Sources of resistance to bacterial wilt in Capsicum

Abstract

Seventy-four sweet pepper accessions (Capsicum annuum L.), 59 hot pepper accessions (C. annuum), and 63 other Capsicum spp. accessions were screened for resistance to bacterial wilt (Ralstonia solanacearum (Smith 1896): Synonym Pseudomonas solanacearum E. F. Smith) to find the resistant materials. After 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 disease index ranging from 0= symptomless to 4= death. Resistance of highly resistant 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 other Capsicum spp., particularly in sweet pepper, and their commercial F1 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 all 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 other areas such as North and South America, Europe, etc. did not possess this characteristic.