不同盐浓度的混合盐对羊草苗的胁迫效应

STRESS EFFECTS OF MIXED SALTS WITH VARIOUS SALINITIES ON THE SEEDLINGS OF ANEURO LEPIDIUM CHINENSE 

用５０～３５０ｍｍｏｌ／Ｌ含有不同比例的ＮａＣｌ、Ｎａ２ＳＯ４、ＮａＨＣＯ３和Ｎａ２ＣＯ３等４种盐成分的３０种混合盐对羊草（Ａｎｅｕｒｏｌｅｐｉｄｉｕｍｃｈｉｎｅｎｓｅ（Ｔｒｉｎ．）Ｋｉｔａｇ．）苗进行盐碱混合胁迫处理。结果表明：相对生长率、Ｋ和Ｎａ含量、脯氨酸积累量及叶片电解质外渗率等胁变反应均随盐浓度增大以及碱性盐比例增高而加剧。而且碱性盐所造成的高ｐＨ的致胁变效应与盐浓度关系极大，浓度低时作用较小，随浓度增大其作用加剧。在含有碱性盐的混合盐胁迫中，包含有盐胁迫和碱胁迫两种作用。以总盐浓度代表盐胁强，缓冲量代表碱胁强。在碱胁强较弱时胁变主要受盐浓度影响。

Seedlings of Aneurolepidium chinense (Trin.) Kitag. were subjected to stress with 30 kinds of 50 to 350 mmol/L of salt mixture which were composed of NaCl, NaHCO 3,Na 2SO 4,and Na 2CO 3 in various proportion. The results showed that all the responded strains, such as changes in the relative growth rate (RGR), K + and Na + contents, content of proline accumulation, and leave electrolyte leakage rate, were aggravated with the increasing salt concentrations and the proportion of the basic salts. The strain reaction from high pH caused by the basic salt was closely related to salinity. The high pH reaction was weaker when the salinity was lower and became progressively stronger intensely with the increasing salinity. The results indicated that there were actually two stresses, the salt and the alkaline stress in the mixed salt stress. It was reasonable to consider the total salt concentration as the strength value of salt stress and the buffer capacity as the strength value of alkaline stress. When the alkaline stress was weak, the strain effect was mainly associated with the total salt concentration, but the buffer capacity became the dominant factor effecting strain with the increasing alkaline stress.