摘要
植物叶片对环境变化十分敏感,能反映植物适应环境所形成的生存策略。为揭示高寒植物叶片性状对海拔高度变化的响应,对位于青藏高原东北部的冷龙岭3400—4200 m之间5个不同海拔高度的矮火绒草(Leontopodium nanum)叶片进行取样,采用常规石蜡制片技术和显微观察方法测定叶片外部形态、表皮气孔特征和解剖结构,探讨其叶片性状随海拔的变化,结果表明:(1)随海拔高度升高,叶面积呈减小的趋势,而比叶重和叶干物质含量增加;(2)叶片下表皮气孔密度随海拔升高呈先增加后下降的趋势,且气孔密度、气孔器面积、长度、宽度和潜在气孔导度指数等气孔特征之间存在显著相关性;(3)叶厚、栅栏组织和海绵组织厚度随海拔升高呈显著增厚的趋势;(4)叶片解剖结构可塑性和相关性分析显示,上、下角质层厚度的可塑性指数最大,而部分解剖结构指标间存在极显著的相关性。研究表明,矮火绒草为适应沿海拔上升温度降低的环境,主要采取叶片变小、变厚的对策,使植物趋于保温、保水和抗机械损伤的方向发展,并将资源最大化地投入到自身生长发育中。
In the context of global warming,how plants adapt to changes in environmental factors has become one of the hot topics in ecological research in past decade.Leaves,as the organs with the largest surface area exposed to the sun and air,are the most important place for the exchange of energy and mass between plants and the atmosphere,and are also considered to be the link between plants and the environment.Leaves are very sensitive to environmental changes,and usually show differences in external morphology,epidermal characteristics and anatomical structures with changes in the environment(temperature,solar radiation etc),which can reflect the survival strategies formed by plants adapting to environmental changes.The Qinghai-Tibetan Plateau is one of the most sensitive areas responding to climate change in the world because of its unique topography,and the change of altitude gradient will correspond to the variations of various environmental factors,especially the temperature.Therefore,it has become an ideal place to study the adaptation of leaf traits to environment.In order to examine the responses of leaf traits of alpine plants to altitude changes,the paraffin section method and microscopic techniques were used to study the external morphology,epidermal and stomatal characteristics and anatomical structures of the leaves of Leontopodium nanum from five different altitudes from 3400 m to 4200 m in Lenglong Ling(Ridge),northeast of the Qinghai-Tibetan Plateau,and the changes in leaf traits with altitude were investigated.The results showed that:(1)when the altitude increased,the leave of Leontopodium nanum tended to be reducing in size,while the specific leaf weight and leaf dry matter content showed an increasing trend;(2)the stomatal density of lower epidermis was first up and then down with the increasing altitude,and there were significant correlations among stomatal characteristics such as stomatal density,stomatal apparatus area,stomatal length,stomatal width and potential conductance index;(3)leaf thickness,palisade and spongy tissue thickness increased significantly with increasing altitude;(4)leaf anatomical plasticity showed that the upper and lower cuticle thickness had the largest plasticity index,and there were significant correlations among some anatomical traits according to the correlation analysis.The results of this study suggested that the Leontopodium nanum had chosen the strategy by producing smaller and thicker leaves in order to adapt to decreasing ambient temperature with the increasing altitude,which can help itself to resist cold environment,improve water use efficiency,and maximize access to resources in plant growth and development,and then to prolong its life span and benefit its survival in the cold alpine environment.
作者
郑梦娜
贾傲
陈之光
廣田充
唐艳鸿
杜明远
古松
ZHENG Mengna;JIA Ao;CHEN Zhiguang;HIROTA Mitsuru;TANG Yanhong;DU Mingyuan;GU Song(College of Life Sciences,Nankai University,Tianjin 300071,China;University of Tsukuba,Tsukuba 3050006,Japan;College of Urban and Environmental Sciences,Peking University,Beijing 100871,China;Japan Agricultural Environmental Technology Research Institute,Tsukuba 3050006,Japan)
出处
《生态学报》
CAS
CSCD
北大核心
2022年第24期10305-10316,共12页
Acta Ecologica Sinica
基金
第二次青藏高原综合科学考察研究项目(2019QZKK0106)
关键词
矮火绒草
海拔
叶片外部形态
气孔特征
解剖结构
Leontopodium nanum
altitude
leaf external morphology
stomatal characteristics
anatomical structures
作者简介
通讯作者:古松.E-mail:songgu@nankai.edu.cn
