色季拉山2种风毛菊植物叶片结构特征及生态适应性初步研究

Preliminary Study on Leaf Structure Changes and Ecological Adaptability of Two Species of Saussurea at Different Altitude on the Sejila Mountain

为揭示植物随海拔高度变化的响应规律,从而探讨分析植物对高寒高海拔环境适应性,以期为青藏高原地区草甸生态系统的物种保护提供科学支撑以及为高原植物功能生态学的研究提供参考依据。本研究区域选择西藏林芝色季拉山海拔4400~4600 m的高山高海拔草甸,选择2种在此海拔带均有分布生长的植物狮牙状风毛菊(Saussurea leontodontoides)与硬叶风毛菊(S.ciliaris),分别采用方差分析、相关性分析等方法从外部形态和内部解剖结构对2种植物进行分析。结果表明:(1)2种植物随着海拔高度的升高均有明显变化规律外(叶脉、叶片、上角质层、上下表皮)的厚度、栅栏系数均随海拔升高而增加;(2)2种植物的外部形态,其中株高、叶长、叶柄长三个表型性状在随海拔梯度的变化表现出了一致性,两种植物的形状都有不同的显著相关性表现,其中株高与叶长、叶柄长都呈现显著和极显著相关性,种质资源在叶和茎部特征上存在较高的形态多样性,多样性指数分别在0~2.002、0~1.992之间,变异系数在0%~56.22%、0%~46.66%之间,具有较大的变异系数,且质量性状多样性指数低于数量性状,变异系数表现的趋势则相反。得出结论:2种植物具有较高的丰富度和均匀度,遗传多样性广泛,并且不同海拔上,具有不同的适应策略;2种植物分析解剖学与外观形态多数指标表明2种植物呈现出明显的协同进化,并且采取不同的响应机制来适应海拔高度变化后的低温、缺氧以及强辐射的恶劣环境。

To reveal the response rules of plants to changes in altitude,and thereby to explore and analyze the adaptability of plants to cold and high-altitude environments,this paper will provide scientific support for species protection of the meadow ecosystem in the Qinghai-Tibet Plateau and provide reference basis for the study of plant functional ecology on the plateau.In this study area,the alpine and high-altitude meadows at an altitude of 4400 to 4600 meters in the Sejila Mountain of Nyingchi,Tibet were selected,together with two plants,Saussurea leontodontoides and S.ciliaris,which are distributed and grow at this altitude.In this study,the two plants were analyzed in terms of external morphology and internal anatomical structure using ANOVA and correlation analysis,respectively.The findings of the study indicated that the thickness of the outer structures of the leaf,such as leaf veins,blade,upper cuticle,and upper and lower epidermis,as well as the fenestration coefficient of both plant species,exhibited significant changes with increasing altitude.Additionally,the external morphology of the two species,particularly their plant height,leaf length,and petiole length,displayed consistency with the altitude gradient.Furthermore,the shapes of the two species were significantly correlated with plant height,exhibiting a significant and highly significant correlation with both leaf length and petiole length.The germplasm resources of the two species exhibited high morphological diversity in leaf and stem characteristics,as evidenced by diversity indices ranging from 0 to 2.002 and 0 to 1.992,respectively,and coefficients of variation ranging from 0%to 56.22%and 0%to 46.66%,with large coefficients of variation.The diversity indices of quantitative traits were higher than those of qualitative traits,and the coefficients of variation showed an opposite trend.In conclusion,the results of this study suggest that the two plants have high abundance and evenness,extensive genetic diversity,and different adaptation strategies at different altitudes,and most indicators of anatomy and appearance of the two plants indicated that the two plants exhibited significant coevolution and adopted different response mechanisms to adapting to the harsh environment of low temperature,hypoxia,and strong radiation following changes in altitude.