Birdsfoot trefoil (Lotus corniculatus L.) is a nutritional legume species.It adapts to slightly acidic,droughty,infertile or wet soils and widely distributes in China.However,seed dormancy results in poor subsequent stand establishment.Seeds were collected from sub-alpine meadow of QinghaiTibetan plateau.The objective of this study was to break dormancy by treating seeds with scarification,chemical soaking and gibberellic acid (GA3) immersion as well as freezing.Results indicated average hard seed rate of Birdsfoot trefoil was up to 92.3％ and coat thickness of dormant seeds was (65.63 ± 2.26)μ m,which was 60.4 percent larger than control.Mechanical scarification significantly removed seed dormancy,and the final germination percentage (FGP) was increased from 8.7 ％ to 85 ％.Chemical scarification treated by concentrated sulphuric acid (98％ H2SO4) of 5,15,25 min was also effective in reducing hard seed and improving seed germination.Moreover,15 and 25 min-soaking were better compared with control.However,no significant effects were observed between 40 ％ NaOH treatment and control.In addition,the higher germination rate was achieved by use of gibberellic acid or combination of cold-wet storage and GA3,-4 ℃,-20 ℃ and Ultra-low temperature freezing.%百脉根(Lotus corniculatus L.)是一种富合营养物质的豆科牧草,适应酸性、干旱及贫瘠的土壤,在我国分布广泛,然而种子的休眠特性限制了它的利用.为此,以青藏高原亚高山草甸的野生百脉根种子为试验材料,通过擦破种皮、化学腐蚀、低温冷冻等方法研究打破种子休眠的办法.研究结果表明,野生百脉根种子的硬实率高达92.3％,种皮厚度为(65.63±2.26)μm,比对照高出60.4％ (p＜0.01),可见野生百脉根种子以种皮厚、透水性差为特点.试验还发现,擦破种皮后,种子的发芽率由8.7％提高到85％;浓度为98％的浓硫酸浸泡5,15,25 min均能有效地降低种子的硬实率,提高发芽率,其中以15,25 min处理效果最好,相比而言,浓度为40％的NaOH处理效果不明显.GA3、低温湿沉积+GA3及-4℃,-20℃及液氮超低温冷冻能显著提高发芽率.
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