中文摘要：

为明确不同土壤条件对甘蔗内生固氮菌多样性的影响,对分别种植在红壤土和水稻土的4个甘蔗品种的内生固氮菌进行分离和鉴定,并利用数学生态学方法分析不同来源内生固氮菌的多样性。结果表明,从红壤土的甘蔗组织中分离筛选获得23个内生固氮菌株,它们在基于16S r DNA序列分析结果上属于9个不同的菌属;而从水稻土的甘蔗组织中获得59个内生固氮菌株,分类上属于19个不同的菌属。群落生态学分析结果显示,来源于水稻土的甘蔗内生固氮菌的群落丰富度指数（dma）、多样性指数（H＇）以及均匀度指数（Jsw）均明显高于红壤土,表明水稻土条件下的甘蔗内生固氮菌群落结构相对复杂、稳定和均匀;而相同土壤条件下4个甘蔗品种间的内生固氮菌丰富度指数和多样性指数差异并不明显。本研究结果反映了土壤生态条件是影响甘蔗内生固氮菌多样性的重要因子。

英文摘要：

In order to elucidate the effect of soil condition on the diversity of endogenous nitrogen-fixing bacteria of sugarcane, the endogenous nitrogen-fixing bacteria was isolated and identified from 4 different sugar cuhivars which were grown in red soil and paddy soil, respectively, and the biodiversity were analysed by using the mathematical ecology method. Results showed that the twenty-three sugarcane endogenous nitrogen-fixing bacteria isolates from the red soil belonged to 9 genus ; and the fifty- nine sugarcan endogenous nitrogen-fixing bacteria isolates from paddy soil belonged to 19 genus. The mathematical ecology ana- lyses showed that the community richness index （dma） , Shannon-Wiener index （H＇） and evenness index （Jsw） of sugarcane endogenous nitrogen-fixing bacteria from paddy soil were significantly higher than that from red soil, while all the indexes among different sugarcan cultivars which grown in the same soil condition showed no significant difference. This study inferred that the soil ecotype is important factors that affect the diversity of sugarcane endogenous nitrogen-fixing bacteria.