干旱胁迫对3种园林绿化树种幼苗生理指标的影响

以小叶榕、海南蒲桃、红桂木3种公路绿化树种幼苗为试材，人工模拟干旱胁迫环境，通过测定各树种幼苗叶片的生理指标，探讨干旱胁迫对3种幼苗生长的影响。研究表明：叶片组织含水量呈下降趋势，而可溶性糖含量呈上升趋势；小叶榕和红桂木幼苗叶片叶绿素含量先升后降，海南蒲桃逐渐上升；小叶榕和红桂木幼苗的蛋白质含量显著增加后保持稳定，海南蒲桃幼苗先升后降；小叶榕和红桂木幼苗的脯氨酸含量上升，海南蒲桃缓慢下降；小叶榕幼苗叶片的SOD活性先降后升，海南蒲桃幼苗逐渐上升，红桂木幼苗先升后降；小叶榕幼苗的MDA含量稳定，海南蒲桃和红桂木幼苗上升。主成分分析结果显示，3种幼苗的抗旱性为红桂木>海南蒲桃 >小叶榕。

Physiological Changes of Three Greening Seedling Species under Drought Stress

Studies were conducted on seedlings of Ficus microcarpa, Syzygium hainanense and Artocarpus nitidus ssp. lingnanensisunder simulated drought environment to study their physiological changes and then explore the effects of stress on the growth of seedlings. The result showed that, under drought stress, tissue water contents of the three seedlings tended to decreased, whereas thesoluble sugar content tended to increased; chlorophyll content of F. microcarpa and A. nitidus ssp. lingnanensisincreased first and decreased afterwards and S. hainanense increased gradually; protein content of F. microcarpa and A. nitidus ssp. lingnanensis increased and then kept steady, and S. hainanenseincreased first and decreased afterwards; the content of free proline of F. microcarpa and A. nitidus ssp. lingnanensis increased, whereas S. hainanense decreased slowly; the activity of SOD of F. microcarpa first decreased and increased afterwards, S. hainanense increased gradually, and A. nitidus ssp. lingnanensis increased first and decreased afterwards.The contents of MDA of F. microcarpa kept steady, whereas S. hainanense and A. nitidus ssp. lingnanensis increaseds. Principal component analysis indicated that drought resistance of the three seedling types was in the order of A. nitidus ssp. lingnanensis﹥S. hainanense﹥F. microcarpa.