Resistance of Solanum Species to Phytophthora Infestans evaluated in the Detached-Leaf and Whole-Plant assays

The reaction of 82 tomato genotypes belonging to 8 solanum and a lycopersicon species against phytophthora infestans causing late blight was determined using detached-leaf and whole-plant assays. none of the test genotypes was immune or highly resistant. of the 82 commercial and wild genotypes only tms-2 (male-sterile and characterized by indeterminate growth) belonging to lycopersicon esculentum was resistant with severity index of 2.4 in the detached-leaf assay on 0-5 scale (where 5 was highly susceptible) and percent disease index (%di) of 23.3% under the whole-plant assay. among the remaining genotypes,41 were susceptible and 40 were highly susceptible under the detached-leaf assay,while 18 were susceptible and 63 were highly susceptible under the whole-plant assay. however,there was a significant difference in %di for genotypes under the whole-plant assay. the response of whole-plants to inoculation with p. infestans in the detached-leaf assay was similar in all cases. the overall screening results indicate that tms-2 is a good source of resistance and it can be useful for the development of tomato hybrid cultivars resistant to late blight.