Study of genetic variation and morphological traits in 25 melon cultivars by using molecular marker techniques (original) (raw)

Genetic variation and 12 morphological traits of 25 melon cultivars, comprising 22 muskmelon/cantaloupe and three Thai melon accessions, were studied. The Thai melons were TM-RFS, TM-LFS and TM-OFS, which have round, long and oblongata fruit shape, respectively. The melon cultivars did not shown significant differences in stem diameter, but the other 11 morphological traits were found to be significantly different. ML1496, TM-RFS and TM-LFS had the highest leaf stem angle. The pulp percentage and fruit firmness were highest in ML1496; 'Sweety' had the highest fruit weight; 'Green Jam' showed the largest fruit perimeter and fruit width; TM-LFS and TM-OFS had the greatest fruit length and cavity width; 'Golden Sun' gave the highest fruit flesh thickness; ML052 showed the highest peel thickness; and NUN2002 and 'Honey Sweet' had the highest total soluble solids. Cluster analysis using morphological traits classified the melon cultivars into nine groups (at R 2 =0.75), with five cultivars in groups 8 and 9, four in group 6, three in group 1, two each in groups 2, 3 and 7, and only a single cultivar in each of groups 4 and 5. Three primers [ISSR_(GA)8YG, ISSR_(ATG)6 and RAPD_OPL07] from 13 primer sets grouped the melon cultivars in only two cluster groups (Thai melon group and muskmelon group). When using morphological traits combined with molecular markers, the analysis classified the melons into seven groups at R 2 =0.83: four cultivars in group 6, three in group 5, two each in groups 1 and 4, and a single cultivar each in groups 2 and 3. These results will help support the efficiency of parent line selection in the muskmelon/cantaloupe and Thai melon breeding programs.