钙离子对海盐和NaCl胁迫下菊芋幼苗生理特征的响应

Effects of Calcium Ion on Physiological Characteristics of Jerusalem Artichoke Seedlings under Seawater Salt and NaCl Stresses

用不同浓度CaCl2(5 mmol/L,10 mmol/L,20 mmol/L)对处在相同含盐量的海盐和NaCl两种盐胁迫处理下的菊芋幼苗进行化学调控,研究了钙离子对两种盐处理的菊芋幼苗的生物量、SOD活性、MDA含量、相对电导、叶绿素含量和Pn的影响。研究结果表明:(1)当菊芋处于海盐和NaCl两种盐胁迫下时,菊芋的生物量、SOD活性、叶绿素含量和Pn均显著降低,MDA含量和相对电导显著增加;(2)当施入钙离子后,两种盐对菊芋幼苗的胁迫不同程度降低,其中以中浓度的钙离子效果最好,使菊芋的生物量、SOD活性、叶绿素含量和Pn显著增加,MDA含量和相对电导显著降低,当CaCl2浓度大于10 mmol/L时,则钙离子对盐胁迫的缓解作用降低,说明适量的钙离子有效缓解了盐胁迫所致的氧化损伤,从而抑制了脂质过氧化作用,增加叶绿素含量,维持较高的光合速率,增加干物质积累,从而使生物产量增加;(3)在5 mmol/L,10 mmol/L钙离子浓度下,钙离子对海盐胁迫的缓解作用显著优于NaCl,但在20 mmol/L浓度下,两个处理差异不显著。

A regulation of calcium ion on jerusalem artichoke （JA） seedlings under seawater salt （SWS） and NaCl with the same salt content was made with three calcium ion concentration of 5 mmol/L, 10 mmol/L and 20 mmol/L. The effects of calcium ion on biomass, SOD activity, MDA content, relative conductivity, chlorophyll content and net photosynthetic were studied. The results indicated that： normal metabolism of JA was markedly inhibited by 1.0% SWS and 1.0% NaCl. However, addition of Ca^2＋ could alleviate the effects of SWS and NaCl stresses on JA in different degree, so higher biomass, SOD activity, chlorophyll content and net photosynthetic rate, lower content of MDA and relative conductivity were maintained, especially 10 mmol/L Ca^2＋. Above 10 mmol/L the alleviation decreased. As a result, appropriate concentration Ca^2＋ could significantly protected JA from oxidative damage caused by SWS and NaCl stresses. Therefore, higher SOD activity, chlorophyll content and net photosynthetic rate, lower content of MDA and relative conductivity were maintained. These were propitious to the dry matter accumulation so that the fresh weight was increased significantly. At Ca^2＋ concentration of 5 mmol/L, 10 mmol/L the effect of Ca^2＋ on alleviation of SWS stress was superior to NaCl stress significantly, whereas the two treatments did not have pronounced difference when the concentration was 20 mmol/L.