Abstract:
In order to investigate the effects of spraying exogenous gibberellin (GA3) on the growth and physiological status of
Taxus wallichiana. 5-year-old potted cuttings of
Taxus wallichiana were used as experimental materials, and the leaves were sprayed with gibberellin of 0, 20, 40, 60, 80, and 100 mg·L
−1 for 2 months. The plant height and ground diameter were measured regularly, and the contents of chlorophyll, malondialdehyde (MDA), proline (Pro) and superoxide dismutase (SOD) in leaves were measured at the end of the test. The results showed that: (1) With the increase of GA3 concentration, the growth of plant height and ground diameter of
Taxus wallichiana showed a trend of first increasing and then decreasing, and the growth effect of 60 mg·L
−1 treatment being was the best. (2) With the increase of GA3 concentration, the contents of chlorophyll a, chlorophyll b, and total chlorophyll showed a trend of first increasing and then decreasing, with the highest content of chlorophyll a and total chlorophyll was observed in the 60 mg·L
−1 treatment, and the highest content of chlorophyll b was observed in the 40 mg·L
−1 treatment, while the chlorophyll a content was much higher than the chlorophyll b content. (3) With the increase of GA3 concentration, the content of MDA increased first and then decreased, and the treatment of 60 mg ·L
−1 was the highest, indicating the most severe stress. The contents of Pro and SOD decreased first and then increased, and both of which were the lowest in the treatment of 60 mg·L
−1. In summary, the resluts showed that spraying exogenous GA3 could promote plant growth and chlorophyll accumulation during the transitional period from growth to dormancy of
Taxus wallichiana. However, excessive concentration could stress the plant growth, leading to the increase of MDA content and the decrease of Pro and SOD contents in leaves, which would create stress and weaken stress resistance.