关键词: 旱生灌木, PV技术, 水分参数, 耐旱性

Abstract: Potaninia mongolica, Reaumuria soongorica, Tetraena mongolica and Zygophyllum xanthoxylon are the super xerophytes in the region from East Alxa to West Erdos. This article makes a measurement of several water parameters of them(ψ_π¹⁰⁰, ψ₀, F₀, RWC⁰ etc.) by PV technique, and makes a comparison and analysis of drought tolerance in hydro-physiology. Following results have been obtained.(1) Potaninia mongolica, Reaumuria soongorica, Tetraena mongolica and Zygophyllum xanthoxylon have different mechanism of drought tolerance. Reaumuria soongorica could adjust osmosis by improving the concentration of cellular solute, but Tetraena mongolica has small cellular volume (low F₀) and strong ability of holding water (high AWC and V_a/V₀).(2) The very low values of ψ_π¹⁰⁰(-3.1302 MPa) and ψ₀ (-3.5074 MPa) in Reaumuria soongorica show that it has strong ability of maintaining large turgor and low water potential.(3) Tetraena mongolica has low F₀ (52.12%), high AWC(87.43%) and high V_a/V₀ (7.8092), which shows that Tetraena mongolica has strong ability of tolerating water deficiency and resisting dehydration.(4) The systems of roots and stems in Potaninia mongolica have the ability of absorbing and transmitting water.(5) Statistical test analysis proved that Pressure-Volume technique has good repetition characters.

Key words: xeric shrubs, PV technique, water parameters, drought tolerance