Textural quality of watermelon fruit is mainly determined by rind hardness/firmness and its related traits. The determination of genetic regions harboring QTLs/gene(s) has a primary worth in genetic breeding studies. In this study, whole genome BSA-seq and QTL mapping through newly developed CAPS markers were successfully performed, respectively. Total 133-F₂ mapping individuals were derived from crossing of P₁ ‘1061’ and P₂ ‘812’ and slefing of F₁ offspring. Whole genome BSA-seq revealed major genetic region controlling rind hardness trait on chromosome 10. The genetic linkage map was assembled by genotyping of 133 pairs of codominant CAPS markers which spanned total 2606.38 cM length with averaged 19.60 cM distance among whole genome flanking markers. Moreover, CAPS markers based QTL analysis revealed total 5 putative QTLs [2 rind-hardness (RH), 1 rind toughness (RTO), 1 rind thickness (RTH) and 1 fruit weight (FW)] on three distinct chromosomes (2, 9, and 10), which mainly contributed 5.44–49.11% PVE. Interestingly, the combined molecular techniques expressed putative genetic region controlling rind hardness at chromosome 10. According to the BSA-seq result, major genetic region was detected between 1792001 and 4036000 bp on chromosome 10 with 2.24 Mb range, while from QTLs analysis, two co-localized focal QTLs “RH10 and RTO10” revealed 20 and 39 predicted genes at shortened genetic distances of 292.76 kbp and 405.31 kbp, respectively. A significant correlation and normal distribution frequencies for rind-phenotypes were also noticed. In crux, our combined techniques proved as an effective mapping strategies for identification of QTLs/gene(s) and provided a strong theoretical basis for future breeding studies in watermelon.

西瓜果实的质地质量主要取决于果皮的硬度/硬度及其相关性状。确定具有QTL /基因的遗传区域在遗传育种研究中具有重要价值。在这项研究中，分别通过新开发的CAPS标记成功进行了全基因组BSA-seq和QTL定位。总133-F ₂映射个体从P的交叉衍生₁ '1061'和P ₂ '812'和F的slefing ₁后代。全基因组BSA-seq揭示了10号染色体上主要的控制果皮硬度的遗传区域。遗传连锁图谱是通过对133对共显性CAPS标记进行基因分型而组装的，跨度共计2606.38 cM长度，平均全基因组侧翼标记之间的距离为19.60 cM。此外，基于CAPS标记的QTL分析揭示了三个不同的染色体上共有5个假定的QTL [2个果皮硬度（RH），1个果皮韧性（RTO），1个果皮厚度（RTH）和1个果重（FW）]（2，9和10），主要贡献了PVE的5.44–49.11％。有趣的是，组合分子技术在10号染色体上表达了控制果皮硬度的推测遗传区域。根据BSA-seq结果，在10号染色体上的主要遗传区域位于1792001和4036000 bp之间，范围为2.24 Mb，而根据QTL分析，“ RH10和RTO10 ”分别以292.76 kbp和405.31 kbp的较短的遗传距离揭示了20和39个预测基因。还注意到果皮表型的显着相关性和正态分布频率。在关键问题上，我们的结合技术被证明是鉴定QTL /基因的有效作图策略，并为将来的西瓜育种研究提供了坚实的理论基础。