Linkage mapping in watermelon population segregation for subgynoecious trait
LIU Li1,JIAO Ding-liang2,GUO Min1,ZHANG Qin-ying1,HU Bao-gang1,SHANG Ji-peng2,ZHANG Yan-ning2 (1College of Agriculture and Bioengineering,Tianjin University,Tianjin 300072 China; 2Tianjin Kernel Vegetable Research Institute,Tianjin 30038 China)
RAPD,AFLP and SSR markers were used to generate a linkage map in an F2 population derived from a cross between the subgunoecious line BG1 (female flower proportion above 80%)and normal sexual line 900134 (Afriacan wild germplasm,female flower proportion about 10% to 20%). A linkage map covering 1 073.1 cM with a mean marker interval of 7.2 cM was constructed. 4 RAPD,140 AFLP,6 SSR markers and a subgy (subgynoecious trait)spanned 17 linkage groups. The location of subgy was defined in the linkage group 5 by genetic linkage and analysis to be associated with RAPD locus s1454-1100 and AFLP locus GT-CTA270 at 5.8 cM and 14.3 cM,respectively. The band s1454-1100 was collected and sequcenced to synthesis a sequence-characterized amplified region (SCAR)primer,which was used to amplify the individual DNA of the F2 population and obtained a special band of 375 bp in the most of homozygous subgynoecioius individuals and heterozygous normal sexual individuals. The genetic distance between this band and subgy was 6.1 cM by linkage analysis using the software Jionmap 3.0. The result indicated that a successful conversion of the SCAR marker from RAPD. This SCAR marker was designed as SR375. It will contribute to the further study and breeding for subgynoecioius in watermelon.