Horticulture College, China Agricultural University, Beijing 100193, China.
Institute of Horticultural Research, Ningxia Academy of Agriculture and Forestry Sciences, Yinchuan 750002, China.
Genes (Basel). 2024 Jul 17;15(7):933. doi: 10.3390/genes15070933.
The watermelon ( L.) holds substantial economic value as a globally cultivated horticultural crop. However, the genetic architecture of watermelon fruit weight (FW) remains poorly understood. In this study, we used sh14-11 with small fruit and N14 with big fruit to construct 100 recombinant inbred lines (RILs). Based on whole-genome resequencing (WGR), 218,127 single nucleotide polymorphisms (SNPs) were detected to construct a high-quality genetic map. After quantitative trait loci (QTL) mapping, a candidate interval of 31-38 Mb on chromosome 2 was identified for FW. Simultaneously, the bulked segregant analysis (BSA) in the F2 population corroborated the identification of the same interval, encompassing the homologous gene linked to the known FW-related gene . Additionally, RNA-seq was carried out across 11 tissues from sh14-11 and N14, revealing expression profiles that identified 1695 new genes and corrected the annotation of 2941 genes. Subsequent differential expression analysis unveiled 8969 differentially expressed genes (DEGs), with 354 of these genes exhibiting significant differences across four key developmental stages. The integration of QTL mapping and differential expression analysis facilitated the identification of 14 FW-related genes, including annotated TGA and NAC transcription factors implicated in fruit development. This combined approach offers valuable insights into the genetic basis of FW, providing crucial resources for enhancing watermelon cultivation.
西瓜（L.）作为一种全球广泛种植的园艺作物，具有巨大的经济价值。然而，西瓜果实重量（FW）的遗传结构仍知之甚少。在本研究中，我们利用小果型 sh14-11 和大果型 N14 构建了 100 个重组自交系（RILs）。基于全基因组重测序（WGR），检测到 218,127 个单核苷酸多态性（SNPs），构建了一个高质量的遗传图谱。在进行数量性状位点（QTL）作图后，在第 2 号染色体上确定了一个 31-38 Mb 的候选区间，与 FW 相关。同时，F2 群体的混池分离分析（BSA）也证实了同一区间的存在，该区间包含与已知 FW 相关基因 同源的基因。此外，对 sh14-11 和 N14 的 11 种组织进行了 RNA-seq 分析，揭示了表达谱，鉴定了 1695 个新基因，并纠正了 2941 个基因的注释。随后的差异表达分析揭示了 8969 个差异表达基因（DEGs），其中 354 个基因在四个关键发育阶段表现出显著差异。QTL 作图和差异表达分析的整合有助于鉴定 14 个与 FW 相关的基因，包括参与果实发育的注释 TGA 和 NAC 转录因子。这种综合方法为 FW 的遗传基础提供了有价值的见解，为提高西瓜种植提供了重要资源。
