文献类型： 外文期刊

作者： Wang, Xue-mei ¹ ; Zhao, Li ³ ; Yan, Bang-guo ¹ ; Shi, Liang-tao ⁴ ; Liu, Gang-cai ¹ ; He, Yu-xiao ⁵ ;

作者机构： 1.Chinese Acad Sci & Minist Water Resources, Key Lab Mt Surface Proc & Ecol Regulat, Inst Mt Hazards & Environm, Chengdu 610041, Peoples R China

2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China

3.Southwest Univ Sci & Technol, Coll Environm & Resource Sci, Mianyang 621010, Peoples R China

4.Yunnan Acad Agr Sci, Inst Trop Ecoagr Sci, Yuanmou 651300, Yunnan Province, Peoples R China

5.Henan Polytech Univ, Inst Resources & Environm, Jiaozuo 454000, Henan, Peoples R China

关键词： Heteropogon contortus;Drought stress;Biomass allocation;Leaf water potential;Relative water content;Chlorophyll fluorescence

期刊名称：BOTANICAL STUDIES （ 影响因子：2.787； 五年影响因子：2.871 ）

ISSN： 1999-3110

年卷期： 2016 年 57 卷

页码：

收录情况： SCI

摘要： Background: Heteropogon contortus is a valuable pasture species that is widely used for vegetation restoration in dry-hot valleys of China. However, to date, its morphological and physiological responses to drought, and the underlying mechanisms are not well understood. This study was aimed to investigate the morphological and physiological changes of H. contortus under drought stress during the dry-hot season. Heteropogon contortus was planted in pots and subjected to four levels of soil water treatments: above 85 % (control), 70-75 % (light stress), 55-60 % (moderate stress) or 35-40 % (severe stress) of field capacity. Results: Within the total stress period (0-29 days), H. contortus grew rapidly in the light stress, whereas severe stress had a negative impact on growth. Aboveground biomass decreased together with increasing drought stress, whereas root biomass increased. Consequently, the root/shoot ratio of the severe stress treatment increased by 80 % compared to that of the control treatment. The ratio of bound water/free water (BW/FW) was the most sensitive parameter to drought and showed a value under severe stress that was 152.83 % more than that in the control treatment. Although leaf water potential (LWP) and leaf relative water content (RWC) decreased with progressive water stress, H. contortus managed to maintain a relatively high RWC (nearly 70 %) in the severe stress condition. We also detected a significant reduction (below 0.6) in the ratio of variable fluorescence/maximum fluorescence (Fv/Fm) in the severe stress treatment. Conclusions: Our results show that H. contortus adapts to drought mainly by avoidance mechanisms, and its morphological and physiological characteristics are inhibited under severe stress, but can recover at a certain time after re-watering. These findings might help limited water resources to be fully used for vegetation management in the studied region.