Induction of parthenogenetic haploid embryos after pollination by irradiated pollen in watermelon

Parthenogenetic haploid embryos of `Crimson Sweet', `Halep Karasi', `Sugar Baby' and `Panonia F1' watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] were obtained after pollination with γ-irradiated (200 or 300 Gy) pollen. Some globular and heart-shaped embryos were observed in fruit harvested 2 to 5 weeks after pollination. The number of embryos per 100 seeds was highest for `Halep Karasi'. After in vitro culture, 17 haploid plants were obtained and doubled haploid lines were generated after chromosome doubling using colchicine.