Developmental Changes of Recessive Genes-mediated Cucumber mosaic virus (CMV) Resistance in Peppers (Capsicum annuum L.)

Cucumber mosaic virus (CMV) is one of the most important viral diseases in pepper (Capsicum annuum L.), and severalgenes for resistance were reported in Capsicum spp. In Korea, a single dominant gene that is resistant to CMV Fny and CMV P0has been used for breeding. Recently, a new strain (CMV P1) was reported that could infect cultivars resistant to both CMV Fnyand CMV P0. Therefore, breeding of more robust CMV-resistant cultivars is required. In this study, we surveyed the inheritanceof CMV P1 resistance and analyzed the location of the resistance loci. After CMV P1 inoculation of various germplasms and breedinglines, one accession (ICPN18-8) showed no visual symptoms at 15 dpi (days post inoculation) but was susceptible after 45 dpi,and one resistant line (I7339) showed resistance until at 45 dpi. The latter line was used for tests of resistance inheritance. A total of 189 F2 plants were examined, with 42 individuals showing resistance at 15 dpi and a phenotype segregation ratioclose to 1:3 (resistant:susceptible plants). In a lateral ELISA test at 45 dpi, 11 plants showed resistance, and the segregationratio was changed to 1:15. These results indicate that resistance in C. annuum ‘I7339’ is controlled by two different recessivegenes; we named these resistance genes ‘cmr3E’ and ‘cmr3L,’ respectively. To locate these two resistant loci in the pepper linkagemap, various RAPD, SSR, and STS markers were screened; only nine markers were grouped into one linkage group (LG). Onlyone RAPD primer (OPAT16) was distantly linked with cmr3E (22.3 cM) and cmr3L (20.7 cM). To develop more accurate markersfor marker-assisted breeding, enriching for molecular markers spanning two loci will be required. KCI Citation Count: 2