QTLs and Candidate Gene Analyses for Fruit Size in Melon (Cucumis melo L.) under Domestication and Differentiation Based on High Resolution Maps

Melon is an important global horticultural crop with a high diversity. Fruit size is an important trait, not only for domestication and differentiation, but also for fruit quality. According to previously research, C. melo subsp. melo (melo) and C. melo subsp. agrestis (agrestis) have different domestication mechanisms and display great variance in fruit size. However, the QTLs related to fruit size in melon remain largely unknown, thus limiting utilization of germplasm and genome-guided crop improvement.In this study, we constructed two F2 populations that one generates from a cross between cultivated agrestis and wild agrestis, while another one from a cross between cultivated melo and cultivated agrestis. Those two populations can be used to map the candidate QTLs that play important roles in domestication and differentiation in melon. We revealed the different function enrichment of the genes located in segregation distortion regions in two F2 populations, and mapped two QTLs associate to fruit size. Our study provides a genomic resource that will facilitate to better understand the genetic basis of domestication and differentiation of fruit size in this important crop.