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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。
Denaturing gradient gel electrophoresis (PCR-DGGE) was used to study the characteristics of fungal community structure in vegetable soils after organic carbon and nitrogen was applied for 56 days. The results showed that there was a significant difference in the community structure of fungi between soil and organic production system in conventional production systems. The contents of microbial nitrogen in organic production system soils plus straw treatment (OS) were significantly higher than those in other treatments. According to Shannon-Wiener diversity index analysis of DGGE, the index of fungi diversity in organic production system soils (O) and after adding alfalfa (OA) was higher than that in conventional production system. However, after adding alfalfa, the diversity index The gap between organic and organic farming systems has the highest index of diversity of soil plus straw treatment (OS). Unweighted group averaging (UPGMA) cluster analysis divided conventional and organic background soils into two major groups. DGGE band sequencing and phylogenetic tree showed that most of the 35 bands were non-culturing, and the main dominant species belonged to Pyronemataceae, Pleosporaceae and Ascobolaceae. The F9 and F24 bands of pathogenic fungi Pleosporaceae were only found in conventional soils, and bands of these pathogenic bacteria were weakened by the addition of alfalfa (CA). Ascobolaceae fungi that decompose cellulose are characteristic bands of organic soils.