Abstract: In order to improve the quantity and quality of white poplar seeds produced by sexual hybridization, the branches of maternal plant were treated with rare-earth. The results indicate that there is a significant promotive effect on seed setting rate in the branches soaked with rare-earth at 200ppm or 500ppm concentration. The length and thickness of fruite ear are also promoted slightly at these concentrations. The effects of rare-earth treatments on the weight of 1000 seeds and germination rate are not obvious.

Key words: White poplar, Sexual hybridization, Rare-earth, Seed settingrate