Study On Genetic Variation Pattern Of Isaria Farinosa In Yunnan

Isaria farinosa is a widely distributed entomogenous fungus in the world.Based on the environmental and Cordyceps resources diversity of Yunnan,I.farinosa and related species in genera Isaria and Beauveria were investigated and collected in the present study,using morphology,molecular sequences,chemical components and antioxidant ability as indexes.The genetic variation pattern was analyzed in I.farinosa populations in Yunnan,and the main results were as follows:1.farinosa resource was plentiful in Yunnan.Its diversity of habitat indicated extensive adaptation.Its host included insects,fungi and soil.I.farinosa The habitat data of I.farinosa in China was statistic.This investigation attempted to provide the basic information of habitat,host and geography of I.farinosa for ecological study.Observed morphology of colony,growth rate,mycelium yield,Phialospore and spore size in I.farinosa and related species,the intro-specific differentiation also was constructed.From the morphology,different species in genera Isaria and Beauveria could be distinguished-Morphology characteristics still was effective in classification.The morphology indexes variable coefficient(CV value)were between 0.02 and 0.79.while the mycelium yield has maximum CV value than other indexes.It should be used as a chosen characteristics for produce I.farinosa.Morphology was different in geographic populations of I.farinosa.And there were differentiation between populations and individuals.The size of phialospore and spore were stabilized in.I farinosa.The morphology differentiation had no correlation with geographic distance.Using 18S rDNA,28S rDNA,EF-1?,RPB1 and RPB2 as molecular markers,the genetic characteristics was studied in I.farinosa in Yunnan.The phylogenetic analysis showed there were distance between species,and these 5 genes all could be used to distinct species in genera Isaria and Beauveria.There was obvious genetic variation and differentiation in I.farinosa based on 18S rDNA,28S rDNA,EF-1?,RPB1 and RPB2.While the Fsts were 0.18457,0.7403,0.47223,0.47223 and 0.23795,and the Nm values were 0.04,0.09,0.23,0.23 and 0.80,respectively.There were obvious genetic differentiation in I.farinosa populations based on the 5 genes.These genes of I.farinosa had low gene exchange in Yunnan.The I.farinosa showed great genetic diversity and differentiation in Yunnan.The heat shock proteins 70 and 90 were cloned and analyzed in I.farinosa.For IFHsp70,the sequence was 2158 bp,and its ORF(open reader frame)was 1962 bp coding 653 amino acid.For IFHsp90,the sequence was 2144 bp,its ORF was 2104 bp coding 700 amino acid.Applied Hsp70 and Hsp90 as molecular markers,we constructed phylogenetic trees of I.farinosa with its related species in Yunnan.These species could be distinct in the phylogenetic trees.There was genetic differentiation in Hsp70 and 90 in I.farinosa.Their Fsts both were about 0.17,and values were 1.22 and 1.24.There was slight gene exchange in I.farinosa populations.This study showed the two genes were useful molecular markers that could be explored to used in genetic variation and phylogenetic study.I.farinosa had high nucleoside components and could be explored and utilized compared with Cordyceps militaris.Its adenosine,uridine and guanine contents were 1034.33,1010.07 and 887.56?g/g,respectively.Nucleoside components varied in I.farinosa populations and individuals in Yunnan.There was differentiation among geographic populations,and the population from Xianggelila county has highest adenosine content(6596?g/g)than other 9 populations.The results showed there was no cordycpin in I.farinosa.For antioxidant activity,I.farinosa also had potential as well as its related species.