Author : Khin Lay Lwin

Summary : Solanum torvum variety from three locations, five commercial eggplant varieties, and four tomato varieties were identified against bacterial wilt and the graft compatibility of eggplant varieties and tomato varieties with S. torvum was studied. All S. torvum varieties showed resistance against bacterial wilt. All commercial eggplant and tomato varieties showed susceptibility to bacterial wilt. Two eggplant varieties (F-1 Kalenda and Naga Ungu) and two tomato scion varieties (Tomato SAnmarino and Tomato F-1 hybrid (Contra)) were grafted on S. torvum variety from these locations. The grafted combinations were compared with rootstock variety (S.torvum) and two susceptible scion varieties (Eggplant F-1 Kalenda and Tomato Sanmarino) by observing symptom under greenhouse condition and by counting the bacterial population in root, collar, stem (rootstock), and stem (scion) of inoculated plants in 10,20,and 30 days after inoculation. There was no disease incidence in all grafted combinations and S. torvum. In contrast, disease index was higher in two susceptible scion varieties. Although all grafted combinations and S. torvum showed no wilt symptom, the plants were latently infected with bacteria and the population were lower than two susceptible scion varieties in all plants parts. The colonization of bacteria in root and collar region after inoculation is common in resistant and susceptible cultivars and the degree of bacterial colonization in upper stem was important factor that determined the resistant and susceptibility of eggplant and tomato to bacterial wilt. Resistance of grafted plants to bacterial wilt was determined by rootstock.