Sources of resistance to bacterial wilt found in Vietnam collections of pepper (Capsicum annuum) and their nuclear fertility restorer genotypes for cytoplasmic male sterility

Abstract

Eleven hot pepper accessions collected in Vietnam showed stable resistance to bacterial wilt as well-known resistance sources, MC4 and MC5, in repeated inoculation tests with different Ralstonia solanacearum isolates conducted from 2004 to 2010. Seven of these accessions (specifically KC981, KC1006, KC1021, KC1027, KC1045, KC1050, and KC1055) resulted in stable male sterile F1 plants in the crosses with a cytoplasmically male sterile (CMS) Chilseong (CMS-A, Srfrf), and therefore, they were maintainers (CMS-B) with a genotype of Nrfrf. The rest (KC980, KC995, KC999, and KC1009) produced stable male fertile F1 plants in the crosses, and therefore, were restorers (CMS-C) with a genotype of N(S)RfRf. Therefore, the maintainer and restorer sources of resistance may be used in preference in breeding maternal (CMS and their maintainers) and paternal parents (restorers) for resistance to bacterial wilt, respectively, in the hybrid breeding system utilizing cytoplasmic male sterility. © The Korean Society of Plant Pathology.