Inheritance of Suppressed-Branching in Melon and Its Association with Some Other Morphological Characters

The suppressed branching trait in melon is a labor saving characteristic because it eliminates the need to prune lateral shoots. The mode of inheritance of this suppressed branching trait, derived from Cucumis melo var. agrestis and introduced into 'Melon Ano No.17', was investigated. Segregation of branching types in F1, its reciprocal cross F2 and backcross progenies from the cross between 'Melon Ano No.17' and 'Harukei-3', a normal branching variety, fits the expected ratio assuming that the trait is controlled by a single recessive nuclear gene. Contrarily, F1 progenies between 'Melon Ano No.17' and 'YS-Honeydew', another normal branching variety, exhibited a continuous variation from the suppressed branching type to the normal branching type. These results suggest that the suppressed branching trait is controlled by a single recessive or incompletely dominant major gene, which we call suppressed branch (symbolized by sb), and that the degree of dominance may greatly be affected by the genetic background and/or environmental factors. When the relationship between suppressed branching trait and some other characters in the F2 progenies of 'Melon Ano No.17' and 'Harukei-3' were examined, the suppressed branching trait correlated negatively with plant vigor.