Fruit Morphology and Clustering Analysis Reveals Diversity among Commercial Melons(Cucumis melo L.) in Indonesia

Melon (Cucumis melo L.) is a globally important horticultural crop known for its remarkable morphological and agronomic diversity.However, commercial varieties in Indonesia remain poorly characterized.Here, we evaluated 24 C. melo varieties using 14 quantitative and 4 qualitative fruit traits related to size, shape, rind, flesh, seed morphology, and sugar content.Analysis of variance revealed significant differences among varieties (p<0.05) for all traits.Principal component analysis (PC1 = 50.8%,PC2 = 36.7%)and hierarchical clustering identified three major phenotypic groups.Random forest modeling ranked trait importance based on %IncMSE, identifying seed cavity length, seed cavity index, and fruit diameter index as top predictors (importance score >10%).Integration of PCA, heatmap clustering, and variable importance plots confirmed these three traits as robust diagnostic markers.These findings highlight key morphological features for varietal classification and breeding, and provide a phenotypic framework for future genetic studies of melon in Indonesia.