Occurrence of Ralstonia solanacearum Race 3 biovar 2A in Mauritius
| MSI10P4487 | |
| Saumtally, A. S. Khoodoo, M. H. R. Ganoo, E. S. | |
| Occurrence of Ralstonia solanacearum Race 3 biovar 2A in Mauritius | |
| Proceedings of the 12th International Conference on Plant Pathogenic Bacteria, June 7-11, 2010, Parc des Expositions et des Congrès de Saint-Denis, Ile de la Réunion: Programme, Abstracts, List of participants | |
| book chapter | |
| 2010 | |
| p. 154 | |
| ICPPB | |
| Abstract only | |
| En | |
| En | |
| During October 2005, an outbreak of bacterial wilt occurred in potato varieties Atlantic, Delaware and Spunta at Britannia, in the south of the island. Symptoms on tubers were atypical of what is commonly observed with Ralstonia so/anacearum race 1 biovar 3 and consisted of profuse bacterial exudates, oozing from the eyes of tubers and extensive degradation of vascular rings. The isolated bacterium was identified as R so/anacearum race 3 biovar 2 of Andean phenotype Bv 2-A, a first report in Mauritius (1). This was confirmed by CABI Identification Service, UK. Isolates were found to metabolise the dissacharides maltose, lactose and cellobiose but not trehalose and the hexose alcohols dulcitol, mannitol and sorbitol. The pathogen is now routinely identified by PCR using race 3-specific primers 630/631 (2). The bacterium was recovered from soil samples and the alternative hosts nightshade (Solanum americanum), wild cherry tomato (Lycopersicon pimpinellifolium) and oxalis (Oxalis latifolJ) in 2006 at the first outbreak site. New outbreaks were further recorded in 2006 at Labourdonnais (north). In 2008, it was found at Belle Vue, Riche Terre, (north) and Medine (west) on potato and tomato. In the same year, it was detected in soil collected at Pamplemousses (north). In 2009, the pathogen was not observed in field samples. However, it was detected in fresh local potato tubers on sale at the market indicating that it was still present. The spread of race 3 of R so/anacearum could have a negative impact on potato cultivation and seed production in Mauritius. Due to extensive rotting of tubers, it is more damaging than race 1. In contrast to the latter, race 3 is able to thrive at a lower temperature, posing a risk to potato cultivation which takes place during the cooler months of the year in Mauritius. The pathogen has been found to survive well for over four months in infected potato tubers undergoing cool storage at 2-4 QC. The mode of entry of the new race is not known but it is suspected to have been introduced through imported ware potato as detected in 2007. Molecular studies of the population of race 3 suggest possibly different introductions as two genetically diverse groups have been characterized (3). | |
| potatoes diseases bacterial wilt Ralstonia solanacearum variations | |
| Mauritius | |
| Potatoes: Diseases and disease management | |
| Bacterial diseases: Bacterial wilt | |
| 2010-08-06 | |
| En | |
| PATH | |
| CAT | |
| PATH |