中文摘要：

利用细菌的通用引物扩增江西余江县高产水稻土红壤细菌总DNA和平板培养细菌混合总DNA的16S rDNA基因片段，在此基础上分别建立两种16S rDNA文库（文库a和文库b）。从两个文库中各随机挑选100个克隆，扩增出阳性克隆中的插入片段后选用Hha I和Rsa I两种四碱基酶进行ARDRA（amplified rDNA restriction analysis）分析。统计比较分析发现，文库a的Shannon-Wienner指数、Simpson指数、丰富度、均一度分别为4．432、0．987、18．885和0．973，均高于文库b中相应的多样性参数（分别为2．271、0．758、5．736和0．501），即平板培养方法所展现的细菌群落结构多样性低于土壤中原始的多样性。结果表明，传统培养方法存在着很大的局限性，必须结合新的分子生物学技术手段才能更全面完善地认识土壤微生物群落结构多样性，以期充分利用其中丰富的微生物资源。

英文摘要：

The objective of this study was to compare the diversity of the cultivable bacteria with the diversity of the total bacterial population in soil. Two 16S rDNA libraries, library a and library b, were constructed with DNA extracted directly from soil and cultivable bacteria derived from red soil in Jiangxi. About 100 positive clones selected randomly from each library were investigated by ARDRA （amplified rDNA restriction analysis）. After PCR amplification of insert fragments, restricted digestion of the PCR products were carried out with two restriction enzymes, namely Hha and Rsa. The statistic data showed that, Shannon-Wienner index, Simpson index, Richness and Evenness of library a were 4.432, 0.987, 18.885 and 0.973, and all of them were higher than those of the counterparts of library b which were 2.271, 0.758, 5.736 and 0.501. It indicated that traditional cultivation methods have its limitations and difficulties in exploring the diversity and potential of microbial communities. But associate with the new molecular technology, we can analyze the diversity of the microorganism community, evaluate the ecology environment and exploit the microorganism gene resources.