Abstract:

The inheritance of seed characteristic was studied by using the populations derived from the Egusi watermelon PI186490 and the cultivated watermelon LSW-177. A F₂ genetic linkage map which included 195 CAPS markers was constructed. The map contained 11 linkage groups which corresponded with the chromosome and spanned 2 029.8 cM with a mean marker interval of 10.46 cM. Twenty-three QTLs for the seed traits were detected on LG1，LG2，LG3，LG5，LG6，LG8，LG11 and explained 2.2014%–28.8950% of the phenotypic variation. Of all the QTLs，4 QTLs for seed length，seed width，seed thickness and 100-seed weight explained over 17% of the phenotypic variation. Ten QTLs were identified on LG6，which contain 3 QTLs for seed length，4 QTLs for seed width，1 QTL for seed thickness and 2 QTLs for 100-seed weight. Four QTLs which explained over 17% of the phenotypic variation were also located on LG6 and QTL for seed width and 100-seed weight were both located on the two CAPS markers WⅢ6-503 and WⅢ6-502.

Key words: watermelon, seed, trait, CAPS, genetic linkage map, QTL