土壤逐渐干旱及复水对黑果腺肋花楸光合特性的影响

    Response of Photosynthetic Performance in Aronia melanocarpa to Drought Stress and Rehydration

    • 摘要: 【目的】探索黑果腺肋花楸对土壤干旱胁迫的响应。【方法】以两年生黑果腺肋花楸为材料,人工模拟干旱胁迫,通过盆栽试验进行土壤逐渐干旱胁迫和旱后复水处理,研究土壤逐渐干旱及复水对黑果腺肋花楸光合特性的影响。【结果】整个干旱胁迫期间,黑果腺肋花楸的净光合速率(Pn)、气孔导度(Gs)、胞间CO2 浓度(Ci)和蒸腾速率(Tr)均逐渐降低,而水分利用效率(WUE)随土壤干旱胁迫程度的加剧而上升;干旱胁迫下,黑果腺肋花楸的叶绿素总量显著降低,叶绿素 a/b 值显著增加,类胡萝卜素含量变化不明显,并维持较高的叶片相对含水量;CO2 补偿点升高,羧化效率明显减小;干旱 30 d,Pn、Gs、Ci 和 Tr 均降到最低值,均显著低于干旱处理前的水平,分别比干旱胁迫处理前下降了 85.4%、79.86%、31.98% 和 91.55%,仍具有一定生物活性,没有死亡;干旱复水后,叶片相对含水量能恢复至对照水平,Pn、Gs、Ci 和 Tr 均迅速升高,Gs、Ci、Tr 均未恢复到干旱处理 3 d 时的水平,但只比干旱处理 3 d 时降低 27.99%、14.15%、16.58%,Pn 比干旱处理 3 d 时升高 0.54%,通过表现出较强的恢复能力适应土壤干旱环境。【结论】干旱胁迫过程中,黑果腺肋花楸通过较高的 Pn、较低的 Tr 来提高 WUE,保持良好叶片水分状况来抵御干旱胁迫的伤害,胁迫去除后,叶片相对含水量和叶绿素含量均有所增高;各项光合参数值也有所回升,反映出黑果腺肋花楸在复水后具有较强的自我调节能力。

       

      Abstract: 【Objective】The study was to investigate the response of Aronia melanocarpa to soil drought stress. 【Method】 Taking two-year-old A. melanocarpa as the material, man-made simulation of drought stress, and postdrought water treatment were carried out through potted experiments, black fruit glints were studied. Two-year-old plants of A. melanocarpa were subjected to drought stress that simulated artificially. Gradual soil drought stress and subsequent rehydration treatments were carried out through pot experiment, and the effects of soil drought and rehydration on thephotosynthetic characteristics of A. melanocarpa were analyzed.【Result】During the whole process of drought stress, the net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr) of A. melanocarpa decreased gradually, however, the water use efficiency (WUE) increased with the aggravation of soil drought stress. Under drought stress, the total chlorophyll content decreased significantly, chlorophyll a/b value increased significantly, and carotenoid content did not change obviously, with higher leaf relative water content (RWC); the CO2 compensation point increased, and the carboxylation efficiency decreased significantly. After 30 days of drought, values of Pn, Gs, Ci and Tr all decreased to the lowest point, which were lower significantly than those before drought stress treatment with 85.4%, 79.86%, 31.98%, and 91.55%, respectively. Meanwhile, the A. Melanocarpa still had certain biological activity and no death occurred. After rehydration, the leaf RWC could be restored to the control level, and Pn, Gs, Ci and Tr all increased rapidly. However, Gs, Ci and Tr could not restore to the level of drought treatment for 3d, but only decreased by 27.99%, 14.15% and 16.58% compared with those under drought treatment for 3d while Pn was 0.54% higher than that of drought treatment 3d, showing strong resilience to adapt to soil drought.【Conclusion】In the course of drought stress, the A. melanocarpa increased its WUE with higher Pn and lower Tr, and maintained good leaf moisture condition to resist the damage caused by drought stress. After the removal of stress, both of leaf RWC and chlorophyll content increased and various photosynthetic parameters recovered. These findings reflected that A. melanocarpa had strong self-regulating capacity after rehydration.

       

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