Effect of 6-BA on Physiological Changes in Two Palm Seedlings Under Varied Temperaures

The effects of 6-benzylaminopurine (6-BA) on several physiological indexes of Caryota mitis and C. obtusa seedlings treated at varied temperatures were conducted, the leaves of the two palm species were sprayed with 0, 25, 50 and 100 mg · L−1 6-BA solutions, the activities of superoxide dismutase (SOD), peroxidase (POD), and the contents of malondialdehyde (MDA), proline, soluble protein, chlorophyll and chlorophyll a/b were determined under 25°C, 5°C and 25°C for 24 h, respectively. The dynamics of a series of important physiological components derived from the leaves were studied. It was indicated that all the above mentioned physiological indexes varied with different concentrations of 6-BA and temperature. The fuzzy comprehensive evaluation values for different concentrations of 6-BA at the recovery temperature 25°C were 0.33, 0.28, 0.92 and 0.33, respectively for C. mitis, and 0.20, 0.49, 0.56 and 0.63, respectively for C. obtusa. It was concluded that leaves sprayed with different concentrations of 6-BA could affect the cold tolerance of palm seedlings. The optimal concentration of 6-BA was different for different palm species.