Obtention of haploid embryos and plants through irradiated pollen technique in squash (Cucurbita pepo L.)

The influence of gamma ray doses (25, 50, 75, 100, 200, 300 and 400 Gy) and genotypes (Eskenderany F-1, Acceste F-1, Sakiz, Urfa Yerli) on the induction of haploid embryos obtained by irradiated pollen technique was studied in squash (Cucurbita pepo L.). Different shapes and stages of embryos were derived from seeds extracted from fruits harvested 4-5 weeks after pollination. As a result of the present study, haploid embryos and haploid plants were obtained, with haploid production strongly influenced by gamma ray doses, embryo stages and genotypes. Gamma ray doses of 25 and 50 Gy gave the highest parthenogenetical response. All of the point shape, globular shape, arrow tips and stick-shaped embryos developed into haploid plants. However, only 53.8% of torpedo and 23.1% of heart-shaped embryos gave haploid plants. In contrast, cotyledon-shaped and amorphous-shaped embryos produced only diploid plantlets. The number of embryos per 100 seeds was the highest in 'Eskenderany F-1' and 'Sakiz' genotypes. After in vitro culture, a total of 93 haploid plantlets were obtained.