Screening of wild accessions resistant to gray mold ( Botrytis cinerea Pers . ) in Lycopersicon Egashira, H . , Kuwashima, A . , and Imanishi, S . Faculty of Agriculture, Yamagata University, Tsuruoka 997 - 8555, Japan 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 and there are very few reports about resistant materials in tomato cultivars and wild accessions (Urbasch 1986, Chetelat and Stamova, Eucarpia Tomato 97, unpubl . ) . 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 were performed .   Leaflets of the sixth compound leaf from the shoot apex, and 5 cm - stem - segments were used for the leaflet and stem bioassays . Conidial suspension with a density of 1 ´ 10 6 conidia / ml was inoculated onto the center of a leaflet using a bunch of sewing needles and onto the cut surface of a stem segment . Inoculated leaflets and stem - segments were incubated at 20 ° C under humid and 16 - h photoperiod conditions for three days . The total numbers of leaflets and stem - segments inoculated were five to twenty and seven to nine per accession, respectively . Data were analyzed using GLM procedure and its REGWQ (Ryan - Einot - Gabriel - Welsch) option of SAS Ò . 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 leaflets of LA2745, no lesion was observed even more than two weeks after the conidia inoculation . LA2745 is thought to be a promising material for breeding gray - mold resistant cultivars . Literature cited: Urbasch I . 1986 . Resistenz verschiedener Kultur - und Wildtomatenpflanzen ( Lycopersicon spp . ) gegenuber Botrytis cinerea Pers . J . Phytopathology . 116: 344 - 351 .