狭叶锦鸡儿叶片解剖结构对干旱胁迫下荒漠草原退化梯度的响应

摘要

According to the method of grassland survey-Height, coverage, abundance, Frequency and meteorological information of the Grassland, choosing 4 samples from 18 Etuokeqi desert grassland in Inner Mongolia, the grassland is divided into the comparison (CK), light degradation (LD), moderately degraded (MD) and heavy degraded (HD) from east to west depending on the drought and utilization degree of the grassland. The analysis of variance, correlation analysis and correspondence analysis were employed, in order to research theCaragana stenophylla Pojark leaf’s anatomical structure of each degradation degree, so as to study the ecological adaptability of C. stenophyllaPojark to drought stress gradient (Deterioration gradient) under natural conditions. The results showed that, (1) Anatomical structure ofCaragana stenophylla Pojark leaf looks like ‘V’ type inward bending. Different anatomical structures have different sensitivity to drought stress response, different plasticity was existed, anatomical structures with greater plasticity has a higher correlation with drought stress. (2) The width of the leaf was larger, while the rest of the structure dimensions were smaller under the condition of comparison (CK) and mild degradation (LD). However the thickness of the leaf (H), palisade tissue thickness of the axis distance (XBZ, SBZ), cell diameter of the upper and lower epidermal (SBX, XBX), cell wall thickness of the upper (SBB, XBB) and the thickness of the upper and lower stratum corneum (SBJ, XBJ) are all larger under the condition of moderately degraded (MD) and heavy degraded (HD). Under the long-term drought stress, the grassland has formed the different degrees of degradation, theC. stenophylla Pojark has become an anatomical structures that was adapt to the environment in order to adjust to the living environment. This high adaptability was the foundation and guarantee of its widely distributed.%根据草地“四度一量”和气象信息，从内蒙古鄂托克旗荒漠草原18个样点中选取4个，依草地干旱及利用程度由东向西划分为对照（CK）、轻度退化（LD）、中度退化（MD）和重度退化（HD）。利用方差分析、相关分析和对应分析法，对各退化程度上的狭叶锦鸡儿（Caragana stenophyllaPojark）叶片解剖结构进行了观察和研究，以探讨自然条件下，不同生境狭叶锦鸡儿对干旱胁迫梯度（退化梯度）的生态适应性。结果表明：（1）叶片解剖结构横切面为“V”型向内弯折，不同解剖结构对干旱胁迫响应敏感度不同，可塑性存在较大差异，可塑性较大解剖结构与干旱胁迫相关性较大；（2）对照和轻度退化条件下，叶片宽度（K）较大，其余结构尺寸均相对较小。中度和重度退化条件下，叶片厚度（H）、远近轴栅栏组织厚度（XBZ、SBZ）、上下表皮细胞直径（SBX、XBX）、上下表皮细胞壁厚度（SBB、XBB）和上下表皮角质层厚度（SBJ、XBJ）均较大。在长期干旱胁迫下，草地存在不同程度的退化，狭叶锦鸡儿为适应生境形成了与环境相适应的解剖结构，这种较强的适应性是其能够广泛分布的基础和保证。