氮肥缺失对旱地土壤细菌群落多样性的影响

RFLP analysis on the impact of microbial diversity of dry land soils without nitrogenous fertilizer

本文旨在研究氮肥缺失对旱地土壤细菌群落多样性的影响。采用直接提取土壤微生物总DNA的方法,对不施肥（CK）、适量施肥（F1）、和缺氮施肥（F2）3种不同施肥水平土样DNA进行提取,扩增细菌16S rDNA基因片段,建立克隆文库。用限制性内切酶HhaI和RsaI进行PCR-RFLP分析,分别得到146、187、11个酶切类型。采用α多样性的测度对试验结果进行分析统计结果表明,不同处理间土壤细菌的多样性（H′、Ds和Dg）和物种丰富度（dMa、R2和E）均为F1〉CK〉F2;λ、dMa、E和H′指数在不同施肥处理间的变异系数达到56.96%-163.1%,尤其Simpson指数λ是非常敏感的指标,处理间的差异最大,表明氮肥缺失严重影响土壤细菌群落多样性,合理施肥有利于土壤细菌的多样性。

The impact of the absence of nitrogenous fertilizer on bacterial diversity in soil had been explored in this study.Total genome DNA of soil microorganism was extracted by a direct method from three soil samples of different fertilizing treatment which are CK without fertilizer,F1 with proper fertilizer and F2 without nitrogenous fertilizer.The 16S rDNAs of the extracted DNA were amplified using bacterial universal primers and then set relevant clone libraries.Using PCR-RFLP based on restriction endonuclease Rsa I and Hha I,simultaneously,restriction endonuclease types of these samples were got as 146,187 and 11 after counting.All the data was analyzed by α diversity measurement indices,which showed the identical order of diversity（H′,Ds and Dg）and richness（dMa,R2 and E）between different treatment as F1〉CK〉F2.The coefficient of variation of indices λ,dMa,E and H′ between different soil samples is 56.96%～163.1%,especially for index λ,with the greatest sensitivity,had the biggest difference between three different soil samples,suggesting that the bacterial diversity in soil was influenced seriously under absence of nitrogenous fertilizer,and proper fertilizer was positive to them in contrast.