关键词: 千年桐, 幼苗, 稀土, 叶面喷施, 生长, 生理指标

Abstract:

The seedlings of Vernicia montana derived from seeds soaking with water (the first group)or 300 mg·L^-1 mixed nitric-acid rare earth solution (the second group) were treated with various concentrations of mixed nitric-acid rare earth solution by foliage spraying. The results showed that the seedling heights sprayed with 100 和 1 000 mg·L^-1 of the first group and with 50 和 100 mg·L^-1 of the second group were significantly higher than the controls, and the diameter at ground level sprayed with 300 mg·L^-1 of the second group was significantly greater than the control, being 26.92% more than the latter; except for spraying with 0 mg·L^-1 and 700～1 500 mg·L^-1 of the second group, the seedling dry weight above ground of others was 29.13%～73.91% greater than the control, whereas the seedling dry weight under ground of others was 20.78%～116.88% greater than the control; the contents of chlorophyll a and chlorophyll b for all spraying seedling were 91.67%～191.67% and 87.5%～306.25% greater than the control, respectively, and soluble proteins and soluble sugars were 16.00%～179.78% and 10.73%～105.65% greater than the control, respectively. Compared with the control, the activity of SOD tended to increase, whereas the contents of MDA decreased. These indicated that spraying leaves with optimum concentration of mixed nitric-acid rare earth solution could markedly promote the growth of seedlings and improve resistance ability of V. montana seedlings to bad environment. On the whole, the effects of spraying the leaves of seedling with 50～500 mg·L^-1 mixed nitric-acid rare earth solution, which were derived from seeds soaking with 300 mg·L^-1 mixed nitric-acid rare earth solution, were good.

Key words: Vernicia montana, seedlings, rare earth, foliage spraying, growth, physiological index