Improved tolerance toward low temperature in banana (Musa AAA Group Cavendish Williams)

To further understand the physiological mechanisms of cold-tolerance in banana plants, the responses of four introducing cultivars (cv.) W811 (via long-term cold adaptation), PB, BJ10 and BJ11 to low-temperature stress (LT) were investigated. LT caused increased malondialdehyde (MDA) content, elevated contents of hydrogen peroxide (H2O2) and superoxide radical (O2−), and decreased photochemical efficiency (Fv/Fm) and net photosynthetic rate (Pn) in the leaves of four banana cultivars, but cv. W811 showed better LT tolerance than the other three cultivars. After 72 h of LT, four key antioxidative enzymes in the four cultivars showed different responses. Compared to controls, superoxide dismutase (SOD) activities in the four cultivars showed a significant decrease and W811 had the smallest amount of decrease. Catalase (CAT) activities showed a significant decrease. Peroxidase (POD) activities kept relatively higher activities and showed no significant changes (P > 0.05) in W811, BJ10 and BJ11 whereas that in PB showed a significant increase (P < 0.001). Ascorbate peroxidase (APX) activities in W811 and PB showed no significant changes (P > 0.05). Our results showed that higher cold-tolerance in cv. W811 may correlate with the long-term cold adaptation of the antioxidative enzymes such as SOD, POD and APX that alleviate oxidative stress caused by LT.

► Four banana cultivars including W811 (via long-term cold adaptation) were studied.
► Relationship between cold-tolerance and long-term cold adaptation was investigated.
► It can promote banana productivity via cultivating cold-resistant variety.
► Cold-tolerance may be related to long-term cold adaptation of antioxidant enzymes.