羊草对不同盐碱胁迫的生理响应

用不同浓度的NaCl(0~700 mmol/L)和Na2CO3(0~200 mmol/L)对羊草进行胁迫处理,通过测定与生长相关的生理指标,从而分析了2种盐对羊草生长的胁迫作用特点。实验结果表明,羊草对NaCl、Na2CO3处理的最高耐受浓度分别是600和175 mmol/L。NaCl、Na2CO3处理不同程度地影响了羊草的营养生长以及物质代谢,具体表现为分蘖率、平均根茎数、相对含水量、相对生长率、叶绿素、氮含量的降低,其中以Na2CO3胁迫处理组尤为明显。NaCl、Na2CO3破坏羊草质膜功能,K 、电解质外渗率随着盐浓度的增加而增加,这一结果表明质膜的透性增大。TTC(红四氮唑)含量水平反映了NaCl、Na2CO3处理对羊草根系活力的影响,2种盐的处理降低了根系活力,特别是在Na2CO3处理组中,当Na 浓度超过200 mmol/L时,植株根系TTC含量几乎为0。以上各生理指标表明:NaCl、Na2CO3不同程度地影响了羊草生长、光合作用以及物质代谢,其中以Na2CO3处理更为严重。

Different physiological responses of Aneurolepidium chinense to NaCl and Na2CO3

The seedlings of A.chinense were stressed by NaCl(0-700 mmol/L) and Na_2CO_3(0-200 mmol/L).Many physiological indices were determined: relative growth rate,relative water content,root activity,cytoplasm osmosis,concentrations of chlorophyll and nitrogen.The results showed that the seedlings of(A.chinense) were alive only when the concentrations of salts were lower than 600 NaCl and 175 mmol/L Na_2CO_3.The growth of A.chinense was obviously depressed and with increasing salt concentrations,tiller rate,rhizome number,RGR,RWC,and concentrations of chlorophyll and nitrogen decreased.The effects of Na_2CO_3 on the growth of A.chinense were more severe than those of NaCl.The permeability of plasmalemma was increased and the function eventually destroyed by both NaCl and Na_2CO_3 stress.The extravasation rates of potassium and electrolyte increased with increasing salt stress.The concentrations of TTC,(the index of root activity),were decreased with increasing salt stress and were almost zero when the concentration of Na~ exceeded 200 mmol/L.The effects of Na_2CO_3 were different and more severe than those of NaCl.