Development of SNP based Markers Associated with Bacterial Wilt Resistance in Pepper (Capsicum annuum)

Bacterial wilt (BW) caused by Ralstonia solanacearum is one of the most prevalent vascular disease of diverse plant species from dicots to monocots. Because of its complex genetics mediating BW resistance, the genomic factors have been poorly understood. Based on previous studies, we selected 28 candidate genes related to BW resistance and identified significant differences in the expression levels of five genes between two pepper cultivars, YCM334 (BW resistant) and Taean (BW susceptible). Cleaved amplified polymorphic sequences (CAPS) markers were developed on two genes, CA03g23820 and CA04g02500 and BW susceptible/moderate resistant/resistant genotypes can be successfully determined. CA03g23820 is annotated as beta-galactosidase that may play an important role in pathogen invasion through vascular tissue and CA04g02500 is annotated as detected protein of unknown function. The CAPS markers for CA04g2500 showed significant association with BW resistance among a recombinant inbred line population (YCM334 x Taean). Although different markers can be developed depending on genotypes, the results in this study will help account for BW resistance in pepper, and facilitate breeding process using marker-assisted selection.