effects of putrescine and chlormequat pre-flowering treatment on embryo rescue technique success in diallele crosses of grape cultivars flame seedless, perlette and yaghooti

seedless grapes are widely grown all over the world. embryo rescue technique proved to be able to overcome the problem of embryo abortion in seedless grape breeding program. since, the efficiency of this technique is not desirable, so a lot of efforts have been done in different directions in order to improve this technique. this study was conducted in two separate experiments in which chlormequat and putrescine were employed in different experiments. cultivars of yaghooti, flame seedless and perlette were used as both female and male parents in both experiments. clusters sprayed with different concentrations of chlormequat and putrescine 14 days before blooming. ovules were excised from berries 45 days after pollination and cultured in nn medium supplemented with 3.0% sucrose, 0.2% activated charcoal and 6% agar. embryos were removed from the ovules after 10 weeks and transferred onto ms medium supplemented with 2.0% sucrose, 0.2% activated charcoal and 6.5% agar. the results showed maternal and paternal genotypes, pre-treatment with chlormequat and putrescine had positive and significant effect on endosperm and embryos development, embryos germination and plant production. the use of cv. perlette as female parent, cv. yaghooti as male parent and pre-treatment with chlormequat and putrescine at 100 and 30 mg/l increased the percentage of measured traits.