• 研究论文 •

### 高寒草原优势种紫花针茅叶片解剖结构对青藏高原高寒干旱环境适应性分析

1. 中国科学院申扎高寒草原与湿地生态系统观测试验站, 山地表生过程与生态调控重点实验室, 中国科学院、水利部成都山地灾害与环境研究所, 成都, 610041
• 收稿日期:2020-09-25 接受日期:2021-01-14 出版日期:2021-03-20 发布日期:2021-05-17
• 通讯作者: 王小丹
• 作者简介:* (wxd@imde.ac.cn)
• 基金资助:
第二次青藏高原综合科学考察研究(SQ2019QZKK2004);国家重点研发计划(2016YFC0502002);国家自然科学基金(41401072)

### Analyzing leaf anatomical structure of dominant species Stipa purpurea adapting to alpine and drought environment at Qingzang Plateau

WU Jian-Bo, WANG Xiao-Dan()

1. Xainzha Alpine Steppe and Wetland Ecosystem Observation and Experiment Station, Key Laboratory of Mountain Environment Evolution and Regulation, Institute of Mountain Hazard and Environment, Chinese Academy of Sciences, Chengdu 610041, China
• Received:2020-09-25 Accepted:2021-01-14 Online:2021-03-20 Published:2021-05-17
• Contact: WANG Xiao-Dan
• Supported by:
Second Comprehensive Scientific Investigation of the Qinghai-Tibet Plateau(SQ2019QZKK2004);National Key R&D Program of China(2016YFC0502002);National Natural Science Foundation of China(41401072)

Abstract:

Aims The anatomical structure of plant leaves could be a direct reflection of the plant’s mechanism of response and adaptation to climate change. The distribution of alpine steppe has increased due to climatic warming over the Qingzang Plateau.Stipa purpurea is the dominant species of alpine steppe. However, few studies have been conducted on the adaptation mechanisms of alpine steppe plants. In this study, we analyzed the characteristics of leaf anatomical structure among different populations of S. purpurea and the relationship between these characteristics and climatic factors over the Qingzang Plateau. The ultimate aim was to identify the mechanism by which S. purpurea acclimatizes to alpine environments.
Methods Leaves of S. purpurea were collected from eight sites on the Qingzang Plateau and fixed using FAA fixative solution. Then, the leaves were paraffin wax sectioned and double-stained. Samples were then observed with a microscope and photographed with a digital camera. The area and thickness of leaf anatomical structure were measured with the soft (Image-pro plus 6.0).
Important findings Leaves of S. purpurea generally had thick cuticles, which were able to reduce water loss and radiation exposure. From the results of one-way analysis of variance, there were significant differences among the eight populations in collenchymatous cell thickness, vessel diameter, bundle catheter cavity area/bundle of the main vascular area, and vascular area/leaf cross-sectional area, which were beneficial characteristics for S. purpurea in adapting to the local environment. The characteristics of leaf anatomical structure were significantly correlated with environmental factors via Pearson’s analysis and cluster analysis. The results from principal component analysis and redundancy analysis showed that the anatomical structures in arid regions were mainly affected by annual evaporation, and those in semi-humid regions were mainly affected by the average precipitation humidity index and annual precipitation/annual evaporation during the growing season. In conclusion, to adapt to the alpine and arid environment,S. purpurea has reduced water loss by simultaneously increasing its collenchymatous cell thickness and water-conducting tissue area (vessel diameter, bundle catheter cavity area/bundle of main vascular area, and vascular bundle area/leaf cross-sectional area).