Inheritance of a Short-internode Mutant of `Mainstream' Muskmelon

A short-internode mutant of `Mainstream' muskmelon ( Cucumis melo L.), designated Main Dwarf, was crossed with 13 normal and six short-internode cultivars or breeding lines. Regardless of whether Main Dwarf was crossed with a normal or short-internode line, the F 1 family was normal for internode length. From crosses of Main Dwarf with normal lines, the F 2 families segregated in a 3 normal: 1 short-internode ratio and the families from backcrosses to Main Dwarf segregated 1 normal: 1 short internode. Crosses of Main Dwarf with short-internode lines produced F 2 families that segregated in a 9 normal: 7 short internode ratio and families from backcrosses to Main Dwarf that segregated 1 normal: 1 short internode. The segregation data from crosses of Main Dwarf with normal lines indicate that Main Dwarf has a recessive gene that conditions short internode. The segregation data from crosses of Main Dwarf with short-internode lines (five conditioned by si -1 and one conditioned by si -2) indicate that the recessive gene for short internode in Main Dwarf is not allelic to si -1 or si -2. The gene for short internodes in Main Dwarf is designated si -3.