ESTABLISHMENT OF A VEGETABLE MELON GERMPLASM COLLECTION FROM SALENTO (SOUTHERN ITALY) INFORMED WITH WHOLE-GENOME SEQUENCE AND PHENOTYPIC DATA

The species Cucumis melo L. includes two vegetable melons, the cucumber melon (C. melo var. chate) and the snake melon (C. melo var. flexuosus), once widespread across the Mediterranean Basin but now confined to small cultivation areas. The cucumber melon, popular in Antiquity and the Middle Ages, is now largely confined to Apulia region (Southern Italy), especially the Salento area. Recently, its consumption has increased both inside and outside the regional boundaries. Here, we describe the collection and characterization of 13 cucumber melon and two snake melon populations from Salento, locally known as meloncella, spuredda and cucummaru. Whole-genome resequencing of DNA pools was conducted to investigate genetic diversity. The cucumber melon population UBGCMC111, widely traded and distinguished by deep grooves on the pepo, exhibited the lowest heterozygosity, likely due to strong farmer selection. Genetic analyses revealed the divergence of UBGCMC111 and UBGCMC053 originating from an area in Salento with historical linguistic and cultural ties to Greek heritage. The two snake melon populations did not form a distinct lineage, suggesting genetic similarity between the chate and flexuosus botanical varieties. In total, 1,307 private and fixed alleles were identified, including 162 in the UBGCMC111 population valuable for its traceability. Replicated field trials enabled the selection of superior populations based on agronomic and commercial traits, including fruit number per plant, yield, and earliness. Overall, this study safeguards valuable C. melo genetic diversity and provides genomic and phenotypic data for integrating unexplored genetic resources into mainstream agrifood systems and breeding programs.