Screening of wild accessions resistant to gray mold (Botrytis cinerea Pers.) in Lycopersicon

Tomato gray mold (Botrytis cinerea Pers.) is a common disease worldwide, and often causes serious production loss by infecting leaves, stems, flowers and fruits. Presently, no resistant cultivars are available. To find new breeding materials for gray mold resistance, assessment for resistance of the leaflet and stem in six tomato cultivars, 44 wild tomato accessions and a Solanum lycopersicoides accession was performed. Although no correlation was observed (r=−0.127^ns) between resistance of the leaflet and the stem, L. peruvianum LA2745, L. hirsutum LA2314 and L. pimpinellifolium LA1246 showed high resistance both in the leaflet and in the stem. Particularly, in the leaves of LA2745, no lesions were observed even more than two weeks after the inoculation with conidia, and F1s between a cultivated tomato and LA2745 also showed high resistance as observed in LA2745. From these results, LA2745 is thought to be a promising material for breeding gray-mold resistant cultivars.