外源H_(2)S供体NaHS浸种对盐碱胁迫下裸燕麦种子萌发特性的影响

Effect of Soaking Seeds with NaHS on Seed Germination Characteristics of Naked Oat under Saline-Alkali Stress

硫化氢(H_(2)S)信号在作物种子萌发和逆境响应中发挥着重要作用。为探讨外源H_(2)S供体NaHS浸种对盐碱胁迫下作物种子萌发的影响,以裸燕麦(Avena nude)为材料,用不同浓度NaHS(0、50、100、200和400μmol·L^(-1))浸种8 h后分别在浓度为0、15、30、45和60 mmol·L^(-1)的混合盐碱(NaCl∶Na_(2)SO_(4)∶Na_(2)CO_(3)∶NaHCO_(3)摩尔比为12∶8∶1∶9)胁迫下进行种子萌发试验,分析其发芽率(Gp)、发芽指数(Gi)、活力指数(Vi)、平均发芽时间(MGT)、幼苗干重(SDW)和隶属函数综合评价值(D)的变化。结果表明:盐碱浓度和NaHS浓度及两者的交互作用对Gp、Gi、Vi、MGT、SDW和D值存在显著(P<0.05)或极显著(P<0.01)的影响。随着盐碱浓度提高,Gp、Gi、Vi、MGT、SDW和D值呈显著下降变化。与0μmol·L^(-1) NaHS对照(CK)相比,50和100μmol·L^(-1) NaHS不同程度提高了0 mmol·L^(-1)盐碱胁迫下的Gp、Gi、Vi和D值;50μmol·L^(-1) NaHS显著提高了30 mmol·L^(-1)盐碱胁迫下的Gp;50和100μmol·L^(-1) NaHS不同程度提高了15、30和45 mmol·L^(-1)盐碱胁迫下的Gi;50μmol·L^(-1) NaHS显著提高了30 mmol·L^(-1)盐碱胁迫下的Vi;50和100μmol·L^(-1) NaHS显著提高了45 mmol·L^(-1)盐碱胁迫下的D值;其他处理的各发芽指标值与CK的差异不显著或显著降低。这些结果说明,适宜浓度NaHS浸种能够缓解盐碱胁迫对裸燕麦种子萌发的抑制,其中以50μmol·L^(-1) NaHS缓解45 mmol·L^(-1)以下浓度盐碱胁迫的效果最佳,200和400μmol·L^(-1) NaHS加重盐碱胁迫对种子萌发的抑制,NaHS对高浓度(60 mmol·L^(-1))盐碱抑制裸燕麦种子萌发无缓解作用。

Hydrogen sulfide(H_(2)S)signaling plays an important role in seed germination and stress response.To explore the influence of soaking seeds with sodium hydrosulfide(NaHS,a donor of H_(2)S)on the seed germination of crops under saline-alkali stress,naked oat(Avena nude)seeds were selected as experimental material which were soaked with different concentration(0,50,100,200 and 400μmol·L^(-1))of NaHS for 8 h,and then germinated in different concentrations of mixed saline-alkaline(the mole ratio of NaCl∶Na_(2)SO_(4)∶Na_(2)CO_(3)∶NaHCO_(3) is 12∶8∶1∶9)solution(0,15,30,45 and 60 mmol·L^(-1))in petri dishes in incubator.Changes in germination percentage(Gp),germination index(Gi),vigor index(Vi),mean germination time(MGT),dry weight of seedlings(SDW)and comprehensive evaluation value of membership function(D)were analyzed.The effects of different concentrations of saline-alkali and NaHS and their interaction on Gp,Gi,Vi,MGT,SDW and D were significant(P<0.05)or extremely significant(P<0.01).The Gp,Gi,Vi,MGT,SDW and D decreased significantly with the increase of saline-alkali concentration.Compared with 0μmol·L^(-1) NaHS(CK),50 and 100μmol·L^(-1) NaHS increased the Gp,Gi,Vi and D under 0 mmol·L^(-1) saline-alkali stress to different degrees.The 50μmol·L^(-1) NaHS significantly increased the Gp under 30 mmol·L^(-1) saline-alkali stress.The 50 and 100μmol·L^(-1) NaHS increased Gi under 15,30 and 45 mmol·L^(-1) saline-alkali stress to different degrees.The 50μmol·L^(-1) NaHS significantly increased Vi under 30 mmol·L^(-1) saline-alkali stress.The 50 and 100μmol·L^(-1) NaHS significantly increased D under 45 mmol·L^(-1) saline-alkali stress.However,the germination index values of other treatments were not significantly different or significantly reduced.These results suggest that soaking the seed with NaHS of appropriate concentration could relieve the inhibition of saline-alkali stress on seed germination of naked oats,optimal effects were reached at NaHS concentrations of 50μmol·L^(-1) under saline-alkali stress at below 45 mmol·L^(-1),200 and 400 mmol·L^(-1) NaHS aggravated the inhibition of salinityalkali stress on seed germination,and NaHS had no palliative effect on the inhibition of seed germination of naked oat under high concentration of salinity-alkali stress(60 mmol·L^(-1)).