QTL Analysis Of Cucumber Mosaic Virus Resistance In Pepper

Cucumber mosaic virus disease is one of the most serious diseases in pepper. The quality and yield of pepper are decreased seriously when infected by CMV. The most efficient and economical way of controlling the disease is the use of variental resistance. Therefore, it is one of the main targets to cultivate anti CMV resistant varieties. In this study, 5 different genotypes of pepper germplasms were used to explore Changes of CMV content in pepper plants after artificial inoculation with CMV by DAS-ELISA and RT-PCR. In addition, F2 populations(Carolina Wonder × 83-58) and RIL population(83-58 × Perennial) were used to analysis QTL loci by constructing a genetic linkage map,genetic analysis and QTL location. The main contents and results of this paper are as follows:(1)The variation of the levels of CMV in different materials after artificial inoculation 5~30 days: The virus content was increasing from 5 to 15 days, reached the peak at 15 day, and then fell back slightly, changed to be steady after 25 days. Low virus content suggested that these materials have strong resistance.(2)The F2 population included 276 individuals.KASPar genotyping technique which based SNP Marker was used for the study. Genetic linkage map was constructed by using Joinmap 4.0 software. The genetic map concluded 255 Kaspar markers, covering 1411.10 c M. The average interval distance between the markers was 5.53 c M.(3)The study was carried out using anti-CMV materials Perennial to construct two different genetic populations. These results by Genetic analysis showed that, The CMV resistance in F2 populations and RIL populations are both controlled by two partially additive-dominant major genes and additive-dominance polygenes and the polygenes effect existed at the same time. Our results showed that the CMV resistance in pepper is controlled by two dominant genes, and regulated by many minor genes at the same time. These results revealed that the CMV resistance belongs to quantitative inheritance.(4)F2 populations(Carolina Wonder × 83-58) and RIL populations(83-58 × Perennial) were used to QTL analysis for CMV resistance. One QTL loci CMV12 was detected on chromosome 12 in F2 populations, which accounted for 4.9% of the individual phenotypic variations. Three QTL loci CMV12.1、CMV12.2、CMV12.3 were detected on chromosome 12 in RIL populations, which accounted for 16.1%、11.2%、18.1% of the individual phenotypic variations respectively. CMV12 in F2 populations and CMV12.3 in RIL populations were located in near region on chromosome 12, which may contain many gene clusters for CMV resistance.