Linkage mapping in watermelon population segregation for subgynoe-cious trait

LIU Li; JIAO Ding-lian; GUO Min; ZHANG Qin-ying; HU Bao-gang; SHANG Ji-peng; ZHANG Yan-ning

Abstract：RAPD,AFLP and SSR markers were used to generate a linkage map in an F_2 population derived from a cross be-tween 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-CTA_(270) at 5.8 cM and 14.3 cM,respectively. The baud 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 F_2 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 soft-ware Jionmap 3.0. The result indicated that a successful conversion of the SCAR marker from RAPD. This SCAR marker was designed as SR_(375). It will contribute to the further study and breeding for subgynoecioius in watermelon.