Arid Zone Research ›› 2022, Vol. 39 ›› Issue (3): 893-899.doi: 10.13866/j.azr.2022.03.22

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Response of drought on water and nitrogen utilization and carbohydrate distribution of Populus × euramericana ‘Biyu’ cuttings

SHANG Jiazhou1(),ZHAO Yuqi1(),WANG Weifeng1(),GAO Tianhui1,ZONG Yuzheng2   

  1. 1. College of Forestry, Shanxi Agricultural University, Jinzhong 030801, Shanxi, China
    2. College of Agronomy, Shanxi Agricultural University, Jinzhong 030801, Shanxi, China
  • Received:2021-11-12 Revised:2022-02-21 Online:2022-05-15 Published:2022-05-30
  • Contact: Yuqi ZHAO,Weifeng WANG E-mail:shangjz1111@163.com;wangwf2020@163.com

Abstract:

The ecophysiological response of poplar to soil drought and drought resistance strategies among species remained unclear. In this study, Populus×euramericana ‘Biyu’ cuttings grown in pots were used as materials. Changes of leaf gas exchanges, water and nitrogen use traits, growth, and carbohydrate allocation among organs under 2-year drought were investigated. Results showed that the leaves of 1-year-old poplar cuttings became smaller but thicker under drought with stable stomatal conductance, and transpiration rate. The net photosynthesis rate decreased by non-stomatal inhibition, and the transient water and nitrogen use efficiency significantly decreased. In the second year, the leaves became even smaller and thicker with a higher carbon and nitrogen ratio. However, leaf nitrogen contents remained unchanged, which could improve leaf drought resistance. The net photosynthesis rate increased slightly, and transient water and nitrogen use efficiency remained stable. Moreover, moderate drought significantly increased whole-plant nitrogen use efficiency. Under a 2-year drought treatment, the growth significantly decreased. More biomass and non-structural carbohydrates allocated into the stem but not in the root system, and the root and shoot ratio became smaller, which are detrimental to the water and nitrogen uptake in the root and whole-plant drought resistance. Therefore, P.× euramericana ‘Biyu’cuttings can reduce water consumption in smaller but thicker leaves under drought, with high leaf nitrogen content, but this response could reduce the leaf area used for photosynthesis, resulting in decreased growth and smaller roots. These results indicated that P.×euramericana ‘Biyu’ has low drought resistance, which is not suitable for large-scale afforestation in arid and semi-arid areas.

Key words: poplar, drought, leaf gas exchanges, water and nitrogen use efficiency, carbohydrate distribution