Premium
Direct Delivery of Inoculum to Shoot Tissue Interferes with Genotypic Resistance to Ralstonia solanacearum in Tomato Seedlings
Author(s) -
Thomas Pious,
Sadashiva Avverahally T.,
Upreti Reshmi,
Mujawar Mohammed M.
Publication year - 2015
Publication title -
journal of phytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 60
eISSN - 1439-0434
pISSN - 0931-1785
DOI - 10.1111/jph.12281
Subject(s) - inoculation , biology , petiole (insect anatomy) , seedling , sowing , ralstonia solanacearum , shoot , horticulture , bacterial wilt , genotype , agronomy , pathogen , botany , microbiology and biotechnology , hymenoptera , biochemistry , gene
Employing known susceptible and resistant genotypes and pure bacterial inoculum (0.1 OD ; 10 8 CFU/ml −1 ), five different inoculation methods were tried to assess the response of tomato genotypes to R alstonia solanacearum . This included seed‐soaking inoculation, seed‐sowing followed by inoculum drenching, or at 2‐week stage through petiole‐excision inoculation, soaking of planting medium with inoculum either directly or after imparting seedling root‐injury. Seed‐based inoculations or mere inoculum drenching at 2 weeks did not induce much disease in seedlings. Petiole inoculation induced 90–100% mortality in susceptible checks but also 50–60% mortality in normally resistant genotypes within 7–10 days. Root‐injury inoculation at 2‐week seedling stage appeared the best for early and clearer distinction between resistant and susceptible lines. The observations suggest a role played by the root system in governing genotypic resistance to the pathogen. Direct shoot inoculation is to be adopted only for selecting highly resistant lines or to thin down segregating populations during resistance breeding.