| Pepper is an important vegetable, however, affected by the hot and humid climate of the southern of China which Phytophthora capsici Leon.is a serious disease, once it break out will lead to a large area of pepper crops. So breed the resistance pepper varieties is urgent work, currently. But it’s time-consuming and workload of traditional breeding, and the use of molecular marker-assisted selection breeding purposes have to accelerate the process of breeding disease-resistant varieties.According to the different parts of pepper blight pathogen infection classify the disease into root rot, leaf rot, fruit rot and stem rot. Root rot disease in which the most serious, when break out will lead chili irreversible death. The results show that scholars genetic mechanisms of resistance from root rot diseases can be broadly divided into two types, quantitative resistance and specific resistance, and quantitative resistance controlled by multi-resistance gene, at present a number of research results detecting and locating the main effect of root rot disease resistance genes in chili on chromosome 5; specific resistance controlled by a single gene, the performance of some specific strains with full resistance, so far, root rot disease has not been specific resistance gene reported.Preliminary, this study used the material which is abroad internationally recognized anti-blight material chili CM334 (female) and high generation homozygous susceptible material 10399 (male), inheritance of resistance of root rot disease research shows that: infection by Guangdong Province Advantages physiological races Race3, the root rot disease resistance traits for a single dominant gene. In order to explore the position of pepper root rot disease resistance genes, we use SLAF-seq technology combined cluster segregation analysis (BSA) gene associated confrontational area for analysis and design and screening of SSR markers on the basis of the results were validated and Further fine mapping. The main conclusions are as follows:1. BC1F1 populations for materials, the construction of extreme phenotypic screening resistant and susceptible pools, combining separate cluster analysis (BSA) to mapping pepper root rot disease resistance genes.there are positioned at the ends of chromosomes No.10 to a related area, association area about the size of 16.4Mb, region detected SNP markers associated with 139, and comments to 680 genes.2. Download the associated region of the genome sequence, designed 131 pairs of SSR primers, and screened out 7 SSR markers simultaneously between resistant parental, susceptible parental and resistant and susceptible pool showed polymorphism, using seven polymorphic markers to identify the genotype of 636 BC1F1 population, combined genotypevand phenotype,survey data using MAPMAKER/EXP3.0 software analysis showed that more than seven polymorphic markers were associated with resistance gene linkage, and the resistance gene and further positioning mark SSR220-229-52 between SSR230-233-11, genetic distances were 2.7cM and 1.4cM.3. In the narrow range continue to design 66 pairs of SSR primers, and screened simultaneously in four SSR markers between resistant parental, susceptible parental and resistant and susceptible pool showed polymorphism, using four markers on recombinant strain genotypes exchange analysis, combined with phenotypic investigation, further resistance gene located between markers P52-11-21 and P52-11-41, genetic distances were 1.5cM and 1.1cM. |
PDF Full Text Request