Effect of Preflowering Cycocel Application on Development of Ovule and Subsequent Embryo Rescue of Two Iranian Stenospermic Grapes

Abortion of embryoes in stenospermocarpic grapes limits the efficiency of breeding of seedless cultivars. Plant growth regulators are one of the important factors to promote embryo germination in stenospermic grapes. Cycocel is growth inhibitor which reduces sitmulative effects of gibberellic acid and improve embryo rescue. The present study was carried out in 2010, to investigate the effects of cycocel on grapevines in field condition, on ovule development and subsequent embryo rescue of two stenospermocarpic grape cultivars (‘Askary’ and ‘Bidanh Safid’). Concentrations of cycocel were 0, 200 and 500 ppm. Length of berries and ovules were measured in ‘Bidaneh Safid’ and ‘Askary’, after 20 days and 40 days of flower opening, respectively. Ovules were dissected out from berries were cultured in Nitsch & Nitsch medium containing 1μM GA3,1μM NAA, 2 gL-1 activated charcoal, 20 gL-1 sucrose and 8 gL-1 agar. A factorial experiment based on completely randomized design with five replications was used. Measured characteristics were length of berries and ovules, percentage of browned, callused and germinated ovules. Results showed that, length of berries and ovules, and also percentage of germinated ovules in ‘Askary’ cultivar was higher than ‘Bidaneh Safid’ cultivar. The results also showed that effects of of cycocel were significant on length of berries and ovules, and also on percentage of callused and germinated ovules at 1% level, but were not significant on percentage of browned ovules. Application of cycocel at 200 mgl-1 significantly increased length of berries and ovules, percentage of callused and germinated ovules. Application of 200 mgl-1 cycocel also resulted in germination of 28.8% ovules in ‘Askary’ cultivar.