Researches on haploid embryo induction and plant obtention in squash (Cucurbita pepo L.)

ABSTRACT PhD THESIS RESEARCHES ON HAPLOID EMBRYO INDUCTION AND PLANT OBTENTION IN SQUASH (Cucurbita pepo L.) Ertan Sait KURTAR DEPARTMENT OF HORTICULTURE INSTITUTE OF NATURAL AND APPLIED SCIENCES UNIVERSITY OF ÇUKUROVA Supervisor. Assoc. Prof. Dr. Nebahat SARI Year: 1999, Pages: 203 Jury : Assoc. Prof. Dr. Nebahat SARI Prof. Dr. Kazım AB AK Prof. Dr. Ercan ÖZZAMBAK Derivation parthenogenetic haploid embryos with different doses (25, 50, 75, 100, 200, 300 and 400 Gy) gamma of Co60 irradiated pollen in 4 squash genotypes (Eskenderany Fi, Acceste Fi, Sakız and Urfa Yerli), regeneration of these embryos, confirmation of the chromosome level with chromosome counting and other techniques (stomatal and morphological screening) were investigated. In addition, the effect of pollination with different species pollens; pollen treatment by toluidin blue, colchicine or water and anther and ovule cultures had been studied. According to the results, pollination with only 25 and 50 Gray doses irradiated pollen had an effect on induction haploid embryos. Different species pollens and other type of pollens hadn't stimulating haploid embryos, anther and ovule cultures hadn't gave haploid plants. The genotypes had important effect on irradiated pollen techniques; 43 haploid plants of Eskenderany Fi genotype, 27 haploid plants of Sakız genotype, 13 haploid plants of Urfa Yerli genotype, 10 haploid plants of Acceste V\ genotype and totaly 93 haploid plants were produced. The best pollination period of Samsun region was in June and September. The ploidy levels of plants had changed according to embryos stages. 0.5 % dose colchicine-4 hours treatment was the most suitable for the obtaining dihaploid lines. Key Words: Squash, irradiated pollen, haploidy. VI