Physiological responses of calcium-efficient and calcium-inefficient tomato genotypes to differential bacterial wilt conditions.

Bacterial wilt (BW) disease, caused by Ralstonia solanacearum, can severely limit tomato (Solanum lycopersicum) production in southern United States. Tomato genotypes display variable responses to BW disease. The physiological mechanism underlying BW resistance is not well understood. In this study, experiments were conducted to compare two tomato genotypes, PI117566 [calcium (CA)–efficient] and PI109315 (Ca-inefficient), for wilting, shoot growth, final fresh weight, and shoot Ca concentrations when inoculated with R. solanacearum. The inoculation concentration of R. solanacearum varied from 0 to 108 colony forming units/ml. Genotype PI109315 appear to be more BW-resistant compared with genotype PI117566 under sufficient Ca conditions. Furthermore, we found that genotype PI109315 had greater shoot growth and final fresh weight than genotype PI117566. These findings implied that Ca-efficient tomato genotypes may not play a key role in BW resistance of tomato under sufficient Ca conditions because Ca effic...