Effect of different pollination dates with irradiated pollens on fruit set, haploid embryo induction and plant obtention in Turkish (Kirkagac, Yuva and Hasanbey) melons

Dihaploidization is a technique which allows to develop 100% homozygous lines. Irradiated pollen technique provides successful results in melon and 100% homozygous inbred lines can be obtained within 18 months. Turkey is the second largest melon producer country after China with 1.8 million tons of production on 116.000 ha area. Most of the Turkish melons are odourless, winter types belonging to Cucumis melo var. inodorus. In this group; Kirkagac, Yuva and Hasanbey are the most important genotypes which are mainly produced in Aegean and Central Anatolia regions. Several different factors restricts the melon production, however Fusarium wilt and downy mildew are the most considerable. Both diseases cause significant damages on fields which Kirkagac, Yuva and Hasanbey are cultivated. The objective of this study was to determine the effect of different pollination periods (10th-17th April, 18th-25th April, 26th-03rd April and 04th-11th May) with the irradiated pollen on fruit setting, haploid embryo induction and haploid plant obtention. For this aim, 1188 female flowers for Kirkagac and 261 female flowers for Yuva-Hasanbey were pollinated. Rate of the fruit set was 42 and 46% respectively. In total 625 (504 Kirkagac and 121 Yuva-Hasanbey) parthenogenetic fruits were harvested, 564 677 seeds were extracted and 1255 embryos (1151 heart shaped, 76 globular and 28 torpedo) were rescued. According to the research results, the most convenient pollination period was 04th-11th May with the rate of 73.52% (for Kirkagac) - 91.91% (for Yuva-Hasanbey) fruit setting. The number of rescued embryo per fruit was 1.46-1.54 for 10th-17th April, 2.17-2.37 for 18th-25th April, 4.01-2.50 for 26 th-03rd May and 1.12-4.50 for 04st-11 th May for Kirkagac and Yuva-Hasanbey group respectively. Eventually, 860 (681 haploid plants for Kirkagac and 179 haploid plants for Yuva-Hasanbey) haploid plants were obtained in this study