Effect of Temperature Pre-Treatment and Light on Embryogenesis and Callus Induction in Anther Culture of Cucumber

The aim of this study was to investigate the effects of hormonal compositions and concentrations, temperature and light pre-treatments in changing the biological pathways and moving toward callugenesis, embryogenesis and regeneration in cucumber anther explants. Two seperate factorial experiments were conducted in completely randomized design with three replications on open pollination Isfahan native cucumber and greenhouse inbred line. Factors consisted of tempreture (4°C cold and without cold pretreatment (fresh flower)), Light treatment (brightness and darkness) and different hormone compositions and concentrations including KIN (1 to 2.5 mg/L), BAP (0.1 to 3.5 mg/L) and 2.4-D (1 to 3.5 mg/L) at five levels. The results showed the superiority of the fresh flower in cold pre-treatment for embrygenesis and callugenesis in inbred line, and for callugenesis in native cultivar. Darkness treatment caused a significant increasing in callugenesis and callus diameter of inbred line, however did not significant effects on native cultivar. The combination of BAP and 2,4-D hormones at a rate of 3.5+1mg/L (in both genotypes) caused the highest induction of embryogenesis and callugenesis. Embryogenesis was affected by studied factors in inbred line, however these factors did not have significant effects on embryogenesis in native cucumber. Triple interaction of temperature, light and hormonal compositions in culture media showed that in order to obtain the highest embryogenesis, callus induction and callus diameter, use of fresh flowers and 2,4-D+BAP hormones (3.5+1 mg/L) are suitable in anther culture of cucumber. The conditions of lightness and darkness did not play important role in embryogenesis.