外源硼酸钠对桂花幼苗抗寒性的影响

摘要

采用人工气候室模拟低温环境, 研究不同浓度的外源硼酸钠对桂花幼苗抗寒性的影响. 结果显示: 在4℃低温胁迫下, 随时间的延长, 外源硼酸钠处理桂花叶片MDA含量和可溶性蛋白含量逐渐升高, 游离脯氨酸、 可溶性糖含量以及SOD、 CAT酶活性变化趋势为先上升后下降, POD活性持续上升; 外喷0.5 %~1 %浓度的硼酸钠可显著减少桂花叶片MDA含量, 增加游离脯氨酸, 促进可溶性蛋白和可溶性糖的积累, 提高SOD、 POD、CAT抗氧化酶活性; 0.5 %浓度的硼酸钠可促进植株纵向生长, 1 %~2 %浓度的硼酸钠对低温胁迫下桂花幼苗纵向生长产生一定的抑制作用, 且浓度越高抑制性越强. 低温胁迫对桂花幼苗产生一定程度的伤害, 适当浓度外源硼酸钠处理可以有效缓解低温胁迫对桂花叶片的伤害, 提高桂花幼苗的抗寒性.%The effect of different concentrations of exogenous sodium borate on cold resistance of sweet-scented Os-manthus fragrans seedlings was studied by low temperature simulation in artificial climate chamber , and the results showed that, for the Osmanthus fragrans leaves treated by exogenous sodium borate, the MDA content and soluble protein content gradually increased in the low temperature stress under 4℃with the time extension , and the chan-ging tendency of the free proline content, soluble sugar content, and the enzyme activity of SOD, CAT were in-crease at the beginning then decrease later.The POD activity increased continuously.Osmanthus fragrans leaves sprayed by 0.5 %~1%concentration of boric acid sodium showed a significant reduce of MDA content , free pro-line increase , facilitated accumulation of soluble protein and sugar , and improved activity of antioxidant enzymes of SOD, POD, CAT.0.5 %concentration of sodium borate could also promote the plant vertical growth.1 %~2 %concentration under low temperature stress constraint the longitudinal growth of Osmanthus fragrans seedlings, and the higher the concentration the more intensive inhibitory effects.This study showed that low temperature stress had certain damages on Osmanthus fragrans seedlings , and the appropriate concentration of exogenous sodium bo-rate treatment could effectively alleviate the damage of low temperature stress on leaves of Osmanthus fragrans, and could improve its cold resistance .