Effect of pre-bloom sprays of Benzyladenine on the Development of Ovule and Embryo Rescue of Two Iranian Stenospermic Grape (Vitis vinifera L.)

One of the main objectives of table grape breeding programs is producing new seedless hybrids with large, firm, high flavor berries and consistent with consumers taste. Abortion of zygotic embryo in seedless grapes largely limits the efficiency of seedless cultivars breeding. Since cytokinins are known to increase the sink strength of seeds for assimilates, the present investigation was conducted to study the influence of pre-bloom sprays of benzyladenine (BA) on ovule development and embryo rescue of two stenospermic grape cultivars (Askari and White Seedless).Concentrations of BA were 0, 60 and 100 ppm. Ovules of White Seedless, 20 days and Askari 40 days after flower opening were dissected out of berries and then cultured in Nitsch & Nitsch medium containing 1μM GA3, 1μM NAA, 2 g/l activated charcoal, 20 g/l sucrose and 8 g/l agar. Evaluated characteristics were ovule browning, callusing and germination. BA Spraying had no significant effect on ovules blacking but percentage of browned ovules were significant between examined cultivars and the highest ovule browning were observed in White Seedless cultivar. Effect of BA sprays whit 60 and 100 ppm concentrations were significant on callusing and ovules germination. Results showed the significant effect of cultivars on the percentage of germination ovules. Ovules germination was 23.71% in Askari cultivar and 14.44% in White Seedless. Finally pre-bloom sprays of benzyladenine (BA) increase successfully of embryo rescue technique in Askari and Bidaneh sefid Cultivars.