蒙古扁桃种子雨散布及种子萌发特性研究

以蒙古扁桃（Amygdalus mongolica Maxim）种群和种子为研究材料，通过物理特性、休眠特性、萌发特性的研究，探讨种群致濒因素。结果表明，蒙古扁桃种子比重、体积和千粒重大，散布时间较集中，散布格局是聚集型散布，散布主要依靠自身重力，靠动物散布和水力作用的散布，使种子能传播较远的距离。制约种子萌发的主要因素是种皮障碍和生理休眠（10%），采用35 ℃条件下处理72 h后机械破除果皮可破除种子休眠，种子低温（2~5 ℃）层积处理能极显著（P <0.01）提高活力，种子变温（5~10 ℃）层积能极显著（P <0.01）提高发芽率和活力，种子萌发对光照不敏感。蒙古扁桃种子休眠较浅，种子萌发所需温度较低，冬前进入土壤库的种子迅速萌发，因不能度过严冬而死亡，是致濒的主要原因。封冻时进入土壤库的种子，在种皮保护下越冬，仍有很高成苗率，开展人工繁育是拯救蒙古扁桃资源的直接措施。

A study on spatial distribution pattern of seed rain and seed germination characteristics of endangered plant Amygdalus mongolica

In this article,the Arnygdalus mongolica population and seeds are taken as the research object to explore its endangered factors based on the study on its physical properties and characteristics in dormancy and germination.The results showed that Amygdalus mongolica seed has large volume,heavy specific weight and grain big.It spreads in a rather aggregative pattern,which mainly relies on its own gravity,animal and water,so it could spread much further.The main factors that restrict seed germination are seed coat barriers and physiological dormancy (accounting for about 10 percent).The physiological dormancy of the seed may be stopped by peeling mechanically after 72-hours exposure in 35 ℃.Seed stratification in low temperature (2-5 ℃) will effectively improve its vitality.Meanwhile,seeds thermocline (5-10 ℃) will increase its germination rate.However,seed germination is not sensitive to light.The dormancy term of Amygdalus mongolica seed is quite short and seed germination could happen in low temperature,so the seed put into soil library before the winter would germinate quickly and die in the chilly winter,which makes Amygdalus mongolica become an endangered species.However,the seed putting into soil library during frozen period can survive and has a high seedling rate due to the protection of seed coat.In summary,it is proved that artificial breeding is the most effective measure to rescue Amygdalus mongolica from extinction.