Effect of Priming Treatment on Germination at Stressful Temperatures, Fatty Acid, Sugar Content and Enzymatic Activity of Pepper Seeds

This research was conducted to investigate the effects of priming (controlled hydration at 25°C for 48 h) on germination at stressful temperatures (low 15°C and high 35°C), sugar content, total oil, fatty acid composition and enzymatic activities of pepper (Capsicum annuum L.) seeds in two consecutive runs. The experiments were conducted on pepper cultivars of Çorbacı, Sera Demre 8 and Yalova Yağlık. Results revealed that priming enhanced germination of seeds of all cultivars at stressful temperatures. The highest increase in germination was determined in cv. Çorbacı at (15°C) with 12% and 35°C with 21%. Priming decreased total oil content dependent upon cultivars. The highest decrease in oil content by priming was determined in Demre with 2.5-3.5%. On the other hand, fatty acid composition was not changed and the highest fatty acid of the seeds was linoleic acid (78.9%) followed by palmitic (9.16-11.79%) and oleic (7.28-11.40%). Priming resulted in decrease in sucrose which declined from 0.599% to 0.390% in Yalova Yağlık. Glucose was detected as trace in both control and primed seeds. The most important effects of priming on enzymatic activities were recorded in catalase which increased remarkably with priming in both runs. Catalase activity was measured in primed seeds with 11.2 μmol min^-1 g^-1 and in control with 9.3 μmol min^-1 g^-1 in run 1. They were determined as 16.6 μmol min^-1 g^-1 and 9.6μmol min^-1 g^-1 in run 2, respectively. Even though not the same extent, priming also increased ascorbate peroxidase and superoxide dismutase activities.