玉龙雪山自然保护区寒温性针阔混交林腐殖质层和土壤表层线虫群落结构差异

Difference of soil nematode communities between the humus and soil surface layer in the cold temperate coniferous and broadleaved mixed forest of Yulong Snow Mountain Nature Reserve,Yunnan,China

采用高通量测序的方法,对位于云南省丽江玉龙雪山自然保护区20 hm^2寒温性针阔混交林中腐殖质层和土壤表层(0~10 cm)线虫群落结构的差异进行了研究。共获取测序序列5744582条,注释后获得44科线虫。腐殖质层线虫有37科,其中垫刃科(18.1%)为优势类群,营养类群以食细菌、食真菌和植食性线虫为主;土壤表层线虫有41科,单齿科(45.4%)为优势类群,捕食性线虫具有最高的相对多度。虽然在操作分类单元(OTU)水平上两个生境线虫群落的α多样性(Shannon、Simpson和Chao1指数)无显著性差异,但在科水平上,腐殖质层线虫群落的α多样性指数显著低于土壤表层;两个生境的β多样性有较大差异,其中腐殖质层Cody指数低于土壤表层,而Sorensen非相似性指数相反。非度量多维标度(NMDS)分析表明,土壤表层线虫群落内部结构差异大于腐殖质层。

A high-throughput sequencing approach was used to differentiate the nematode communities in the humus and soil surface layer(0-10 cm)in 20 hm^2 plot located in the cold temperate coniferous and broadleaved mixed forest of Yulong Snow Mountain Nature Reserve,Lijiang,Yunnan.A total of 5744582 sequences were obtained,which were further annotated to 44 nematode families.In the humus layer,37 families were recorded,with Tylenchidae(18.1%)being the most dominant family.For trophic groups,bacterivorous,fungivorous and herbivorous were predominant.The soil surface layer had 41 families,with Mononchidae(45.4%)being the most dominant family.The relative abundance of predatory nematode was highest in the soil surface layer.There was no significant difference in theαdiversity indices(Shannon,Simpson and Chao1 index)of nematode communities at the OTU level between two habitats.At the family level,however,αdiversity of nematode community in the humus layer was significantly lower than in soil surface layer.βdiversity of the nematode community was significantly different in the two habitats,with lower Cody index but high Sorensen non-similarity index in the humus habitat.Results of non-metric multidimensional scaling(NMDS)analysis showed that the internal structure difference of nematode community in the soil surface layer was higher than that in the humus layer.