长期喷施ABA对云杉幼苗生长和生理特性的影响

采用单因素盆栽实验, 通过叶面喷施5、10、15和20 mg.L-1 4个浓度的ABA溶液, 研究了长期外源ABA处理对云杉(Picea asperata)幼苗生长及生理特性的影响。5年的研究结果表明: 长期不同浓度ABA处理显著影响了云杉幼苗的多种生长及生理生化指标。当ABA浓度为5、10和15 mg.L-1时有利于云杉幼苗根重、茎重和总生物量的积累, 并且提高了叶片中可溶性蛋白和脯氨酸的含量, 降低了MDA含量; 20 mg.L-1ABA处理使幼苗的叶重、总生物量、脯氨酸及可溶性糖含量显著下降,明显增加了叶片中MDA含量。此外, 各浓度ABA处理均显著降低了云杉幼苗的株高、叶绿素含量以及SOD和APX活性。本研究结果显示, 长期ABA处理对云杉幼苗生长和生理特性的影响与所喷施的ABA浓度有关, 长期高浓度ABA(20 mg.L-1)处理不利于云杉幼苗生长。

Growth and Physiological Responses of Picea asperata Seedlings to Long-term Abscisic Acid Application

The paper describes the effects of long-term application of abscisic acid (ABA) at different concentrations in Picea as perata at the Maoxian Ecological Experimental Station of Chinese Academy of Sciences during a 5-year pot experiment. Longterm exogenous ABA application significantly affected the height and biomass (root,stem, and leaf weight); chlorophyll, osmoprotectant (proline, soluble sugar, soluble protein), and malonic dialdehyde (MDA) content; and antioxidative enzyme activity. ABA treatments at 5 mg.L-1, 10 mg.L-1 and 15 mg.L-1 significantly improved root weight, stem weight and total biomass; increased the soluble protein and proline content; and reduced MDA content in needles. However, the highest application of ABA (20 mg.L-1) caused a significant reduction in accumulation of chlorophyll, free proline and soluble sugar and a significant increase in MDA content in needles. These results suggest that the effects of exogenous ABA application on Picea asperata is concentration dependent, and longterm high exogenous ABA (20 mg.L-1 ) is unfavorable for plant growth. Moreover, the height, chlorophyll content, and activities of superoxide dismutase and ascorbate peroxidase were significantly reduced with application of exogenous ABA.