Abstract: Silver Linden(Tilia tomentosa＜)seed has the character of complex dormancy.Based on the dormant mechanism of silver linden seed and the previous results with a single factor experiment on breaking seed dormancy,an orthogonal design L ₂₇(3¹³)with four factors(seeds shucked off pericarp dipping in water,GA3 treatment,6-BA treatment and stratification)and three levels was conducted to explore the optimal technical combination for quickly breaking seed dormancy,promoting germination and seedling vigorous growth.The result indicated:the optimal combination of factor and level was 1)shucking off pericarp by machine;2)scalding seeds for 2 s with 100 ℃ boiling water,then soaking in room temperature water for 24 h;3)soaking in 200 mg·L^-1 GA₃ and 6-BA solution,respectively for 24 h;4)stratification in varying temperature,I.e.warm temperature(10～15 ℃)for 5 d,then in low temperature(0～5 ℃)for 15 d.Seeds treated with this combination germinated after 20 d.The germinating rate in nursery garden was 71.2%,and the seedlings grew vigorously.

Key words: Tilia tomentosa, seed, dormancy releasing