不同来源牛枝子种子硬实破除方法的研究

Study on Hardseedness Breaking of Different Seed Lots of Lespedeza potaninii

采用浓硫酸、热水和液氮3种人工破除硬实技术,在室内模拟牛枝子适生地水热条件,对2007、2008年采自内蒙古阿拉善左旗和2008年甘肃榆中栽培的牛枝子种子进行处理,以探讨同一种群不同年份和非种源地栽培一年后的牛枝子种子的硬实程度及其破除的最佳方式。结果发现：（1）采自阿拉善左旗（2007、2008年）和甘肃榆中的牛枝子初始硬实率存在显著差异,分别为98%、93%和86%。（2）阿拉善左旗和甘肃榆中的牛枝子种子对硫酸、热水和液氮处理的响应不同,浓硫酸处理的效果显著优于其它2种方法,普遍适宜于所有种批的最佳浓硫酸处理时间为25-30 min。（3）模拟温度和湿度处理表明,高温（60℃,60/20℃）和5%湿度的环境是牛枝子种子硬实破除的关键环境因素。

To study the degree of hardseedness,variation of breaking requirements in Lespedeza potaninii grown in different environments,we collected three seed lots of L.potaninii in Alxa in 2007 and 2008,Yuzhong in 2008.The seeds were treated with each of three artificial breaking techniques of hardseedness：sulfuric acid,hot water and liquid nitrogen.In addition simulating main climatic condition of Alxa：temperature（20-60℃,30/20-60/20℃） and soil humidity（0,2% and 5%） were also applied to each seed lot.The results showed there were significant difference of hardseedness percentage among seed lots which were 98%,93% and 86%,respectively.Moreover,the responses of three seed lots to sulfuric acid,hot water,liquid nitrogen were different.The treatment of sulfuric acid with 25-30 min was the best method to break hard seed for all seed lots tested.The simulation of temperature and moisture experiment showed that the combination high temperature（60℃,60/20℃）with moisture（5%）was the key environmental factor of hardseedness release in L.potaninii.