,investigating the species diversity of highly enriched Colletotrichum associated with Ageratina adenophora,which can provide a theoretical basis for understanding the invasion mechanism of Ageratina adenophora and the control of anthracnose.We investigated the species diversity of Colletotrichum associated with Ageratina adenophora from 14 sample area of Yunnan(Cangyuan,Eshan,Gengma,Kunming,Midu,Nanhua,Nanjian,Ninger,Simao,Ximeng,Yuanjiang,Yunxian and Zhutang),A total of 263 strains were isolated.Based on the glyceraldehyde-3-phosphate dehydrogenase(GAPDH)gene encoding sequences,a subset of 17 representative isolates were selected for multigene phylogenetic analysis,further analysis based on eight genes region(ACT,CAL,CHS-1,GAPDH,GS,HIS3,ITS,TUB2)and morphological characteristics,combined Ap Mat and GS sequences were used to analysis 176 strains C.gloeosporioides species.There were 23 species identified in 263 strains,with five new species,C.nanhuaensis,C.ningerensis,C.yuanjiangensis,C.yunlongensis,C.yunxianensis.18 prevalent species,C.boninense,C.brevisporum,C.cangyuanensis,C.citricola,C.cliviae,C.fioriniae,C.fructicola,C.gigasporum,C.gloeosporioides,C.henanense,C.jasmini-sambac,C.jiangxiense,C.kahawae subsp.ciggaro,C.kahawae subsp.kahawae,C.karstii,C.nymphaeae,C.siamense,C.spicatum.Among this species,C.nanhuaensis,C.yuanjiangensis,C.yunlongensis,C.yunxianensis,C.cangyuanensis,C.fructicola,C.gloeosporioides,C.henanense,C.jasmini-sambac,C.jiangxiense,C.kahawae subsp.ciggaro,C.kahawae subsp.kahawae,C.siamense belong to C.gloeosporioides species complex.C.boninense,C.citricola,C.karstii,C.spicatum belong to C.boninense species complex.C.fioriniae,C.nymphaeae belong to C.acutatum species complex.C.gigasporum belong to C.gigasporum species complex.C.brevisporum and C.cliviae doesn't belong to any species complex.With the addition of the five new species was identified in the previous research,there were 28 species of Colletotrichum in Ageratina adenophora,which showed the species diversity of the endophytic Colletotrichum.In addition to the new species,the rest of 23 species of Colletotrichum isolated from this experiment were also reported for the first time from the Ageratina adenophora.In addition to Midu,A total of 176 strains of C.gloeosporioides complex species were isolated from the rest of 13 sampling area,indicating that this complex species is widely distributed geographically.In order to identify this complex species further,in the phylogenetic analysis we combined the loci between Apn2 and Mat1-2-1(Ap Mat)and glutamine synthetase(GS)to resolve the species in the C.gloeosporioides species complex,all species could be delimited.Compared with other used loci,the Ap Mat and GS marker provides superior phylogenetic information.Because it provides a better resolution on the clades,we therefore recommend acombination of Ap Mat and GS as an effective way of identifying species in the C.gloeosporioides species complex.The separation frequency of endophytic Colletotrichum increased with the extension of invasion,and it was easier to isolate the Colletotrichum in the area of 80 years after the invasion of the Ageratina adenophora than in the area of 50 years.