【摘要】 针对羊草种子萌发率低的问题,对43份不同种质的羊草种子,在两种变温条件下的萌发率进行了研究,并对恒温、变温、变温时长、变温时段对羊草种子萌发率的影响进行了测试。结果表明,羊草种子萌发率受种质影响较大,不同种质的羊草种子萌发率变幅为10%~95%,差异极显著。此外,羊草种子萌发亦受温度调控,恒温条件下(16、20、22、28、37℃)种子萌发率均较低,变温28℃(12h)/16℃(12h)则显著提高了种子萌发率,增幅为50%~90%。且变温处理对种子萌发有"时间剂量累加效应",即变温处理时间越长,萌发率提高越大。在第1、2天时变温处理的种子萌发率与恒温对照相比,达到极显著差异,且在24h内接收低温信号的剂量时长在2~16h,高于16h萌发率不随时间增加,低于2h萌发率提高不显著。此外还发现,萌发24h之内,羊草种子对变温处理有一个敏感的"窗口期",即8~12h,在这个时段内变温处理对种子萌发率提高最为显著。更多还原

【Abstract】 To clarify the reasons for low seed germination rate,germination of 43 different germplasm lines of sheep grass was studied at constant temperatures of 16,20,22,28 and 37℃,and under a variable temperature regime of 28℃(12 h)and 16℃(12 h).It was found that seed germination percentage of sheep grass differed between germplasm lines,with values ranging from 10% to 95%.Seed germination was low under constant temperature conditions,while the alternating 28 ℃/16 ℃ treatment increased the seed germination rate by50%-90%(P<0.01).Furthermore,the longer the daily high temperature exposure,the higher germination rate was.The seed germination rate was increased very significantly(P<0.01)on 1 day or 2 days of variable temperature treatment,compared with the constant temperature control.However,on the first day of germination,variable temperature less than 2 hours cannot significantly promotes germination,and germination rate improves significantly in 8-12 hours treatments,which considers as the"window period".更多还原