野牛草种子休眠原因分析

Analysis on Factors Causing the Seed Dormancy of Buchloe dactyloides(Nutt.) Engelm.

以"中坪一号"野牛草(Buchloe dactyloide(Nutt.)Engelm)为实验材料,通过硝酸钾、赤霉素引发实验、种子解剖、电镜扫描、能谱分析等手段,分析限制野牛草试验材料发芽率低下的原因。种子引发试验参照碱蓬(SuaedaglaucaBge.)种子解除休眠的赤霉素(GA3)和硝酸钾(KNO3)浓度,分设0.5%硝酸钾和20 mg/kg4、0 mg/kg、60mg/kg、100 mg/kg赤霉素等处理。结果表明:野牛草种子休眠类型属机械休眠与生理休眠同时存在,且生理休眠占主导地位的综合休眠;野牛草种球外部的颖苞对种子的强烈束缚引起了机械休眠,而生理后熟是野牛草种子生理休眠的直接原因;赤霉素对休眠程度较深的去颖苞种子引发效果最好,且以60 mg/Kg浓度为最佳。

The factors causing buffalograss seed dormancy were studied using the seeds of Buchloe dactyloides（Nutt.） Engelm.cv.Zhongping No.1 by KNO3 and gibberellic acid（GA3） priming treatment,seed dissection,electron microscope scanning,and energy spectrum analysis,etc.According to studies on relieving dormancy of Suaeda glauca（Bunge） Bunge seeds,the buffalograss seeds were treated by 0.5% KNO3 and GA3 at 20,40,60,and 100 mg·kg-1 level.The results show that the dormancy type of buffalograss seeds was compositive of both mechanical and physiological dormancy with the dominance of latter.The strong bondage from glumes caused mechanical dormancy of seeds,while physiological aftermature of seeds was the direct reason.The best way to promote seed germination was application of GA3 to seeds without glumes with the optimal GA3 concentration at 60 mg·kg-1.