试验利用恒温 5 0℃热空气干燥法 ,分别使各树种种子含水率下降到 9%至 1%时对种子发芽率和活力及生理生化特性的影响。结果表明 :杉木种子水分降至 4%～ 5 % ,马尾松种子水分降至 5 %时 ,种子发芽率、活力均保持较高水平 ,细胞膜保持较高的完整性 ,α -淀粉酶、脱氢酶活性和呼吸强度都较高 ,由此可见 ,4%～ 5 %、5 %分别为杉木、马尾松种子的下限超干燥含水率 Experiments using hot air drying at a constant temperature of 50 ℃, respectively, the seed moisture content of each tree down to 9% to 1% of the seed germination rate and vigor and physiological and biochemical characteristics. The results showed that when the water content of Chinese fir seeds was reduced to 4% ~ 5% and the water content of Pinus massoniana decreased to 5%, the seed germination rate and vigor of seeds maintained a high level while the cell membrane maintained high integrity. The α - amylase, dehydrogenation Enzyme activity and respiration intensity are high, we can see that 4% to 5%, 5%, respectively, the lower limit of ultra-dry water content of Chinese fir, Pinus massoniana