Effect of Water Stress on Biomass Allocation of Simmondsia chinensis Seedlings

The biomass allocation of 16monthold pot grown seedlings of Simmondsia chinensis under greenhouse conditions with artificially simulated drought stresses was studied with Thorough Random Experiment Design.Seven provenances of S.chinensis were individually treated with seven different levels of drought stress by controlled irrigation.The results were as follows: Compared to the control, the total seedling biomass of the seven provenances under the same drought stress dropped by 2640%, 3722%, 3026%, 2011%, 2722%, 3041% and 3417% respectively.With the development of drought stress, the ratio of aboveground biomass to the total biomass decreased whereas the ratio of underground biomass to the total biomass increased, the variance of the seven 7 provenances was 164%, 200%, 231%, 215%, 185%, 267% and 214% respectively.The ratio of root biomass to the aboveground biomass of the seven provenances under drought stress was individually 11068%, 14754%, 17196%, 15236%, 15229%, 22611% and 15276% of the control.