Comparative Study on Cold Resistance Physiology of Red Pulp Pitaya and White Pulp Pitaya

Abstract

The red pulp pitaya variety ’Taiwan No. 2’ and the white pulp pitaya variety ’white crystal’ were used as experimental materials, which were cold stressed at low temperature of 3 °C for 48h, 96h, and recovering at room temperature after 96h cold stress for control. The relative conductivity (REC), malondialdehyde content (MDA), soluble sugar content (SS), soluble protein content (SP), free proline content (Pro), activity of superoxide dismutase (SOD), and catalase (CAT) were determined and the cold resistance were analyzed. The results showed that, after cold stress, the SP, Pro content and SOD and CAT activities of ’White Crystal’ pitaya were higher than that of ’Taiwan No. 2’ pitaya. It showed that the cold resistance of ’White Crystal’ white pulp pitaya was stronger than that of ’Taiwan No. 2’ red pulp pitaya.