峨眉山不同海拔高度3种竹叶片结构特征变化研究

Changes in Leaf Structural Characteristics of Three Bamboo Species at Different Altitudes in Mount Emei

为研究竹叶片结构适应环境的变化,本文采用统计分析和电镜扫描技术,对峨眉山不同海拔高度的慈竹、八月竹和短锥玉山竹叶片的表型特征和解剖结构进行比较。结果表明:(1)3种竹叶片的叶长、叶宽、长宽比、叶面积及比叶面积在不同海拔高度显著差异,三种竹叶长、叶宽、叶面积、比叶面积均与海拔呈显著的负相关关系。(2)3种竹均为等面叶,表皮上有角质层,且上表皮厚度明显大于下表皮厚度,乳突紧密排列,其中八月竹及短锥玉山竹的气孔器被乳突掩盖;相邻维管束之间有许多大小不一而明显的气腔结构,种间存在差异。(3)3种竹的维管束长宽与海拔呈极显著负相关,叶片厚度与海拔呈极显著正相关,慈竹及八月竹的下表皮厚度与海拔的相关性不显著;八月竹叶片结构多项指标的可塑性指数均优于慈竹和短锥玉山竹,具有较强的结构可塑性,慈竹主要表型特征随海拔梯度变化极显著变化,表现出较强的表型特征可塑性。本研究分析了不同竹种叶片对分布范围内海拔梯度垂直变化的形态变化特征,对研究竹类的生态适应性和分布具有重要的参考价值。

In order to study the response of bamboo leaf structure to the environment, the statistical analysis and electron microscopy scanning techniques （SEM） were used to compare the phenotypie characteristics and anatomical structures of the leaves of three bamboo species, Neosinocalamus affinis, Chimonobambusa szechuanens and Yushania brevipaniculata, at different altitudes in Mountain Emei. The results showed that （1） the leaf length, leaf width, ratio of leaf length to width, leaf area and specific leaf area of the three bamboo species were all different and there was a significant negative correlation with elevation. （2） All three kinds of bamboos had isobilateral leaves, the epidermis covered with cuticles, the upper epidermis thickness was significantly greater than the lower epidermis; the papillae was closely arranged, and the stomata apparatus was covered by mastoid in C. szechuanens and Y. brevipaniculata. There found many air cavity structures with different sizes between the tube bundles, and therewere differences between species. （3） The length and width of the vascular bundles of three species were negatively correlated with elevation, while the leaf thickness was positively correlated with elevation. There was no significant correlation between the thickness of the lower epidermis and the altitude in N. affinis and C. szechuanens. Most indexes of plasticity of C. szechuanens leaf structure were better than that of N. affinis and Y. brevipaniculata. The main phenotypic characteristics of N. affinis changed significantly with the elevation gradient, showing a strong phenotypic plasticity. This paper presented the variations in morphological characteristics of different bamboo species with elevation gradients. This may provide important reference for the ecological adaptability and distribution of bamboo species.