安徽农业科学

为探究沙参幼苗对中性盐胁迫的生理响应，测定其在NaCl及NaCl∶Na_2SO₄(摩尔比9∶1)混合盐处理下的叶片生理特性，以期为沙参在盐碱生境中的有效利用提供理论依据。结果表明，幼苗死亡的临界浓度分别为125 mmol/L NaCl及100 mmol/L的混合盐。除致死浓度外，沙参幼苗的各项生理指标随着盐溶液的浓度呈规律性变化。随着盐胁迫程度的不断增加，沙参幼苗侧根数在盐浓度为50 mmol/L时最多；叶绿素含量整体呈下降趋势，在NaCl溶液浓度为100 mmol/L时达到最低值，混合中性盐溶液浓度为75 mmol/L时达到最低值。在2种处理盐浓度为50 mmol/L时，POD与CAT活性均达到最高。盐胁迫虽能影响沙参幼苗的生长发育和光合作用，但沙参幼苗对低浓度中性盐有一定的抵抗能力。

The physiological characteristics of leaves of Adenophora stricta seedlings were determined under different neutral salt stress conditions(NaCl alone and a mixed salt of NaCl and Na_2SO₄ with a molar ratio of 9∶ 1),aiming to provide a theoretical basis for the effective utilization of Adenophora stricta in saline-alkali habitats.The results showed that 125 mmol/L NaCl and 100 mmol/L mixed neutral salts were the critical concentrations leading to seedling death.Besides the lethal concentration, various physiological indexes of Adenophora stricta seedlings varied with the concentration of salt solution.With the increasing degree of salt stress, the number of lateral roots of Adenophora stricta seedlings was the highest at a salt concentration of 50 mmol/L.The chlorophyll content of Adenophora stricta showed an overall downward trend, reaching the lowest value at a NaCl concentration of 100 mmol/L,and at a mixed neutral salt concentration of 75 mmol/L.At a concentration of 50 mmol/L for both salt treatments, the activities of POD and CAT both reached the maximum.These results indicate that although salt stress can affect the growth, development and photosynthesis of Adenophora stricta seedlings, the seedlings have a certain resistance to low concentrations of neutral salts.