Identification of Chromosomal Regions and Candidate Genes for IRound leaf/I Locus in ICucumis melo/I L

• Published in: Plants (Basel) 2024-04, Vol.13 (8)
• Main Authors: Fang, Xufeng, Zhu, Zicheng, Li, Junyan, Wang, Xuezheng, Wei, Chunhua, Zhang, Xian, Dai, Zuyun, Liu, Shi, Luan, Feishi
• Format: Article
• Language: English
• Subjects: Genetic aspects; Growth; Identification and classification; Leaves; Muskmelon; Plant chromosomes
• ISSN: 2223-7747; 2223-7747
• DOI: 10.3390/plants13081134

Leaf morphology plays a crucial role in plant classification and provides a significant model for studying plant diversity while directly impacting photosynthetic efficiency. In the case of melons, leaf shape not only influences production and classification but also represents a key genetic trait that requires further exploration. In this study, we utilized forward genetics to pinpoint a recessive locus, dubbed Cmrl (Round leaf), which is responsible for regulating melon leaf shape. Through bulked segregant analysis sequencing and extensive evaluation of a two-year F[sub.2] population, we successfully mapped the Cmrl locus to a 537.07 kb region on chromosome 8 of the melon genome. Subsequent genetic fine-mapping efforts, leveraging a larger F[sub.2] population encompassing 1322 plants and incorporating F[sub.2:3] phenotypic data, further refined the locus to an 80.27 kb interval housing five candidate genes. Promoter analysis and coding sequence cloning confirmed that one of these candidates, MELO3C019152.2 (Cmppr encoding a pentatricopeptide repeat-containing family protein, Cmppr), stands out as a strong candidate gene for the Cmrl locus. Notably, comparisons of Cmrl expressions across various stages of leaf development and different leaf regions suggest a pivotal role of Cmrl in the morphogenesis of melon leaves.