两种菊属植物对渐进与非渐进盐胁迫的响应

以两种菊属野生植物'菊花脑'(Dendranthema nankingense)和'乙立寒菊'(D.indicum var.maruyamanum)幼苗为材料,通过Hogland营养液水培试验研究了120和180 mmol·L NaCl的渐进和非渐进胁迫处理对幼苗叶片受害程度及植株生物量、根系活力、叶片叶绿素含量、相对电导率和丙二醛含量的影响,以探讨它们对盐冲击的生理响应规律.结果显示:(1)在两种浓度盐胁迫下,两种菊属植物的整株鲜重、根系活力、叶片叶绿素含量大多显著下降,而同期的叶片丙二醛(MDA)含量、相对电导率显著增加;渐进盐胁迫下材料受害程度均轻于非渐进胁迫;盐胁迫浓度越大,各指标变化幅度越大,且两种胁迫方式下各指标的差异亦越大;(2)'菊花脑'对盐胁迫敏感,而'乙立寒菊'对盐胁迫的耐性较强;相同盐胁迫浓度下,非渐进胁迫与渐进胁迫间的差异在盐敏感材料上表现较明显.研究表明,两种菊属植物均存在盐冲击现象,并以耐盐性弱的材料表现更加突出,且高盐胁迫下植物所受的冲击伤害更明显.

Influences of Rapid and Gradual NaCl Stress on Two Dendranthema Species

Dendranthema nankingense and D.indicum var.maruyamanum were irrigated with Hogland culture medium supplied with NaCl rapidly and gradually at concentrations of 120 and 180mmol·L~(-1) respectively,The effects of NaCl stress on the leaf morphological injury extent,biological weight,root vigor,leaf chlorophyll content,relative conductivity and malondialdehyde (MDA) content were investigated,so as to find out the responding rule of salt shock on two wild species from Dendranthema.The results showed that under salt stress,biological weight,chlorophyll content and root vigor decreased evidently,while the leaf relative conductivity and MDA content of two species increased significantly.The gradual salt stress did less damage on plant than that of rapid salt stress.The increment or decrement of all indexes increased with the increase in NaCl concentrations,so did the differences of most indexes between rapid NaCl stress and gradual NaCl stress.D.nankingense is sensitive to salt stress,while D.indicum var.maruyamanum is slat tolerant one.Both species showed salt shock effect,compared to salt tolerant specie,the salt sensitive specie showed much salt shock effect under same salt concentration,also more obvious salt shock effect was observed in two species under higher salt concentration.