Investigation of Virus Resistance Spectrum and Fine Mapping of the Potyvirus Resistance Gene Pvr7 in Capsicum annuum

Abstract

Pepper mottle virus (PepMoV) is a frequently occurring virus in pepper field. PepMoV infected plants show symptoms including mosaic leaf, distortion of foliage and fruit deformation. Previous research revealed that Pvr7 is located on chromosome 10 and linked to the dominant potyvirus resistance gene Pvr4 and Tomato spotted wilt virus (TSWV) resistance gene Tsw. Virus resistance test showed that Capsicum annuum 9093 harboring Pvr7 was resistant to PepMoV but susceptible to TSWV, Tobacco etch virus (TEV), and Chilli veinal mottle virus (ChiVMV) To develop a high resolution map of the Pvr7 locus, an intraspecific F2 mapping population was constructed by crossing C. annuum 9093 (PepMoV resistant) and C. annuum Jeju (PepMoV susceptible). A total of 916 of F2 plants were screened with green fluorescent protein (GFP) tagged PepMoV. For genotyping, a forty-four of randomly distributed single nucleotide polymorphism (SNP) markers located in chromosome 10 were tested to conform polymorphism among 9093, Jeju and 9093 x Jeju F1. In sequence, 4 SNP markers were selected and tested to F2 mapping population. To define target region of Pvr7, C. annuum CM334 whole genome sequence (WGS) was used to develop SNP markers. Consequently, a four of SNP markers were developed additionally. Comparing phenotype and genotype data, eight recombinants were selected. A three of SNP markers were co-segregated with Pvr7 exactly. These results indicated that the target region of Pvr7 gene is located within 258kb. Using CM334 reference sequence, a nine of NBARC type genes were predicted in this region. We are expecting that 0 cM of Pvr7 SNP markers can be used to breeding PepMoV resistant cultivars and fine mapping of Pvr7.