Abstract: We addressed fourclone poplar pollen viability under different storage temperatures with pollen in vitro method, and the feasibility of poplar pollen in cross breeding after stored in ultralow temperature for one year. Experimental results show that germination rate of poplar pollen is maximal after cultured for 28 hours in vitro. The germination rate of four poplar clone pollenis highest after 3 months storage at -20 ℃, 36% for Populus alba×P. glandulosa ‘84K’, 35.2% for (P. tomentosa×P. bolleana)×P. canescens, 39.2% for P. deltoides cl. ‘Zhonghe 1’, and 41.9% for P. nigra cv‘ Italica’. The pollen that is stored at -80 ℃ for one year still has viability, and can properly pollinate.We can therefore get the regular seeds.

Key words: poplar, pollen, viability, storage