Genetic analysis and identification of molecular markers associated with lobed leaf shape in watermelons using next generation sequencing

• Published in: Horticulture, environment and biotechnology Vol. 65; no. 5; pp. 867 - 876
• Main Authors: Jang, Yoon Jeong, Cho, Huijoo, Oh, Eungyeol, Kook, Cheolho, Kim, Yongjae, Lee, Gung Pyo
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01.10.2024; Springer Nature B.V; 한국원예학회
• Subjects: absorption; Agriculture; Biomarkers; Biomedical and Life Sciences; Chemical synthesis; Citrullus lanatus; dominant genes; energy; Energy absorption; Essential nutrients; Fruits; Gas exchange; Gene expression; Gene mapping; Gene sequencing; Genetic analysis; Genetic crosses; genetic improvement; Genomic analysis; genomics; Korean Peninsula; leaf morphology; Leaves; Life Sciences; Next-generation sequencing; Nucleotides; Nutrients; Photosynthesis; Plant Breeding/Biotechnology; Plant Ecology; Plant Physiology; Polymorphism; progeny; Research Report; Single-nucleotide polymorphism; Water melons; watermelons; 농학; Korean Peninsula; Bulked segregant analysis-next-generation sequencing; Single nucleotide polymorphism; Leaf shape; Watermelon; High-resolution melt
• ISSN: 2211-3452; 2211-3460
• DOI: 10.1007/s13580-024-00617-3

Leaves are vital organs for photosynthesis, gas exchange, and light energy absorption in plants and play a crucial role in synthesizing essential nutrients. Watermelon is a widely cultivated crop worldwide and has a range of leaf shapes, including non-lobed (entire), semi-lobed, and highly lobed varieties. However, few studies have focused on lobed leaf traits in watermelons. Therefore, our study aimed to elucidate the genetic basis of leaf lobing regulation in watermelons, focusing on lines cultivated in Korea. We analyzed the F2 progeny derived from crosses between the highly lobed SIT463ST and the non-lobed PS137 watermelon line. We discovered that lobed leaf traits in watermelons are controlled by a single incomplete dominant gene. Additionally, we used next-generation sequencing-based bulked segregant analysis sequencing to identify a candidate genomic region spanning 24.06–24.09 Mb (25 kb) on Chr. 4. Three single nucleotide polymorphism markers (LL-4-238, LL-4-956, and LL-4-252) were developed that were closely associated with the non-lobed leaf margin shape in the F2 population. Analysis of the expression levels of these genes in the fine mapping region revealed only synonymous substitutions in the coding regions, suggesting that mutations in potential promoter regions may regulate gene expression, thereby affecting leaf morphology. These findings provide valuable insights into the molecular factors underlying non-lobed leaf traits in watermelons and offer potential targets for genetic improvement.