Mansour Mohammadian, Behroz Goleen, Z Khosravi Lorgani,
Volume 12, Issue 3 (11-2012)
Abstract
Citrus fruits are tropical and sub-tropical crops. The main problem in sub-tropical area is chilling and frost damage. Regarding the sensitivity of citrus fruit to low temperature and the conjunction of the fruit harvest season with low temperature, the investigation of the physiological impacts of low temperature treatments are very important. In this study, flavedo tissue of five cultivars of citrus fruit was examined to compare some enzymatic antioxidants activities including Superoxide dismutase (SOD), Ascorbate peroxidase (APX), peroxidase (POD) and Catalase (CAT) under various cold treatments, i.e. control (~15), 3, 0, -3 and -6 °C in two stages of before and after ripening of the fruits. The high activity of SOD enzyme in the flavedo tissue of the examined cultivars indicated that this tissue is the first defensive line of the fruits facing low temperatures treatments. The activity of CAT enzyme in the flavedo tissue of Sanguinello before and after ripening stages was higher in all low temperature treatments compared with other cultivars. Unshiu and Local Orange had maximum and minimum activity of APX enzyme, respectively in both stages. Also, Unshiu, Sanguinello and Local lemon showed increasing activity of POD enzyme by decreasing temperature
