Phylogenetic relationships of Ralstonia solanacearum species complex strains from Asia and other continents based on 16S rDNA, endoglucanase, and hrpB gene sequences

Springer Science and Business Media LLC - Tập 71 - Trang 39-46 - 2005
Joselito E. Villa1, Kenichi Tsuchiya2, Mitsuo Horita3, Marina Natural4, Nenita Opina5, Mitsuro Hyakumachi6
1United Graduate School of Agricultural Science, Gifu University, Gifu, Japan
2Division of Microbiology, National Institute for Agro-Environmental Sciences, Tsukuba, Japan
3National Agricultural Research Center for Hokkaido Region, Sapporo, Japan
4Department of Plant Pathology, UPLB, College, Laguna, Philippines
5Institute of Plant Breeding, College, Laguna, Philippines
6Laboratory of Plant Disease Science, Gifu University, Gifu, Japan

Tóm tắt

The 16S rDNA, endoglucanase, and hrpB genes were partially sequenced for Asian strains of Ralstonia solanacearum spp. complex, including 31 strains of R. solanacearum and two strains each of the blood disease bacterium (BDB) and Pseudomonas syzygii. Additional sequences homologous to these DNA regions, deposited at DDBJ/EMBL/GenBank databases were included in the analysis. Various levels of polymorphisms were observed in each of these DNA regions. The highest polymorphism (approximately 25%) was found in the endoglucanase gene sequence. The hrpB sequence had about 22% poly-morphism. The phylogenetic analysis consistently divided the strains into four clusters, as distinctly shown on the phylogenetic trees of 16S rDNA, hrpB gene, and endo-glucanase gene sequences. Cluster 1 contained all strains from Asia, which belong to biovars 3, 4, 5, and N2. Cluster 2 comprised the Asian strains of R. solanacearum (as biovars N2 and 1) isolated from potato and clove, as well as BDB and P. syzygii. Cluster 3 contained race 3 biovar 2 strains from potato, race 2 biovar 1 strains from banana, and race 1 biovar 1 strains isolated from America, Asia, and other parts of the world. Cluster 4 was exclusively composed of African strains. The results of the study showed the distribution and diversity of the Asian strains, which are present in three of the four clusters. The similarity of Asian strains to those in the other regions was also observed.