红椿幼苗对干旱胁迫及复水生理响应的典型相关分析

Canonical correlation analysis on leaf physiological responses of Toona cilliate Roem.seedlings to drought stress and rewatering

【目的】探求干旱胁迫和复水条件下红椿盆栽幼苗叶片生理特性的整体相关性,为深入研究红椿的抗旱性奠定基础。【方法】在人工遮雨棚中对2年生红椿盆栽幼苗进行干旱胁迫及复水试验,测定叶片相对含水量、相对电导率、叶绿素含量、SOD活性、POD活性、MDA含量、游离脯氨酸含量及可溶性蛋白含量8个叶片生理指标,并运用典型相关法对未干旱(干旱胁迫前)、干旱胁迫及复水条件下3组指标两两之间的整体相关性进行分析。【结果】(1)干旱胁迫前与干旱胁迫条件下,红椿盆栽幼苗叶片生理特性之间存在显著相关关系,干旱胁迫前及干旱胁迫下红椿幼苗生理响应典型相关分析的第1对典型变量(U1,V1)的相关系数达到0.996 5,叶片相对电导率可以反映干旱胁迫前的生理特性,叶绿素含量可以反映干旱胁迫的生理特性。(2)干旱胁迫与复水后红椿盆栽幼苗叶片生理特性有显著相关关系,干旱胁迫及复水条件下红椿幼苗生理响应典型相关分析的第1对典型变量(W1,Z1)的相关系数达到0.998 3,反映干旱胁迫和复水后生理特性的典型变量均主要由叶片相对电导率决定。(3)干旱胁迫下叶绿素含量与复水时的POD活性和MDA含量均呈显著正相关关系,说明干旱胁迫下红椿幼苗光合作用的保持能力强,则复水时表现出来的抗氧化酶活性也高。(4)干旱胁迫下可溶性蛋白含量与复水后的POD活性呈极显著正相关关系,相关系数达到0.803,说明复水时红椿幼苗植株叶片生理特性的恢复状况与干旱胁迫时受创的严重程度密切相关。(5)干旱迫胁前与复水后叶片生理指标的相关性表明,复水后红椿幼苗植株的耗水量、抗旱性与正常供水时植株的抗旱潜力直接相关。【结论】干旱胁迫伤害程度不重,则对复水后红椿幼苗植株体内叶绿素含量和POD活性的恢复具有积极作用。适当干旱能促进植株抗逆性的提高,过度缺水则会对植株造成伤害,且修复慢,符合生物节水原理。

【Objective】The study discovered the correlation of leaf physiological characteristics of Too-na cilliate Roem.potted seedlings among drought stress and rewatering to build knowledge foundation for investigating drought tolerance of Toona cilliate Roem.【Method】The drought stress and rewatering experiment was conducted in artificial-rain-shelter with 2years old Toona cilliate Roem.potted seedlings.Eight leaf physiological indicators including leaf relative water content,leaf relative conductivity,chlorophyll content,SOD activity,POD activity,MDA content,free proline content and soluble protein content were determined.Canonical correlation was adopted to analyze the overall correlation of leaf physiological characteristics between control,drought stress and rewatering cases.【Result】（1）There was significant correlation in leaf physiological characteristics of Toona cilliate Roem.potted seedlings between control and drought stress cases.The first coefficient of canonical correlation analysis was 0.996 5,Leaf relative conductivity and chlorophyll content mainly reflected the leaf physiological characteristics before and after drought stress,respectively.（2）There was significant correlation in leaf physiological characteristics of Toona cilliate Roem.potted seedlings between drought stress and rewatering cases.The first coefficient of canonical correlation analysis was 0.998 3.Leaf relative conductivity mainly reflected leaf physiological characteristics both in drought stress and rewatering cases.（3）There was significant positive correlation between chlorophyll content under drought stress and POD activity and MDA content in rewatering case,indicating that higher photosynthetic capacity under drought stress caused higher antioxidant enzyme activity in rewatering.（4）Soluble protein content under drought stress extremely correlated with POD activity in rewatering with the correlation coefficient of 0.803,indicating that the damage severity under drought stress closely influenced the reparation of leaf physiological characteristics in rewatering.（5）Water consumption and drought tolerance of Toona cilliate Roem.after rewatering were directly related to droughtresistant potential in normal watering case.【Conclusion】Slight drought damage could positively promote the recovery of chlorophyll content and POD activity of Toona cilliate Roem.seedlings after rewatering.Thus,proper water deficit could improve the drought resistance ability of plants,while excessive water shortage could harm the plants and the reparation would last for a long period.