Obtention of haploid plant in watermelon genetic resources by ovule-ovary culture method

This study aimed to obtain haploid plant with the method of ovule-ovary culture using genetic resources of watermelon. In this study, four genotypes Kar 23, Kar 37, Kar 116 and Kar 147 were used. Different doses of 2,4-D (2.5 mg/l, 5 mg/l) and TDZ (0.5 mg/l, 1 mg/l) hormones and polyamines (500 µM/l of putrescine and spermidine) were added into medium separately and together. Totally 16 different media combinations supplemented with 8 g/l agar and 30 g/l sucrose were used. Two different experiments were established in this study. In the first experiments, female flowers were collected 1 day before anthesis ovaries and excised ovules were cultured after heat shock pre-treatment at 35 °C in dark for 3 days and then they were placed in climate controlled chambers (having 3000-4000 lux light density). In the second experiments, female flowers were collected 2 days before anthesis, ovaries and excised ovules were cultured after and then transferred into climate controlled chambers. According to obtained results, different level of ovule-ovary development and the callus formation were observed at different rates among genotypes. Embryo and plantlet developments were observed in the mediums which contains 2.5 mg/l 2,4-D + 1 mg/l TDZ + 500 µM SPD, 2.5 mg/l 2,4-D + 1 mg/l TDZ + 500 µM PUT and 5 mg/l 2,4-D + 0.5 mg/l TDZ for genotypes of Kar 37 and Kar 147 but full plant development from these plantlets have not been obtained. Keywords: Watermelon (Citrullus lanatus L.), genetic resources, haploid, spermidine, putrescine