Characterization of population dynamics and diversity of Ralstonia solanacearum populations isolated from flue-cured tobacco in North Carolina. M. L. KATAWCZIK (1), A. Mila (1)
(1) North Carolina State University, Raleigh, NC, USA
Phytopathology 98:S79

Abstract: Bacterial wilt (BW), caused by Ralstonia solanacearum, is a serious vascular disease on members of the Solanaceae family including tobacco. In 2007 in North Carolina a total of six naturally infected fields with BW were sampled. On two of these fields, there were on-farm trials, where 30 flue-cured tobacco varieties were planted, and on four farms either K 326 or K 346 planted. Fifty-two isolates of Ralstonia solanacearum were obtained from flue-cured tobacco varieties K 326, K 346, K 394, and Sp168. From the four varieties, two (K 326 and K 394) have low whereas K 346 and Sp 168 have moderate to high resistance to BW. These varieties were chosen to determine if a certain variety selected for isolates of R. solanacearum with different levels of aggressiveness or pathogenicity. The sampling method also allowed for comparisons of isolates from the same variety between fields to investigate diversity among locations. Population dynamics and diversity were assessed by comparing race, biovar, pathogenicity, hypersensitivity response and rep-PCR fingerprints using BOX, REP, and ERIC primers. Information from this study will be used as a base to compare the diversity of R. solanacearum populations across North Carolina and to understand the variability within a single field when different varieties or a single variety are used.