Study On The Diversity Of Eucaryotes In Soil From Cunninghamia Lanceolata Plantation

The microbial diversity and function of soil have been greatly known by studing the soil metagenomic based on high-throughput sequencing,and this method has been widely applied to research the diversity of environmental microorganisms.Health status of Cunninghamia lanceolata plantation soil directly influences its productivity.Eukaryotes is an important factor of material circulation in soil,different groups have different functions in the soil,change their distribution could be more accurately reflect the soil fertility.In this study,by analyzing the 18S rDNA gene region of the soil metagenomic,the variation of community diversity and structure of soil microfauna and fungus which in different ecological successions(first,second,and third successions)and different ages(3,13,and 26 years)of Cunninghamia lanceolata plantations,located in Youxian County,Hunan Province,had been learned.The results showed there was a group of eukaryotic microorganism could indicate a soil health condition,and the evaluation system of soil health has been constructed.The main results were as follows:(1)The Pyrosequencing of 18S rRNA genes of soil eukaryotic.Soil metagenomic DNA was extracted using the Soil DNA kit(OMEGA),By using the 454 pyrophosphate sequencing,124019 effective sequences with an average length of 369 bp were obtained in this study,and in which there wre 94922 of highly quality sequences with an average length of 436 bp.After comparing form the SILVA database,there were 92592 sequences could be found(about 97.55%of the high quality sequence).Among the 92592 highly quality sequences,60494 sequences belong to Metazoa(about 65.34%of the high quality sequence),and 16321 sequences belong to Mycota(about 17.63%of the high quality sequence).(2)The main groups of soil eukaryotic organisms.When the genetic relatedness was 97%,the sequences of Metazoa constituted 2602 kinds of OTUs.The dominant taxonomic groups across all samples were Chordata,Annelida,Arthropoda,Nematoda,Rotifera and Platyhelminthes with each accounting for 60.8%,24.0%,7.4%,3.6%,1.5%and 1.2%of the sequences,respectively.Also the sequences of Fungi constituted 2136 kinds of OTUs.The dominant taxonomic groups were Eurotiomycetes,Sordariomycetes,Glomeromycota(unclassified group),Mucoromycotina(unclassified group),Dothideomycetes,Leotiomycetes,Pezizomycetes,Agaricomycetes and Chytridiomycota(unclassified group)with each accounting for 26.21%,12.44%,11.90%,8.25%,6.51%,5.70%,2.62%,2.30%and 2.23%of the sequences,respectively.(3)Community structure and diversity of soil eukaryotic organisms which in different ecological successions and different ages of Cunninghamia lanceolata plantations.The similarity coefficient of Jaccard both of soil metagenomic and fungus were less than 0.35 in different areas,and the community structure also showed the obvious difference among these sample areas.On the one hand the ACE and Shannon of soil metagenomic had significant difference,on the other hand the ACE,Chaol and Simpson of fungus also had significant difference.The diversity of soil eukaryotes showed that:The first ecological successions young plantations(FYC)>The second ecological successions young plantations(SYC)>The third ecological successions young plantations(TYC);The first ecological successions young plantations(FYC)>The first ecological successions mature plantations(FRC)>The first ecological successions middle age plantations(FMC).The physical and chemical properties have significantly influence on the diversity of soil eukaryotic organisms,especially in pH,bulk density and porosity.