干旱胁迫下白刺花幼苗根系生长和生理特性的响应

近年来干旱频发，严重限制了作物生产和植被恢复。因此，鉴定天然耐旱植物物种具有重要意义。通过对白刺花(Sophora davidii)盆栽苗干旱处理，设置4个干旱梯度，分析干旱胁迫下白刺花根系生长生理指标，发现其根系最先感知到干旱来临，其根长、表面积、体积增加，生长素、赤霉素、脯氨酸、可溶性糖以及丙二醛和过氧化氢含量上升，超氧化物歧化酶、过氧化物酶、过氧化氢酶活性下降，抗坏血酸过氧化物酶活性上升；在重度干旱下白刺花也未发生严重脱水和幼苗死亡的现象，表明其有较强的抗旱性，适合在半干旱区以及喀斯特地区的生态恢复重建与饲料开发中应用。试验阐明白刺花抗旱的适应机制，揭示白刺花抗旱能力，为白刺花在西部喀斯特地区全方位、立体式产业开发利用提供一定的参考依据。

Response of Root Growth and Development and Physiological Characteristics of Sophora davidii under Drought Stress

Droughts have been frequent in recent years,severely limiting crop production and vegetation recovery. Therefore,it is important to identify natural drought-tolerant plant species. The physiological indicators of root growth under drought stress were analyzed by setting four drought gradients in Sophora davidii potted seedlings,and it was found that the root system was the first to sense the onset of drought,and its root length,surface area,and volume increased,and the contents of auxin (IAA),gibberellins (GA₃),proline,soluble sugars and malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) contents increased,superoxide dismutase (SOD),peroxidase (POD) and catalase (CAT) activities decreased,and ascorbate peroxidase (APX) activity increased. Under severe drought,S. davidii did not suffer from severe dehydration and seedling death,indicating that it has strong drought resistance and is suitable for application in ecological restoration and fodder development in semi-arid areas as well as karst areas. The experiment elucidates the adaptive mechanism of drought resistance of S. davidii,reveals the drought resistance of S. davidii,and provides a certain reference basis for the all-round and three-dimensional industrial development and utilization of S. davidii in the western karst region.