宇璐沙棘与深秋红沙棘对干旱胁迫的生长与生理响应

Growth and Physiological Responses of Hippophae rhamnoides“Yulu”and H.rhamnoides“Shenqiuhong”to Drought Stress

为明确宇璐沙棘和深秋红沙棘的生长、光合特性和生理生化物质对干旱胁迫的响应特征,以1年生宇璐沙棘与深秋红沙棘为试验材料,采用盆栽方法,设置持续120 d 3个水分梯度的处理,测试分析2个沙棘品种的生长性状,并结合2个沙棘品种在干旱胁迫期间光合特征和生理生化物质含量的变化,利用隶属函数法综合评价其抗旱能力。结果表明,干旱胁迫下2个沙棘品种的株高、地径和根长的生长均受到抑制,净光合速率(P_n)、蒸腾速率(T_(r))、胞间CO_(2)浓度(C_(i))、气孔导度(G_(s))、羧化效率(CE)呈减小趋势,气孔限制值(L_(s))和叶片瞬时水分利用效率(WUEi)呈增加趋势。与深秋红沙棘相比,宇璐沙棘根长更长,气孔调节机制更灵敏,具有较高的叶片瞬时水分利用效率和根系生理抗性来抵御干旱胁迫。与宇璐沙棘相比,深秋红沙棘的气孔导度、胞间CO_(2)浓度和蒸腾速率更高,具有较高的光合能力和叶片生理抗性,进而增强根系吸水能力,以抵御干旱胁迫。隶属函数评价结果表明,宇璐沙棘的叶片瞬时水分利用效率高于深秋红沙棘,宇璐沙棘的抗旱策略更为安全,抗旱性能更强。

In order to clarify the response of growth,photosynthetic characteristics and physiological and biochemical substances of two sea-buckthorn varieties:Hippophae rhamnoides“Yulu”and H.rhamnoides“Shenqiuhong”to drought stress,one-year-old seedlings of the two varieties were selected as experimental materials.The pot-culture method was used to set up three water gradient treatments for 120 days.The growth traits of the two varieties were measured and analyzed.Combined with the changes of photosynthetic characteristics and physiological and biochemical substance contents of the two varieties during drought stress,the drought resistance of the two varieties was comprehensively evaluated by membership function values.The results showed that the growth of plant height,ground diameter and root length of the two varieties were inhibited under drought stress.The net photosynthetic rate(P_(n)),transpiration rate(T_(r)),intercellular CO_(2)concentration(C_(i)),stomatal conductance(Gs)and carboxylation efficiency(CE)showed decreasing trends,while the stomatal limitation value(L_(s))and instantaneous water use efficiency(WUEi)showed increasing trends.Compared with variety“Shenqiuhong”,“Yulu”had longer root length,more sensitive stomatal regulation mechanism,higher leaf WUEi and strong root physiological resistance to drought stress.Compared with“Yulu”,G_(s),C_(i)and T_(r)of“Shenqiuhong”were higher,with higher photosynthetic capacity and leaf physiological resistance,thereby enhancing root water absorption to resist drought stress.The results of membership function values showed that the WUEi of“Yulu”was higher than that of“Shenqiuhong”,and the drought resistance strategy of“Yulu”was safer and stronger.