入侵植物节节麦种子休眠原因及解除方法研究

Study on the Causes and Release of Seed Dormancy of an Invasive Plant Aegilops tauschii

本研究以节节麦(Aegilops tauschii Coss.)种子为试材,结合种子透水性及萌发抑制物的测定探究其休眠原因,并通过外源赤霉素(gibberellin,GA 3)及温水浸种处理筛选其最佳破眠方法。结果表明:完整种子的吸水率明显高于去颖壳种子,且温水浸种能显著提高种子发芽率,说明颖壳引起休眠的原因为机械阻碍,与其透水性无关;颖壳、种子的水及甲醇浸提液均在浓度为0.08 mg·L-1时,对小麦种子萌发及生长表现出显著的抑制作用,说明颖壳中存在的水溶性及种子内溶于有机溶剂的萌发抑制物共同作用是节节麦种子休眠的主要原因;以500 mg·L-1 GA 3浸种24 h(完整种子)、300 mg·L-1 GA 3浸种48 h(去颖壳种子)及45℃温水浸种5 min(完整种子)的破眠效果较为显著。

Through the investigations on the physiological and biochemical changes in seed permeability and extraction of inhibitors of germination,and pretreatment with gibberellin(GA 3)and warm water before germination,the mechanism and release methods of an Invasive Plant Aegilops tauschii seed dormancy were discussed.The results showed that:firstly,the water absorption rate of whole seeds was significantly higher than that of deglumed seeds,and warm water soaking treatment significantly increased the germination rate of seeds.All of these indicated that the glume caused dormancy is through mechanical obstruction and independent of its water permeability.Secondly,the water extract of glume and methanol extract of seeds all showed a significant inhibitory effect on wheat seed germination and growth at a concentration of 0.08 mg·L-1.All of these indicated that the main reason of the seed dormancy of A.tauschii might resulted from the joint effect of water-soluble germination inhibitory substances in seed glume,alcohol-soluble germination inhibitory substances in seed.At last,Seed germination percentage was significantly improved by treating the whole seeds with 500 mg·L-1 GA 3 for 24 h,warm water(45℃)for 5 min,or 300 mg·L-1 GA 3 for 48 h with glume removal.