A spontaneous dwarf mutant was discovered from inbred watermelon line ‘5-6y’. Genetic study showed that the dwarf mutant is genetically stable and the dwarf trait is inherited as a single recessive gene. Allelism test showed that the new dwarf gene is not allelic to the two known dwarf genes dw-1 and dw 2. The allelism test of this new mutant with dw-3 was not possible because the genetic stock of dw-3 is no longer available. The phenotype of this mutant appears different from dw-3 and we suggest that the new mutant gene is named as dw-4.
Key word: Watermelon; Dwarf, Gene