新疆沙冬青(Ammopiptanthus nanus)和蒙古沙冬青(A. monglicus)叶片解剖特征及抗旱性

Leaf Eco-anatomical Characteristics of Ammopiptanthus nanus and Ammopiptanthus monglicus

以新疆沙冬青(Ammopiptanthus nanus)幼苗叶片、蒙古沙冬青(A.monglicus)幼苗及成年叶片为研究对象,采用石蜡切片法将叶片解剖并固定,再用光学显微观察法对其抗旱性结构分析比较,旨在探讨沙冬青属植物叶片在干旱环境的生态适应机制。采用方差分析法对各指标的差异性进行比较分析,通过Pearson's相关系数法分析各指标间相关关系。结果表明:(1)新疆沙冬青与蒙古沙冬青幼苗叶片厚度无显著差异;新疆沙冬青幼苗叶片的角质层厚度及上、下表皮厚度及栅栏组织厚度均显著大于蒙古沙冬青幼苗;新疆沙冬青幼苗叶片的海绵组织厚度和主脉直径均显著小于蒙古沙冬青。蒙古沙冬青成年植株叶片厚度、角质层厚度、栅栏组织厚度及主脉直径均显著大于幼苗,上、下表皮厚度及海绵组织厚度均小于幼苗。(2)沙冬青属植物叶片栅栏组织厚度与叶片厚度显著正相关;下表皮厚度、角质层厚度、海绵组织厚度与叶片厚度相关性不显著。为了更好适应分布区环境,新疆沙冬青叶片比蒙古沙冬青具有更强的抗旱性,蒙古沙冬青成年植株叶片的抗旱性优于幼苗。沙冬青属植物叶片的加厚主要通过栅栏组织的加厚实现。

The seedlings leaves of Ammopiptanthus nanus and seedlings and adult leaves of Ammopip- tanthus mongolicus were studied by paraffin sectioning, and their structures were analyzed by optical mi- croscopy. The purpose of this study is to explore the ecological adaptation mechanism of the leaves of the plant of the genus Ammopiptanthus in the arid environment. The variance analysis method was used to compare the differences of the indexes, and the correlation between the indexes was analyzed by the Pearson ＂s correlation coefficient method. The results showed that： （1） Seedling leaf thicknesses were no significant difference between A. nanus and A. mongolicus ; Thickness of seedlings leaf cuticle, upper and lower ep- idermis and palisade tissue of A. nanus were significantly higher than those of A. mongolicus ; sponge tis- sue thickness and the diameter of the main vein of A. nanus seedlings were significantly less than A. mon- golicus. The leaf thickness, cuticle thickness, palisade tissue thickness and main vein diameter of adults A. mongolicus were significantly higher than those of seedlings. The thickness of the upper and lower epider- mis and the thickness of sponge tissue were all smaller than those of seedlings. （2） the thickness of palisade tissue was positively correlated with leaf thickness; the thickness of lower epidermis, the thickness of stra- tum corneum, and the thickness of sponge tissue were not significantly correlated with leaf thickness. In or- der to better adapt to the environment, the drought resistance of leaf of A. nanus is stronger than A. mongolicus, and drought resistance of adult A. mongolicus is better than that of seedling leaves. The thickening of the leaves of the genus Ammopiptanthus is mainly realized by the thickening of the palisade tissue.