Construction Of A High-density Genetic MAP And QTL Analysis Of Several Traits In Pepper (Capsicum Annuum)

Pepper is cultivated widely around the world,with high economic value and good environment adaptability.With the development of biotechnology,using molecular markers to construct a genetic map and QTL analysis on some important traits have been a effective method of molecular breeding of pepper.In this study,a genetic map was constructed based on SNP,InDel and SSR markers and F2 population derived from the cross between Capsicu,m annuum ’G16’ and ’DFSJ’ to identify the QTL of several traits in pepper.The main results are as follows:1.A high density map of pepper was constructed by using parent material,DFSJ’ x’G16’(named DG).There were 13,084 SNP markers,27 SSR markers and 90 InDel markers in DG map which containing 1,675 bins.The total map distance was 1,547.97cM and the average distance between markers was 0.24cM.A total of 12 linkage groups corresponded to 12 chromosomes one by one and the linkage group length was between 92.7～183.75cM.The physical map length was 2,603.91Mb,covering about 80.12%of the whole genome length(3.25 G)of ’Zunla-1’.2.The QTL of several traits in two population(including 94 strains of Guangzhou population and 59 strains of Haikou population)were analyzed by MapQTL6 software.A total of 10 QTLs were detected from nine traits in Guangzhou population,the traits including flower color,style color,first flower node,fruit orientation,fruit color,fruit weight,fruit length,fruit diameterand peel thickness,which were located on four linkage groups respectively and explained 7.73%to38.53%of phenotypic variation.A total of 10 QTLs were detected from seven traits in Haikou population,the traits includingflower color,fruit orientation,fruit color,fruit weight,fruit length,fruit diameter,andpericarp thickness,which were located on six linkage groups respectively and explained 4.37%to 64.66%of phenotypic variation.The results showed that the the sixQTLs of the two populations were both mapped.The QTLs on the same chromosomes were detected in the fruit color,fruit position,fruit length,pericarp thickness and fruit diameter.3.Based on the information of reference genome of pepper,the candidate genes of fourQTL,gzhs10.1 gzhz10.1,gzcxl2.1 and hkgs10.1 were predicted,and 45,21,110 and 49 candidate genes were predicted respectively.In hkgs10.1 interval,we found a gene(Capanal0g001609)may participate in controling the fruit color.Capana10g001609 is homologous to CIPK14,which is a stress responsive GBL-interacting protein kinase gene,involved in phytochrome A-mediated far-red light inhibition of greening in Arabidopsis seedlings.