Authors: Kazım ABAK, Nebahat SARI, Mustafa PAKSOY, Hale YILMAZ, Hakan AKTAŞ, Candaş TUNALI
Abstract: In this study, 18 melon cultivars which belong to 3 different botanical varieties (var. inodorus, var. reticulatus and var. cantalupensis) of Cucumis melo were tested in order to investigate genotypes effect on haploid embryos induction by pollination with pollens irradiated with Co60 gamma ray. Embryos were obtained from gamma ray. Embryos were obtained from 14 genotypes belong to 3 different botanical varieties and these embryos were regenerated into plantlets using in vitro embryo rescue method. In order to obtain dihaploid plants, in vitro haploid plantlets were firstly treated with 0.5 % colchicine solution for two hours and then they were cloned with in vitro micro cutting. These dihaploid plants were acclimatizated in greenhouse conditions. The percentage of acclimatization were ranged between 57-63 % . Seeds were obtained by selfing from all plants grown in greenhouse. Ploidy levels of haploid and dihaploid plants verified using both chromosome counting (n=12) on root cells and flow cytometry on leaf cells. Also the measurement of stomata dimension and counting of chroloplast in guard cells were performed in haploid and dihaploid plants. The results showed that stoma diameter and length of dihaploids were higher than haploids at the rate of 31 % and 58 % respectively. The number of chloroplast was ranged between 6-8 in haploids and 10-12 in diploids.