碳氮有机物料对有机菜田土壤真菌多样性影响的模拟试验

利用变性梯度凝胶电泳法(PCR-DGGE),研究了施入不同碳氮有机物料56d后,有机生产系统菜田土壤真菌群落结构的特征。结果表明,常规生产系统土壤和有机生产系统土壤的真菌群落结构有明显差异。有机生产系统土壤加秸秆处理(OS)的微生物氮含量显著高于其他处理。由DGGE图谱Shannon-Wiener多样性指数分析得知,有机生产系统土壤(O)以及加入苜蓿处理后(OA)的真菌多样性指数大于常规生产系统土壤,但是加入苜蓿后两者之间多样性指数的差距有缩小趋势,有机生产系统土壤加秸秆处理(OS)多样性指数最高。非加权组平均法(UPGMA)聚类分析将常规和有机背景土壤分为2大族群。DGGE条带测序和系统进化树表明,35个条带的近缘种大部分为非培养真菌,主要优势菌群归属为Pyronemataceae、Pleosporaceae和Ascobolaceae。致病真菌Pleosporaceae的F9和F24条带仅存在于常规土壤,经过添加苜蓿改善后(CA),这些致病菌群条带减弱。具有分解纤维素功能的Ascobolaceae真菌为有机土壤的特征性条带。

Simulation of Fungal Community Structure Diversity with Carbon and Nitrogen Organic Materials Treatments in Organic Vegetable Soil

PCR-DGGE method was used to investigate effect of different carbon and nitrogen organic materials on fungal community structure of organic production systems vegetable soil.Results show that fungal community structure of conventional and organic production system soil are different significantly.The microbial biomass nitrogen of organic production system soil with straw (OS) was significantly higher than other treatments.By analyzing the Shannon-Wiener diversity index,fungal community structure diversity of conventional production systems soil (C) and conventional production systems soil with alfalfa (CA) are lower than organic production systems soil (O) and organic production systems soil with alfalfa (OA),but the diversity between them tends to be convergent after adding alfalfa.And the diversity index of organic production systems soil with straw (OS) is the highest.Conventional and organic production systems soils are divided into two ethnic clusters by unweighted group average method (UPGMA).DGGE band sequencing and phylogenetic tree show that the 35 closely related species are largely uncultured fungi,main species are attributed to Pyronemataceae,Pleosporaceae and Ascobolaceae.The fungi band F9 and F24 of pathogens Pleosporaceae only exist in conventional soil,after alfalfa improving,these bands (CA) of pathogen population reduce significantly.The fungi attributed to Ascobolaceae only exist in organic soil,which can break down cellulose.