抗坏血酸引发对NaCl胁迫下饲用小黑麦种子活力的影响

Effects of Ascorbic Acid Priming on Seed Vigor of Forage Triticale under NaCl Stress

[目的]探讨NaCl胁迫下外源抗坏血酸(ascorbic acid,AsA)引发对饲用小黑麦种子活力的影响。[方法]以饲用小黑麦“冀饲3号”的种子为试验材料,分别在浓度为0.5、1.0、1.5、2.0 mmol/L的AsA溶液中引发处理0(CK)、4、8、16、24 h,然后在浓度为100 mmol/L的NaCl胁迫下进行发芽试验,对种子的发芽率(germination percentage,Gp)、发芽指数(germination index,Gi)、平均发芽时间(mean germination time,MGT)及幼苗活力指数(seedlings vigor index,SVI)进行分析。[结果]外源AsA的处理浓度和引发时间对饲用小黑麦种子的Gp、Gi、MGT及SVI均存在极显著(P<0.01)影响,此外,两者的组合效应对SVI的影响达到显著(P<0.05)水平,对Gp、Gi和MGT的影响达到极显著(P<0.01)水平。浓度为1.0 mmol/L的AsA引发4 h时,饲用小黑麦种子的Gp、Gi以及SVI均达到最高值,MGT最低;浓度为0.5~2.0 mmol/L的AsA引发24 h时,饲用小黑麦种子的Gp、Gi以及SVI均低于其他引发时间,而MGT高于其他引发时间。[结论]AsA引发对NaCl胁迫下饲用小黑麦种子活力的影响与AsA的浓度、引发时间以及二者的协同作用紧密相关。采用1.0 mmol/L的AsA溶液,在引发时间为4 h的条件下,对处于100 mmol/L NaCl盐胁迫环境下的饲用小黑麦种子,能最有效地提升其活力水平。

[Objective]The aim of the present study was to assess the effects of exogenous ascorbic acid(AsA)priming on seed vigor of forage triticale(×Triticosecale Wittmack)under NaCl stress.[Method]Forage triticale′Jisi No.3′seeds were primed in AsA solutions at the concentrations of 0.5,1.0,1.5 and 2.0 mmol/L for 0(CK),4,8,16 and 24 h,respectively,and were then germinated under NaCl stress at a concentration of 100 mmol/L.The germination percentage(Gp),germination index(Gi),mean germination time(MGT)and seedlings vigor index(SVI)of the seeds were determined and statistically compared.[Result]The priming concentration or duration of the exogenous AsA had extremely significant(P<0.01)effects on Gp,Gi,MGT and SVI of the forage triticale seeds.In addition,the mutual combination effect of both reached significant(P<0.05)level on SVI and extremely significant(P<0.01)level on Gp,Gi and MGT.The highest values of Gp,Gi and SVI as well as the lowest value of MGT were observed in the seeds with AsA priming for 4 h at a concentration of 1.0 mmol/L.In the AsA priming concentration range of 0.5-2.0 mmol/L,the seeds had lower Gp,Gi and SVI as well as higher MGT when they were primed for 24 h in comparison to those at the other priming times.[Conclusion]The effects of AsA priming on seed vigor of forage triticale under NaCl stress were closely related to the priming concentration and duration as well as their synergistic action.Priming with AsA at a concentration of 1.0 mmol/L for 4 h exhibited the most effective improvement in seed vigor of forage triticale under a salt stress environment of 100 mmol/L NaCl.