Abstract: Populus bachofenii×P.pyramidalis ROZ is a new fast-growing timber production and ornamental variety introduced from Russia. Its permeation of plasma membranes and the activity of protective enzymes were studied by taking 1 year old tissue-culture derived plants as test materials that were treated by different drought stress. The results illustrated that the permeation of plasma membranes of P.bachofenii×P.pyramidalis ROZ was increased under drought stress condition, its relative electric conductivity increased along with the decrease of soil moisture and the time prolong of drought stress. Meanwhile, the membrane permeability and the protective enzyme activities after restoration of water supply were restored to the level under normal condition. Therefore, P.bachofenii×P.pyramidalis ROZ had good ability to adapt to drought stress in case that field moisture content was 20%~95%(the absolute volume moisture content was 11.5%~43.7%), and the absolute optimum volume moisture content was 27.6%~29.9%.

Key words: Populus bachofenii×, P.pyramidalis ROZ, drought stress, protective enzyme