DORMANCY INDUCTION IN PEPPER SEEDS WITH TETCYCLACIS

Abstract

Seeds of six pepper (Capsicum Anuum L.) cultivars were treated with tetcyclacis (TCY), an inhibitor of the oxidative steps from ent-kaurene to ent -kaurenoic acid in the gibberellin biosynthetic pathway. Seeds were soaked in TCY solutions for 24h in darkness at 25° to 30°C, washed with water and then air-dried. Various concentrations of TCY were needed to induce dormancy in `Yolo Wonder', `Cayenne', `California Wonder', `Sweet Banana', `El Paso' and `Anaheim'. TCY-treated seeds were germinated in water and in various concentrations of GA4+7 in darkness. Dormancy induced by TCY was released with 10 μM GA4+7. The germination inhibitor, abscisic acid (ABA), failed to induce dormancy in pepper seeds even when treated at a concentration of 400 μM for up to 14 d. Similar results were obtained with tomato seeds and will be reported elsewhere. The results indicate that the absence or the unavailability of GA rather than the presence of ABA determines the dormant state in pepper seeds.