胡杨异形叶枝叶大小关系对干旱胁迫的响应  

Response of Twig-Leaf Size Relationships Populus euphratica with Heteromorphic Leaves to Drought Stress

作　　者：孔翠翠 伊力哈穆江·艾尼弯 马利刚 隆彦昕[1,2] 王雅芸 杨晓东 Kong Cuicui;Elhamjan Anwar;Ma Ligang;Long Yanxin;Wang Yayun;Yang Xiaodong(Key Laboratory of Oasis Ecology,Urumqi 830046;College of Resources and Environment Science,Xinjiang University,Urumqi 830046;Department of Geography&Spatial Information Technology,Ningbo University,Ningbo 315211)

机构地区：[1]绿洲生态教育部重点实验室,乌鲁木齐830046 [2]新疆大学资源与环境科学学院,乌鲁木齐830046 [3]宁波大学地理与空间信息技术系,宁波315211

出　　处：《林业科学》2022年第12期42-51,共10页Scientia Silvae Sinicae

基　　金：国家自然科学基金项目(31860111,41871031,41661079)。

摘　　要：【目的】分析胡杨在干旱胁迫下胡杨异形叶枝叶变化,为阐明异形叶形成机制以及对胡杨个体的保育提供参考。【方法】以新疆艾比湖湿地自然保护区内胡杨3种异形叶(卵形叶、近卵形叶和披针形叶)为研究对象,测定18棵胡杨上当年生枝条的横截面积和其上着生叶片的面积、叶片塑型特征以及其余7个水力学性状和叶片解剖性状,并比较它们在不同异形叶之间的差异;采用标准主轴回归比较胡杨异形叶枝叶大小关系的不同,对胡杨枝叶大小关系与水力学性状和叶片解剖性状进行复相关分析。【结果】1)小枝的横截面积和总叶面积呈显著等速生长关系,两者的回归斜率在0.65~1.06之间,与1相比无显著性差异(P>0.05)。2)标准主轴回归结果表明,在3种异形叶间,叶片总面积对枝横截面积的回归存在共同斜率(a=0.83)。共同斜率条件下,回归截距(b)在3种异形叶间存在差异:卵形叶(1.41)>近卵形叶(1.35)>披针形叶(1.25)。3)叶长、叶宽、叶长宽比、最大蒸腾速率、胡伯尔值、气孔大小、气孔密度和栅栏组织厚度在3种异形叶之间存在显著差异(P<0.05),相反,黎明前叶水势和枝比导率没有显著差异(P>0.05)。4)枝叶大小关系与胡伯尔值、气孔大小、气孔密度、栅栏厚度、最大蒸腾速率和黎明前叶水势呈显著复相关(P<0.05)。【结论】胡杨当年生小枝与其上着生总叶面积在营养分配上比例相当,是一种维持水分运输和机械支撑之间平衡的适应策略。在小枝横截面积相同的条件下,其上着生卵形叶的总面积高于近卵形叶,更高于披针形叶。胡杨枝叶大小关系在异形叶之间的变化有利于改善胡杨的水力学特性,从而提高水分运输能力,降低干旱胁迫。【Objective】The purpose of this study is to analyze whether changes in the twig-leaf size relationships could reduce the drought stress of Populus euphratica with heteromorphic leaves,which could provide reference for clarifying the formation mechanism of heteromorphic leaves and the conservation of P.euphratica individuals.【Method】Three main heteromorphic leaves,i.e.,ovate,nearly ovate and lanceolate leaf,of P.euphratica in the Ebinur Lake Wetland National Nature Reserve in the Xinjiang,China,were taken as the research object.The cross-sectional area of twigs,the total leaf area on the twigs,the hydraulic and anatomical traits were determined experimentally in 18 P.euphratica individuals,and then the standardized major axis regression(SMA)was used to compare the difference in the relationship of size between twig and leaf among three heteromorphic leaves.Multi-correlation analysis was conducted to test the effects of the twig-leaf size relationships on the hydraulic and anatomical traits.【Result】1)There was a significant isometric growth relationship between the cross-sectional area of twigs and the total leaf area.The regression slope of twig-leaf size relationships ranged from 0.65 to 1.06;which had no significant difference compared with 1(P>0.05).2)The SMA results showed that there was a common slope(a=0.83)for the regression of the total leaf area to twig cross-sectional area among heteromorphic leaves.Under the condition of common slope,the intercept(b)differed among the three heteromorphic leaves:ovate(1.41)>nearly ovate(1.35)>lanceolate leaf(1.25).3)There were significant differences in leaf length,leaf width,leaf length-width ratio,maximum transpiration rate,Huber value,stomatal size and density,and palisade tissue thickness among the three heteromorphic leaves(P<0.05),while pre-dawn leaf water potential and specific conductivity of twigs were not different(P>0.05).4)The twig-leaf size relationship was significantly correlated with Huber value,stomatal size and density,palisade tissue thickne

关 键 词：异形叶 Corner法则 异速生长 枝叶大小关系 水力运输 资源分配策略 

分 类 号：S718.43[农业科学—林学]