The effect of the donor plant's age and season effect on haploid embryo and plant formation in cucumber (Cucumis sativus L.) via gynogenesis

Cucumber is one of the most important vegetables in the group of vegetables with high commercial value, used for both fresh consumption and industrial purposes. It is important to obtain homozygous cucumber lines in a short time in breeding studies carried out to develop high quality commercial cucumber varieties. This is achieved by haploid studies. In this study, the effects of donor plant age, the season in which the donor plant was grown, the ovarium growth temperature in the greenhouse and the donor plant genotype on the gynogenesis methods in cucumber were investigated. Commercial F1 hybrid cultivars of Ufuk, Meriç and Sedir were used as plant material in the study, and embryo induction was provided in MS + 1: 10; 2,4-D: Kinetin + 30 g L-1 sucrose-containing medium. Then ovaries were taken into MS + 1: 4; NAA: BAP + 30 g L-1 nutrient medium containing for embryo regeneration. To determine the effect of the age of the donor plants and the effect of the growth temperature of the ovaries in the greenhouse, the weekly embryo and plant numbers data were collected. Then the embryo induction rates, plant formation rates, and plant regeneration rate according to the number of embryos were calculated. In addition, the effect of the growing season of the donor plant was evaluated according to the total results obtained from the plants grown in four different seasons. At the end of the study, it was determined that the dependence of the genotypes on the donor plant age differs according to the genotypes and the Sedir cultivar was the genotype most affected by the plant age factor. Considering all genotypes, it was seen that productive results were obtained in embryo and plant production up to 7 weeks. When evaluated in terms of season, it was seen that the Spring season was more effective in terms of haploid embryo and plant production compared to the Fall season. It has been determined that the ovarium greenhouse growth temperature is an important factor for haploid embryo and plant production, and it is positively affected by the increase in the maximum and minimum temperature difference of the Ufuk cultivars. Apart from all observation criteria, it was determined that embryo promotion and plant yield rates increased in Meriç and Ufuk cultivars under short day conditions. It was found that the effect rate of factors related to the donor plant growing conditions was low during the regeneration from embryo to plant. In the study, an average of 112.69%embryo formation was achieved from all genotypes, and the plant formation rate was recorded as 39.35%. According to the embryos obtained, the regeneration rate of embryos into plants is 34.91%. Ploidy levels of 43 plants that developed only in the last season were determined by flow cytometry method and 17 haploid, 21 diploid and 5 myxoploid plant formations were detected.