海南岛胡椒地穿刺巴斯德芽菌鉴定与多样性分析

Identification and diversity analysis of Pasteuria penetrans on pepper in Hainan Island

穿刺巴斯德芽菌(Pasteuria penetrans)是根结线虫(Meloidogyne spp.)的专性寄生菌,且是研究最多的线虫天敌细菌之一。胡椒作为海南的主要经济作物之一,根结线虫发病率较高。前期的研究发现,在海南岛胡椒中较易分离到P.penetrans。结合形态学和16S rRNA序列分析的方法,着重对海南岛6个市县共13个胡椒园进行P.penetrans资源鉴定发现,在经筛选获得的33个具代表性巴斯德芽菌克隆中,32个克隆子被鉴定为P.penetrans,而克隆子tf-1与P.penetransT(AF077672)的相似性仅为97.7%,且在发育树上处于独立分支,可能为巴斯德芽菌属的一个新种。聚类分析结果发现,海南岛存在较丰富的P.penetrans资源,但在不同的地理区域内没有发现明显的种内地域特异性。

Pasteuria penetrans is an obligate parasite in root-knot nematodes （Meloidogyne spp.）. Pepper is one of the main economic crops in Hainan Island and the incidence of root-knot nematode diseases on pepper is fairly high. Based on the previous studies, P. penetrans resources are easier to be discovered on pepper than other plants in Hainan Island. Through the combination of morphological identification and 16S rRNA gene sequence analysis, the Posteuria spp. resources from 13 pepper fields located in six cities of Hainan Island were investigated and identified. 33 representative Pasteuria clones were screened out, and 32 of them were identified as P. penetrans. Though the clone tf-1 was closely related to P. penetrans T（AF077672）, the sequence similarity was only 97.7% and formed a single branch in the phylogenetic tree, which suggested that tf-1 might be a novel species in the genus Pasteuria. The phylogenetic analysis showed that there were abundant P. penetrans resources in Hainan Island, but no obvious geographic specificity existed in distinct regions within the P. penetrans species.