两种不同生境羊草根际土壤细菌群落多样性与环境因子的研究

Study on Bacterial Community Diversity and Environmental Factors in Rhizosphere Soil of Leymuschinensis

本试验以羊草(Leymus chinensis)为优势种的草甸草原为研究对象,旨在探讨两种不同样地(样地1为原生态未扰动处理,样地2为重度退化后人工补播扰动处理)土壤条件下土壤微生物群落结构、微生物多样性及微生物间互作效应的差异。结果表明:变形菌门(Proteobacteria)、酸杆菌(Acidobacteria)、放线菌门(Actinobacteria)这3个门是该地区羊草根际土壤细菌优势群落;速效氮、速效钾对细菌群落结构影响较大;土壤pH在一定阈值范围内与羊草根际土壤细菌多样性极显著相关(P<0.01);土壤有机质与羊草根际土壤细菌群落相对丰度、多样性、菌间互作显著正相关;土壤交换性钠离子含量与羊草根际土壤细菌群落多样性显著负相关;人工补播后的羊草根际土壤微生物间互作与未干扰生境下相比明显减弱。

This study aims to explore differences in soil microbial community structure,microbial diversity,and interactions among microbes between a natural-undisturbed meadow steppe and an artificially reseed degenerated meadow steppe.The results showed that Proteobacteria,Acidobacteria and Actinobacteria were the dominant bacterial communities in the rhizosphere soil of Leymus chinensis in the region;Available nitrogen and available potassium had a big impact on the bacterial community structure.Soil pH was significantly related to bacterial diversity in the rhizosphere soil of Leymus chinensis within a certain threshold range(P<0.01);Soil organic matter was significantly positively related to the relative abundance,diversity,and interbacterial interactions of the bacterial community in the rhizosphere of Leymus chinensis.The soil exchangeable sodium ion content was significantly negatively related to the bacterial community diversity in the rhizosphere of Leymus chinensis.The inter-microbial interactions in the rhizosphere soil of Leymus chinensis after artificial reseeding were significantly weakened comparing with those in the undisturbed treatment.