Water potential and transpiration with decreasing soil moisture in Photinia frasery potted seedlings

Diurnal soil and leaf water potential as well as transpiration rate of 2-year-old potted seedlings of Photinia frasery were studied with decreasing soil moisture conditions during the testing period.Also,a correlation analysis between the transpiration rate of the soil versus leaf water potential was conducted.Results indicated that the change of daily soil and leaf water potential was a'V'shape with daily fluctuation range increasing as drought stress rose during the testing period.As soil water potential decreased over the experimental period,the daily mean transpiration rate decreased with daily fluctuation range decreasing and the transpiration peak occurring sooner.The correlation analysis showed that the correlation between transpiration rate and soil water potential was extremely significant(r = 0.804,P0.01),while that of transpiration rate and leaf water potential was significant(r = 0.566,P 0.05=).