Genetic mapping of loci determining seed coat color and size in watermelon

Seed size and color are important traits of watermelon influencing consumer appeal and market acceptance. However, only few attempts have been made to dissect the genomic region or gene(s) determining these traits. The molecular regulatory mechanisms underlying these traits in watermelon are complex and still unclear. In the current experiment, we have made an attempt to map the QTLs for these seed traits in BC1F2 mapping population of cross BIL-53 (Citrullus amarus) x IIHR-140-152 (Citrullus lanatus). Analysis revealed two QTLs viz., q_100SW_2.1 and q_100SW_6.1 for 100seed weight; three QTLs viz., q_SCC_3.1, q_SCC_5.1 and q_SCC_5.2 for seed coat color. GO annotation of genes located in these QTL regions predicted putative candidate genes for seed size and color. The PCR based flanking markers identified in the current study for seed weight, BVWS02340 and BVWI00252 on chromosome 2, BVWS02424 and BVWS00117 on chromosome 6; for seed coat color, BVWS01383 on chromosome 3, BVWS01643 and BVWI00228, BWWS00854 and BVWS02096 on chromosome 5 can be used for marker assisted selection (MAS) of watermelon seed traits.