摘要
水曲柳 (FraxinusmandshuricaRupr .)是珍贵用材树种。搜集母树上自然散落的种子 ,置于不同的温度、湿度及不同的埋藏环境条件下 ,观测种子的生活力动态。结果表明 :冰冻低温条件下 (- 10～ - 5℃ ) ,种子生活力变化不大。但在室内常温条件下 (16～ 2 8℃ ) ,生活力下降很快。自然环境温度中 (- 19 6℃～ 2 0 5℃ ) ,生活力下降速度介于上述二者之间。一年后 ,生活力分别降低 2 0 2 %、 5 1 95 %和 32 60 %。浸泡在水中的种子 ,7周后生活力降低 40 95 % ,三个月后仍有 15 87%的种子可维持生活力。处于潮湿环境的种子 ,容易霉变腐烂 ,7周后种子生活力丧失 90 48%。埋藏在土壤和枯落物中的种子 ,一年后种子生活力下降约 75 %。
Manchurian ash (\%Fraxinus mandshurica\% Rupr.), as an important timber species, its seed dormancy stage was relatively long. In natural condition, its seed can not germinated until 3rd year after dispersal from parent tree. Among the stages the seed viability would vary with different environmental conditions. We collected seeds from natural forest when the seed dispersing, and then stored them for studying dynamics of seed viability in different environments. The study showed that variation of seed viability was not clearly (only decreased 2 02%) in lower temperature (-10～-5℃), however, apparently decrease was found in higher temperature (16～28℃) and in natural condition (-19 6℃～20 5℃),the decreased rates were 51 95% and 32 60%, respectively. When seed were soaked in water, its viability reduced 40 95% after 7 weeks, but 15 87% of seeds can still conserve viability after 3 months. If seeds were put in moist condition, their vitality was damaged quickly, maybe caused by pathogens or insects, the viability of those seeds lost 90 48% after 7 weeks. The Seed viability, which buried in soil or litter, lost about 75% in a year.
