Melon (Cucumis melo L.)

The melon species is a member of the broader Cucurbitaceae family, which encompasses over 100 genera and more than 800 species. The family includes some of the most important agricultural and horticultural crops, such as melon (Cucumis melo), cucumber (Cucumis sativus), watermelon (Citrullus lanatus), pumpkins and squashes (Cucurbita species). The fleshy fruit of most cucurbits are berries characterized as "pepos" and there is extreme diversity for fruit characteristics such as size, shape, color and quality traits in the cucurbits as a family, and the melon species exemplifies this broad variation.

Varieties of melon are grown throughout the world and generally consumed as sweet desert fruits when mature. However, there are also varieties of melon that are consumed as young immature fruit, much like cucumbers, and served either fresh or pickled. Melon cultivation encompasses nearly a million hectares worldwide, producing over 15 million tons of fresh fruit annually.

Melons harvested for META-PHOR in Israel: Tam Dew (TD) (left) and Noy Yizre'el (NY) (right)

Although sweet melon varieties are all characterized by high sugar concentrations, the variation in flavor profiles is very large for a single species. Both genetic and environmental factors impact on the fruit biochemistry and subsequently on the fruit metabolite levels. The interaction between genetic and environmental factors determine the variation for the multitude of chemical quality components such as pigments, organic acids, and especially the volatile and non-volatile metabolite components that bestow upon each cultivar its characteristic flavor.

Mellons are harvested at commercial maturity, samples are cut and deep-frozen in iquid nitrogen. Pieces are grinded to powder and stored at -80°C. Frozen ground samples are shipped to the different META-PHOR partners for metabolome analysis using different techniques (LCMS, GCMS, NMR).