干旱胁迫对侧金盏花生理特性的影响

Physiology of Adonis amurensis as Affected by Drought

【目的】研究侧金盏花植株在干旱及复水条件下的生理特性,为其引种栽培及应用提供理论依据。【方法】采用盆栽控水方式,研究不同程度干旱胁迫对其生理特性的影响。【结果】随胁迫程度加重,侧金盏花生物量、株高、叶片相对含水量、叶绿素(Chl)总量、可溶性蛋白含量降低,可溶性糖、丙二醛(MDA)含量和叶片相对电导率增加,脯氨酸(Pro)含量、过氧化物酶(POD)和超氧化物歧化酶(SOD)活性先上升后下降;净光合速率(P_(n))、气孔导度(G_(s))、蒸腾速率(T_(r))和胞间二氧化碳浓度(C_(i))均下降,最大荧光(F_(m))、光系统Ⅱ(PSⅡ)潜在活性、PSⅡ最大光化学量子产量、光化学猝灭系数(q_(p))、表观光合电子传递速率和PSⅡ实际光化学量子产量降低,初始荧光和非光化学猝灭逐渐增大;干旱前期(0~8 d)进行复水,土壤相对含水量不低于29.9%,各生理指标基本恢复至对照,干旱中期(8~12 d)复水后,各指标恢复速度较慢,干旱后期(12~16 d)复水后,各生理指标与对照相比差异显著。【结论】侧金盏花维持正常生长所能承受的持续干旱最长时间是8 d,其土壤相对含水量下限为29.9%;持续干旱8 d后,对侧金盏花造成不可逆伤害,因此对侧金盏花进行补水最晚不超过干旱发生的8 d。

【Objective】Physiological characteristics of Adonis amurensis in response to varying degrees of drought stress and subsequent rewatering were studied prior to the introduction for commercial cultivation and applications of the cultivar.【Method】Potting with controlled watering was applied to study the effects of varied drought stress and subsequent rewatering on the physiological characteristics of A.amurensis.【Result】The depleting water supply to the A.amurensis plants decreased the biomass,plant height,relative moisture content in leaf,total chlorophyll,and soluble protein,increased the contents of soluble sugar and malondialdehyde as well as the relative electrical conductivity of the leaves,and rose but followed by a decline on the contents of proline,peroxidase,and superoxide dismutase activities of the plants.Meanwhile,the indicators such as P_(n),G_(s),T_(r),and C_(i) decreased,F_(m),F_(v)/F_(o),F_(v)/F_(m),qP,ETR,andФ_(PSⅡ)gradually decreased,and F_(o) and NPQ gradually increased.Upon rewatering the soil to a moisture content no less than 29.9%in the early stage of drought treatment(0-8 d),the physiological indices fully returned to the control levels.However,the recovery slowed down when the rewatering took place in the mid stage(8-12 d),and the indices shifted significantly from control if the rewatering was implemented during 12-16 d after the draught stress began.【Conclusion】A.amurensis plants seemed to be capable of withstanding continuous water depletion up to 8 d and maintaining normal growth with a minimum 29.9%of soil relative moisture content.After the threshold points,prolonged drought stress with less than the minimum water requirement in the soil would irreversibly damage the plant physiology.Therefore,water supplement for A.amurensis should not exceed 8 days under drought condition.