Effect of different storage conditions on germination and some biochemical characteristics of castor bean (Ricinus communis) seed

In order to evaluate the effect of different storage conditions on seed germination and some biochemical characteristics of castor bean (Ricinus communis), a factorial experiments on the bases of completely randomized design with three factors included of storage temperature, seed moisture content (SMC) and storage duration in four replications was done in the seed laboratory of Faculty of Agriculture and Natural Resources, University of Tehran, Iran in 2014. Experimental factors were including five storage temperatures (5, 15, 25, 35 and 40oC), five SMC levels (3.53, 6, 9, 12 and 15%) and six storage duration (30, 60, 90, 120, 150 and 180 days). The results showed that in all storage temperatures germination percentage trend was descending with increasing storage temperature and duration. In all studied storage temperature, the seeds stored in SMCs of 3.53 and 15% showed the highest and lowest germination, respectively. However, the change in seed electrolyte leakage index was ascending by increasing the temperature and SMC. Also, with increasing storage duration, temperature and SMC, seed total protein content, enzymes activity of catalase and superoxide dismutase and ascorbate peroxidase decreased and malondialdehyde content (MDA) increased. Therefore, decrease in germination index and increase in electrical conductivity could be due to decline in antioxidant activities and increase in MDA content.