低温层积对纳罗克非洲狗尾草种子酶活性及其萌发的影响

摘要

Setaria sphacelata cv.Narok is one of excellent tropical and subtropical forages.However,the deep seeds dormancy restricts the popularization and utilization of the forage.Used one year old Setaria sphacelata cv.Narok under cold stratification treatment and determined its enzyme activity,germination rate and vigor,the results showed that after the cold stratification 30 d,seed dormancy has been completely removed,the seed germination rate and vigor index were 75% and 0.026 3,respectively,which were 2.08 times and 2.27 times compared with the control and had a significant difference (P <0.01).The SOD activity of seed decreased and then increased to the stable level.After cold stratification 60 d,the SOD activity reached lowest and reduced 9.07 times compared with the control.The POD activity fluctuated a-long with time change,but the change was not obvious (P >0.05).The CAT activity had no changes before cold stratifi-cation 90 d (P >0.05)and then decreased.%为探究低温层积对纳罗克非洲狗尾草(Setaria sphacelata cv.Narok)种子酶活性及其萌发的影响,将一年龄纳罗克非洲狗尾草生产的种子进行低温(4℃)层积不同时间处理,并测定在不同处理下种子的酶活性、发芽率及活力水平。结果表明：纳罗克非洲狗尾草种子在低温层积处理最佳时间为30 d,在此处理条件下,种子休眠已完全解除,此时种子的发芽率和各项活力指数分别达到75%和0.0263,是对照(低温层积处理0d)的2.08倍和2.27倍,差异达到极显著水平(P <0.01)；种子超氧化物歧化酶(SOD)活性,呈先下降后升高并逐渐稳定的趋势,低温层积60 d 降至最低水平650.800 U/g FW·h,较对照降低了9.07倍；过氧化物酶(POD)活性随时间的推移波动变化,但变化不明显(P >0.05)；过氧化氢酶(CAT)活性在层积处理90 d 前无显著变化(P >0.05),之后逐渐下降。