Sources of resistance to bacterial wilt in Capsicum

Seventy-four sweet pepper accessions (Capsicum annuum L.), 59 hot pepper ac cessions (C. annuum), and 63 other Capsicum spp. accessions were screened f or resistance to bacterial wilt (Ralstonia solanacearum (Smith 1896): Synon ym Pseudomonas solanacearum E. F. Smith) to find the resistant materials. A fter the plants were transplanted to a field infested with R. solanacearum at NIVOT, then an inoculum suspension of R. solanacearum was poured around them. For evaluation of resistance, each accession was scored by using a di sease index ranging from 0= symptomless to 4= death. Resistance of highly r esistant accessions whose disease index was less than 1 was evaluated again by a seedling test. Highly resistant accessions were found in sweet peppers, hot peppers, and o ther Capsicum spp., particularly in sweet pepper, and their commercial F-1 cultivars. Therefore, bacterial wilt infection can be controlled by the use of the resistant cultivars identified in this study. 'Mie-Midori' and its progenies were used as parents for the breeding nearby ail resistant Japanese green pepper cultivars identified in this study. In sweet and hot pepper which originated in Asia i.e., Japan, China, etc., exhibit high or moderate resistance to bacterial wilt, whereas those from o ther areas such as North and South America, Europe, etc. did not possess th is characteristic.