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植物光合器官形态解剖结构对叶片水力导度(Kleaf)有一定指示作用。对塔里木河下游4个地下水埋深下胡杨(Populus euphratica)叶片形态解剖结构和叶片最大水力导度(Kleaf-max)分析结果显示:(1)胡杨叶片具有明显的旱生结构特点。叶片较厚,等叶面,复表皮,栅栏组织发达,排列紧密,叶肉细胞中含有两种结晶体——棱晶和簇晶,叶脉密集,气孔下陷。(2)随着地下水埋深的增大,胡杨叶片厚度(LT)、表层厚度(ET)、栅栏组织厚度(PT)、栅海比(栅栏组织厚度/海绵组织厚度,PT/ST)、叶脉密度(LVD)、主脉导管直径(MVD)、气孔密度(SD)、Kleaf-max都出现显著增加趋势,气孔面积(SA)则呈显著减小趋势,表明胡杨叶片在受到水分胁迫下通过改变形态解剖结构和水分传输效率来适应干旱。(3)胡杨叶片Kleaf-max值与LT、ET、PT、PT/ST、LVD、MVD、SD有着极显著的正相关关系(P<0.01),与SA存在极显著的负相关关系(P<0.01),这表明胡杨叶片具有的形态解剖结构特征,是其叶片水力传导能力变化的基础。
The morphological and anatomical structure of photosynthetic organs of plants has some indication on the leaf water conductivity (Kleaf). The results of morphological anatomy and leaf maximum hydraulic conductivity (Kleaf-max) analysis of Populus euphratica under four groundwater depths in the lower reaches of the Tarim River show that: (1) The Populus euphratica leaves have obvious structural characteristics of drought. Leaf thick, isoflavone, complex epidermis, well-organized palisade, arranged closely, mesophyll cells contain two kinds of crystals - prisms and clusters, dense veins, stomatal sag. (2) With the increase of groundwater depth, leaf thickness (LT), epidermal thickness (ET), palisade tissue thickness (PT), net ratio of scallop (palisade tissue thickness / spongy tissue thickness, PT / ST) LVD, MVD, SD and Kleaf-max all increased significantly while the stomatal area (SA) decreased significantly, which indicated that the leaf area of Populus euphratica was significantly decreased under water stress Morphological anatomy and water transfer efficiency to adapt to drought. (3) There was a significant positive correlation between Kleaf-max value of Populus euphratica leaves and LT, ET, PT, PT / ST, LVD, MVD and SD (P < 0.01). This indicates that the morphological and anatomical characteristics of the leaves of Populus euphratica are the basis of the changes of leaf hydraulic conductivity.