Development of Diagnostic Molecular Markers for Marker-assisted Breeding against Bacterial Wilt in Tomato

다국어 초록 (Multilingual Abstract)

Bacterial wilt, caused by the Ralstonia pseudosolnacearum species complex (RSSC), is an economically significant vascular disease that limits tomato production in tropical and subtropical regions. Two major quantitative trait loci (QTL) of bacterial wilt resistance on chromosome 6 (Bwr-6) and 12 (Bwr-12) were previously identified in Solanum lycopersicum ‘Hawaii 7996’; however, marker-assisted breeding for bacterial wilt resistance is not well established. To dissect the QTL, seven markers were developed based on the SNPs near the two QTLs from whole genome resequencing data. Six cleaved amplified polymorphic sites (CAPS) and derived CAPS(dCAPS) markers within the Bwr-6 region and dCAPS marker near Bwr-12 were developed, and resistance levels in 117 tomato cultivars were evaluated. Two markers, RsR6-5 on chromosome 6 and RsR12-1 on chromosome 12, were selected based on the genotypic and phenotypic analysis. The combination of Ch6-5 and Ch12-1 effectively distinguish resistant and susceptible cultivars. Furthermore, the efficiency of the two markers was validated in the F₃ generation derived from the F₂ population between E6203(susceptible) and Hawaii 7996 (resistant). Resistant alleles at both loci led to the resistance to bacterial wilt. These markers will facilitate marker-assisted breeding of tomato resistant to bacterial wilt.