水稻纹枯病拮抗细菌的种群分布及其生物多样性研究

STUDY ON THE POPULATION DISTRIBUTION AND BIODIVERSITY OF ANTAGONISTIC BACTERIA AGAINST Rhizoctonia solani

通过对从菲律宾Ｌａｇｕｎａ 省水稻植株上分离获得的７００ 个细菌菌株进行离体与生物测定发现：在水稻生态系统中，存在着大量格兰氏阴性、非致病性、对纹枯病有拮抗作用的细菌。用Ｂｉｏｌｏｇ 微板的方法鉴定了１９５ 个细菌菌株的种类。在１４７ 个格兰氏阴性菌株中有１４ 个属３９ 个种，在４８ 个格兰氏阳性菌株中有８ 个属１３ 个种。在１９５ 个被测菌株中最为常见的种是Ｓｔｅｎｏｔｒｏｐｈｏｍｏｎａｓ ｍａｌｔｏｐｈｉｌｉａ ，Ｐｓｅｕｄｏｍｏｎａｓ ａｅｒｕｇｉｎｏｓａ 和Ｐｓｅｕｄｏｍｏｎａｓ ｐｕｄｉｔａ ，并且上述３ 个种内具有拮抗性能较强菌株的比例相当高。因此，这３ 个种的细菌对水稻病害的生物防治很有潜力。用ＰＣＲ 的方法分析上述３ 个细菌种部分菌株的生物多样性，结果表明：同一属不同种菌株之间的ＤＮＡ 带谱有一定的交叉；不同属之间的ＤＮＡ带谱的差异明显大于种之间的差异。

Seven hundred bacterial strains isolated from leaf and sheath of rice plants of Laguna province, Philippines were tested in vitro.Results showed that there were a great number of bacteria that were Gram negative、nonpathogenic and antagonistic to Rhizoctonia solani. Among 195 bacteria strains identified,147 were Gram negative,belonging to 14 genera 39 species, and 48 were Gram positive belonging to 8 genera 13 species. Stenotrophomonas maltophilia , Pseudomonas aeruginosa and Pseudomonas pudita were the predominant species possessed large amount of antagonistic strains. The biological diversities of partial strains of above species were analyzed by rep-PCR. Results showed that DNA bands of different species from same genus crossed each other at sometime; the differences of DNA bands were greater between genus than that between species.