Desiccation tolerance and antioxidant enzymatic activity in Citrus reshni seeds exposed to various drying rates

Abstract

Despite the economic relevance of Citrus reshni as a rootstock for citrus, information about the consequences of seed desiccation is scarce and controversial. Thus, our objective was to evaluate the effects of drying rates and water content on the physiological quality of and activities of catalase and superoxide dismutase antioxidant enzymes in C. reshni seeds. Regardless of the drying rate tested, seeds were very tolerant to desiccation, maintaining a high percentage of normal seedlings even when the water content was reduced to 3%. At 15 and 10% water content, however, the percentage of seeds with multiple normal seedlings reduced. Rapid-drying was more advantageous as it provided higher germinability and a lower percentage of abnormalities. Desiccation to 25% water content prior to sowing was beneficial because it increased the percentage of normal seedlings and retained the percentage of seeds with multiple normal seedlings. The best water content for storing these seeds still needs to be determined. Catalase and superoxide dismutase enzymatic activities in dried seeds are not good biomarkers to monitor the effects of drying in C. reshni seeds, although they may help understand the nature of stress that occurs during drying and influence seed behaviour during storage.