Climacteric and non-climacteric behavior in melon germplasm, a model to study fruit ripening

Melon (Cucumis melo L. Cucurbitaceae) represents one of the most variable species within the genus Cucumis as well as among the other cultivated plants. Moreover it is a key species in order to study ethylene involvement in ripening because several climacteric and non-climacteric accessions are available. A core collection of 176 melon accessions including wild relatives, feral types, landraces, breeding lines and commercial cultivars from 54 countries was seleced for this study. This collection was genotyped with AFLP and SNP markers and extensively phenotyped for plant and fruit traits at COMAV, including the abscission layer formation as indicator of climacteric/non climacteric ripening. PCA based on SNP markers confirmed the division of this species in clear subspecies; melo and agrestis. Among ssp agrestis genotypes, African wild types were easily distinguished from far eastern conomon along PC1, while PC2 separated Indian momordica from the rest. Melo subspecies comprises five groups distributed along PC1 and PC2. A high degree of variability for abscission layer formation (from full-slip to abscense) was s been observed among and within groups indicating that the genetic variability present in this species is appropriated to study climacteric and non-climacteric ripening. Acknowledgement: C.L. is recipient of a Marie Curie Career Integration Grant (CIG) and her visit to IBMCP-COMAV (Valencia) is supported by a Cost Action FA1106 Quality Fruit - Short-Term Scientific Mission (STSM)