Key Laboratory of Biology and Genetic Improvement of Horticulture Crops (Northeast Region), Ministry of Agriculture and Rural Affairs, College of Horticulture and Landscape Architecture, Northeast Agricultural University, Harbin 150030, China.
College of Horticulture and Landscape Architecture, Northeast Agricultural University, Harbin 150030, China.
J Agric Food Chem. 2023 Oct 25;71(42):15445-15455. doi: 10.1021/acs.jafc.3c02122. Epub 2023 Oct 10.
Flesh color is a significant characteristic of watermelon. Although various flesh-color genes have been identified, the inheritance and molecular basis of the orange flesh trait remain relatively unexplored. In the present study, the genetic analysis of six generations derived from W1-1 (red flesh) and W1-61 (orange flesh) revealed that the orange flesh color trait was regulated by a single recessive gene, (orange flesh). Bulk segregant analysis (BSA) locked the range to ∼4.66 Mb, and initial mapping situated the locus within a 688.35-kb region of watermelon chromosome 10. Another 1,026 F plants narrowed the locus to a 304.62-kb region containing 32 candidate genes. Subsequently, genome sequence variations in this 304.62-kb region were extracted for BSA strategy among 11 resequenced lines (one orange flesh and ten nonorange flesh) and finally narrowed the locus into an 82.51-kb region containing nine candidate genes. Sequence variation analysis of coding regions and gene expression levels supports as the most possible candidate for , which encodes carotenoid isomerase (). This study provides a genetic resource for investigating the orange flesh color of watermelon, with malfunction resulting in low lycopene accumulation and, thus, orange flesh.
果肉颜色是西瓜的一个重要特征。尽管已经鉴定出了各种果肉颜色基因，但橙色果肉性状的遗传和分子基础仍相对未知。在本研究中，来自 W1-1（红色果肉）和 W1-61（橙色果肉）的六代遗传分析表明，橙色果肉颜色性状由一个隐性单基因调控，命名为 （orange flesh）。BSA 分析将基因定位在大约 4.66Mb 的范围内，初步定位将 基因定位于西瓜 10 号染色体的 688.35kb 区域内。另外 1026 个 F2 植株将 基因定位在一个包含 32 个候选基因的 304.62kb 区域内。随后，在 11 个重测序系（一个橙色果肉和十个非橙色果肉）中，通过 BSA 策略提取了这个 304.62kb 区域中的基因组序列变异，并最终将 基因定位在一个包含九个候选基因的 82.51kb 区域内。编码区序列变异分析和基因表达水平支持 作为 的最可能候选基因，该基因编码类胡萝卜素异构酶（）。本研究为研究西瓜的橙色果肉颜色提供了遗传资源， 基因的功能失常导致番茄红素积累减少，从而形成橙色果肉。
