干旱胁迫及复水对“雪不凋”萱草生理特性的影响研究

Effects of Drought Stress and Rewatering on the Physiological Characteristics of H.'Xuebudiao'

以人工栽培的“雪不凋”萱草为试验材料,采用盆栽控水法,测定了不同程度干旱胁迫及复水后“雪不凋”萱草的生理生化指标,分析了不同处理间各指标的差异。结果表明:干旱胁迫过程中,叶片相对电导率、丙二醛、游离脯氨酸均呈持续上升的变化趋势;可溶性蛋白和超氧化物岐化酶(SOD)活性则呈先升后降的变化趋势;叶绿素在轻度干旱条件下呈先升后降的变化趋势,在重度干旱下则持续下降;复水7 d后,丙二醛、SOD活性均恢复至正常水平,其余指标的重度干旱及持续干旱胁迫都不能完全恢复至对照水平。并得出了各生理指标通过协同作用,为萱草应对干旱环境起到保护作用;干旱胁迫的程度不同,萱草复水后各指标恢复能力和恢复程度各异,总体复水后的恢复能力为轻度干旱>中度干旱>重度干旱>持续干旱的结论。研究干旱胁迫及复水对萱草生理生化的影响,可为“雪不凋”萱草的抗旱栽培及水分高效利用提供理论依据。

The effects of drought stress and rewatering on the physiology and biochemistry of Hemerocallis were studied to provide a theoretical basis for the drought-resistant cultivation and efficient water use of H.'Xue bu diao'.The artificially cultivated H.'Xue bu diao'was used as the test material,and the potted water control method was used to measure the physiological and biochemical indexes of H.'Xue bu diao'after different degrees of drought stress and rewatering,and to analyze the differences of each index among different treatments.During drought stress,the relative conductivity of leaves,malondialdehyde and free proline all showed a continuous increasing trend;soluble protein and superoxide dismutase(SOD)activities showed a trend of first increasing and then decreasing;after 7 days of rehydration,the activities of MDA and SOD returned to normal levels,and the other indicators showed a trend of severe drought and continuous decline.Neither drought stress fully recovered to control levels.Through synergistic action,each physiological index plays a protective role for Hemerocallis to cope with the drought environment;the degree of drought stress is different;the recovery ability and degree of recovery of each index after rewatering are different and the overall recovery ability after rewatering is mild drought>moderate severe drought>severe drought>persistent drought.