| 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 Pasteuria 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. penetransT(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. |
