外源Si对NaCl胁迫下肥皂草种子萌发及幼苗生长的影响

摘要

We studied the effects of exogenous silicon ( K2 SiO3 ) on soapwort seed germination and growth under salt stress .The exogenous silicon significantly improved the germination rate ( GR) , germination energy ( GE) , germination index ( GI) and vigor index ( VI) of soapwort seed exposed to three concentrations of salt stress , also increased the length of hypocotyls and radicle of seedlings and dry weight of seedlings added , and performed best treated with 0.8-1.2 mmol· L-1 exogenous silicon.Exposed to three concentrations of salt stress , the exogenous silicon treated with 0.8-1.2 mmol· L-1 exogenous sil-icon significantly promoted seed germination and seedling growth .When the concentration of silicon exceeded 1.2 mmol· L-1 , the effect of relieved salt stress was decreased gradually .Under 80 mmol· L-1 salt stress, when the concentration of exogenous silicon was more than 1.6 mmol· L-1 , there was no effect of relieved salt stress and inhibiting seed germination and seedling growth of soapwort .%研究NaCl胁迫下，外源Si（ K2 SiO3）对肥皂草种子萌发和幼苗生长的影响。结果表明：在3个浓度梯度（40、80、120 mmol· L－1）的NaCl胁迫下，外源Si可不同程度地提高肥皂草种子的发芽率、发芽势、发芽指数和活力指数，增加胚轴、胚根长度及幼苗干质量，其中，以0．8～1．2 mmol· L－1的外源Si处理效果最佳。在3个梯度的NaCl胁迫下，0．8～1．2 mmol· L－1的外源Si均可显著促进种子萌发和幼苗生长，缓解NaCl胁迫对肥皂草种子和幼苗的伤害；当外源Si浓度超过1．2 mmol· L－1时，缓解NaCl胁迫作用逐渐降低。在80 mmol· L－1 NaCl胁迫下，当外源Si浓度超过1．6 mmol· L－1时不具有缓解NaCl胁迫作用，反而抑制肥皂草种子萌发和幼苗生长。