ISHS Acta Horticulturae 695: I International Symposium on Tomato Diseases
PLANT HOST IS INDUCING DIVERSITY WITHIN RALSTONIA SOLANACEARUM STRAINS |
| Authors: | M. Elbaz, H. Kodja, J. Luisetti |
| Keywords: | bacterial wilt, botanical origin, metabolic variation, Biolog system |
| Abstract:
Ralstonia solanacearum is a complex species showing a broad variability at the infraspecific level. Many factors potentially contribute to the establishment of such a genetic and phenotypic diversity: e.g. environmental conditions, cultural management systems and farming practices. From these, host plant is of great concern. In this study, phenotypic diversity of R. solanacearum strains was assessed based on metabolic profiles. Precisely, the metabolic diversity of a set of biovar 3 strains collected either from different plant hosts in Reunion Is. or from wilted plant hosts grown in a naturally infested plot was examined. Isolates from tomato, eggplant and geranium displayed significant difference in their ability to metabolize different substrates. Further experimentation concerned a set of 75 isolates from a F3 tomato population (WVa 700 x Hawaii 7996) that were tested partially resistant to a race 3 (biovar 2) strain of R. solanacearum. A hierarchical cluster analysis was performed that led to 8 clusters. 42 isolates obtained from the F3 tomato plants were sharing similar capability to utilize carbon sources as the initial inoculum strains and clustered in two groups. The remaining 33 F3 isolates clustered into six groups and varied from the initial R. solanacearum population. This indicates that the host may be able to induce metabolic diversity within R. solanacearum. It is anticipated that genetic and pathogenic diversity within a population of R. solanacearum may be host mediated. | |
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