Estimation of phenotypic divergence in a collection of Cucumis melo, including shelf-life of fruit

Genetic diversity in 44 melon accessions collected from Southern India was assessed by examining variation in 36 phenotypic characters with emphasis on shelf-life, and the relationships between shelf-life and related characters were investigated. Principal component analysis (PCA) revealed that fruit shape, fruits per plant, flesh firmness, quality of flesh, flesh juiciness, seeds per fruit, shelf-life, rind hardness, flesh thickness, fruit diameter and fruit weight were the principal characters to discriminate melon accessions examined in the present study. These accessions had two important varieties, Cucumis melo var. momordica and Cucumis melo var. acidulus. PCA was performed to determine relationships among populations and to obtain information on the usefulness of those characters for the definition of groups. According to the scatter diagram, acidulus and momordica formed different clusters. Shelf-life of acidulus fruit was significantly correlated with the following characters: quality of flesh, flesh firmness, fruit shape, flesh thickness, flesh colour and rind hardness. The fruits of momordica had faint odour, mealy and orange pulp, with short shelf life. The fruits of acidulus had no odour, crispy and off white pulp, with a long shelf life (more than 6 months). This evaluation of fruit trait variability can assist geneticists and breeders to identify populations with desirable characteristics for inclusion in variety breeding programmes.