Chin J Plant Ecol ›› 2018, Vol. 42 ›› Issue (7): 741-751.DOI: 10.17521/cjpe.2018.0097

• Research Articles • Previous Articles     Next Articles

Patterns of variations in leaf turgor pressure and responses to environmental factors in Populus tomentosa

LI Dou-Dou1,*, XI Ben-Ye1,*, WANG Fei2, JIA Su-Ping3, ZHAO Hong-Lin4, HE Yue-Lin1, LIU Yang1, JIA Li-Ming1,**()   

  1. 1 Ministry of Education Key Laboratory of Silviculture and Conservation, Beijing Forestry University, Beijing 100083, China
    2 Liaocheng Forestry Bureau, Liaocheng, Shandong 252002, China
    3 Forestry Workstation of Daxing District in Beijing, Beijing 102600, China
    4 Forestry Protection Station of Daxing District in Beijing, Beijing 102600, China
  • Online:2018-07-20 Published:2018-06-11
  • Contact: Dou-Dou LI,Ben-Ye XI,Li-Ming JIA
  • Supported by:
    Supported by the Key Technologies R&D Program of China(2015BAD09B02);the National Natural Science Foundation of China(31400532);the National Natural Science Foundation of China(31670625);the National Key Research and Development Program of China(2016YFD0600403)


Aims In this study, the patterns of variations in leaf turgor pressure and responses to environmental factors were investigated in Populus tomentosa, in order to provide a theoretical basis for guiding irrigation using leaf turgor pressure as a water stress indicator.

Methods The study was conducted in a two-year-old Populus tomentosaplantation under surface drip irrigation. Leaf patch clamp pressure (Pp) was continuously monitored in treatments of full irrigation (FI) and control (CK). Soil temperature (Ts), soil water potential (Ψs), sap flow velocity (VSF) and meteorological factors were monitored simultaneously. The patterns of variations in leaf turgor pressure and relationships between Pp and environmental factors of P. tomentosa under different water treatments were analyzed.

Important findings The Pp values exhibited a clear pattern of “daytime high and nighttime low” with varying weather conditions, and the width of peak signals in Pp was greatest in sunny days. The positive relationships between normalized leaf patch pressure (ΔPp) and VSF fitted a polynomial function under different weather conditions, with R2 values ranked in the order of sunny days (0.87) > cloudy days (0.72) > rainy days (0.31). Photosynthetically active radiation (PAR), air temperature (Ta), relative air humidity (RH), and vapor pressure deficiency (VPD) were predominant environmental factors affecting Pp, especially PAR. Hysteresis was found between ΔPp and different environmental factors, and the size of the hysteresis loop differed between the two irrigation treatments. There were significant differences in the shapes of Pp curves between the irrigation treatments. In conclusion, the variations of leaf turgor pressure were closely related to environmental factors in P. tomentosa, and there was a high degree of synergistic change with the sap flow on sunny days. Therefore, leaf turgor pressure can potentially serve as a diagnostic indicator of water deficit.

Key words: leaf turgor pressure, ZIM-probe, sap flow velocity, water stress, Populus tomentosa