Abstract: We studied the morphological diversity of 250 foreign melon germplasm by examining 19 morphological characters. The foreign melon germplasm was rich in morphological diversity, with mean diversity index (Shannon’s index, H′) of 1.378. We found great variety in 9 qualitative characters (fruit shape, ground color of fruit skin, vein color of fruit skin, vein shape of fruit skin, density of net, thickness of net, flesh color, flesh texture, and seed coat color) and 4 quantitative characters (fresh weight of single fruit, thickness of fruit flesh, soluble solid content, and 1 000-seed weight), with H′ greater than 1.0 and 1.9, respectively. The degree of genetic diversity between various regions differed greatly. The upper-to-lower order of H′ for the various regions was south Asia (H′=1.512), northeast Europe (H′=1.404), west Europe (H′=1.372), north America (H′=1.340), and east Asia (H′=1.281). Cluster analysis divided the melon germplasm into four groups; south Asia, northeastern Europe, west Europe-North America, and east Asia-North America. The melon germplasm in south Asia (mainly represented by India) were rich in morphological diversity, which supports the Indian subcontinent as the original center of melon.

Key words: cluster analysis, foreign melon germplasm, genetic diversity, morphological character