紫穗槐幼苗不同生长阶段叶水势对干旱胁迫与复水的响应特征

为揭示紫穗槐（Amorpha fruticosa）幼苗叶水势对土壤干旱与复水环境的响应特征,本研究通过盆栽试验,研究了土壤干旱胁迫及复水对紫穗槐幼苗不同生长阶段叶水势的影响。结果表明：土壤水分、干旱历时和生长阶段3个因素以及各因素间的相互作用对紫穗槐幼苗叶水势均有极显著影响（P<0.01）;随着干旱程度加剧,幼苗叶水势呈下降趋势,水分胁迫指数呈上升趋势;40.00%土壤相对含水量下的幼苗叶水势下降幅度达到最大,其中干旱15 d的生长初期和生长中期以及干旱30 d的生长后期的叶水势分别比对照下降了0.71 MPa,1.12 MPa和0.58 MPa;复水后,叶水势出现补偿效应,随着复水后时间的延长,幼苗3个生长阶段叶水势逐渐恢复,恢复速率与干旱程度、干旱历时和生长阶段密切相关,但均在复水72小时后恢复到接近对照水平。

Response Characteristics of Leaf Water Potential in Different Growth Stages of Amorpha fruticosa Seedlings to Drought Stress and Re-watering

In order to reveal the response characteristics of Amorpha fruticosa seedlings leaf water potential at different growth stages to soil drought and re-watering environment,a pot experiment was carried out. The results showed that soil moisture,drought duration,growth stage,as well as the interaction among the three factors had significant effects on leaf water potential of A. fruticosa seedlings (P<0.01). With the aggravation of drought,the seedling leaf water potential decreased while the water stress index increased. Under the condition of 40% soil relative water content,the leaf water potential of seedlings decreased the most. In addition,in the initial and fast growth period of 15 days drought and in late growth stage of 30 days drought,the leaf water potential decreased by 0.71 MPa,1.12 MPa and 0.58 MPa,respectively. The leaf water potential had a compensating effect after re-watering. With the extension of the time after re-watering,the leaf water potential of the three seedlings growth stages gradually recovered. The recovery rate was closely related to drought degree,drought duration and growth stage. However,all indexes recovered to close to the control level after 72 hours of re-watering.