Abstract: The strong dormancy characteristic of Leymus secalinus leads to low germination percentage and limits its application in production practice. In this paper,different concentrations of 6-BA were used to prime the seeds of L.secalinus at different time. Through analyzing the changes of germination ability,storage substances and endogenous hormones,the causes of seed dormancy were disscussed,and the methods of breaking dormancy were sought. The results showed that the germination percentage of L.secalinus reached the highest,51.03%,when primed with 60 mg·L^-1 6-BA for 36 h,The storage substances and endogenous hormones of the seeds primed with 36 h of different 6-BA concentrations were determined.The results showed that the soluble sugar content and the activity of amylase and lipase were the highest,the starch content was the lowest in seeds of L.secalinus when primed with 120 mg·L^-16-BA.The activity of glucose-6-phosphate dehydrogenase and content of gibberellin were maxmal when primed with 60 mg·L^-1 6-BA. Therefore,the method that seeds were primed with 60 mg·L^-1 and 120 mg·L^-1 6-BA at 36 h lead to the activation of endogenous hormones and potential enzyme systems,enhance metabolism in seeds,and provide nutrients for seed germination. Therefore,the method can be used to break the dormancy of L. secalinus seeds.

Key words: Leymus secalinus, 6-BA, Prime, Endogenous hormones, Storage substance

摘要： 赖草（Leymus secalinus）种子的强休眠特性使其发芽率很低，严重制约了其在生产实践中的应用。本试验利用不同浓度的6-苄基腺嘌呤（6-benzyl adenine，6-BA）对赖草种子进行不同时间的引发处理，通过研究其萌发能力、贮藏物质及内源激素的变化，探讨其休眠的原因及6-BA引发对赖草种子萌发的影响，为破除种子休眠提供依据。结果表明：60 mg·L^-1的6-BA引发36 h，赖草种子的发芽率最大，为51.03%，是清水引发处理的2.51倍。测定引发36 h赖草种子的贮藏物质和内源激素的变化结果显示，6-BA浓度为120 mg·L^-1引发的种子可溶性糖含量、淀粉酶活性、脂肪酶活性最大，淀粉含量最低。60 mg·L^-1的6-BA引发种子内的葡萄糖-6-磷酸脱氢酶活性最大，且赤霉素含量也最高。综上所述，60 mg·L^-1、120 mg·L^-1的6-BA引发36 h大大活化了种子的内源激素，在激素的作用下酶系活化，促使贮藏物质分解，为种子萌发提供营养物质，使赖草种子的发芽率达到最大。因此，可利用60 mg·L^-1和120 mg·L^-1的6-BA引发36 h的方法进行赖草种子休眠的破除。

关键词: 赖草, 6-BA, 引发, 内源激素, 贮藏物质