Identification of fruit quality and morphology QTLs in melon (Cucumis melo) using a population derived from flexuosus and cantalupensis botanical groups

Abstract

Fruit traits, such as shape, size, sugar concentration, and β-carotene concentration affect fruit quality in melon. Extensive genetic diversity for these traits can be exploited for breeding purposes. In this study, an F2 mapping population was constructed using an orange fleshed cantaloupe-type melon and an exotic green fleshed “snake melon” to identify quantitative trait loci (QTL) associated with fruit quality and fruit morphological traits. A total of 31 QTLs were identified, of which 23 corroborated previously reported QTLs. A small segment of LG8 explained most of the phenotypic variation for yield. We mapped eight new QTLs for fruit shape, total fruit weight per plant, soluble solids concentration, flesh color, ovary shape and seed cell diameter, and a locus for chlorosis in this study. Soluble solids concentration did not have significant association with average fruit weight and fruit width, suggesting that manipulation of fruit morphology is possible in melon without considerably affecting fruit sweetness. A significant positive association between fruit shape and ovary shape indicated that fruit shape was determined during preanthesis. Our results indicate that natural variation for internal and external melon fruit traits can be further explored by performing QTL analysis of populations derived from crosses between previously unexplored botanical groups.