摘要
在高温与盐胁迫下，红萍体内电解质发生外渗，并随着红萍组织受伤害程度的增强而加剧。在４５℃高温胁迫下，电导值Ｂ与茎尖死亡率呈显著直线相关。比较了不同萍种在同一逆境下的茎尖死亡率与电解质相对渗出量Ｌ（％），认为Ｌ值的大小能客观地反映萍种的抗热性。在盐胁迫下，红萍Ｌ值随盐浓度的升高而升高，其大小与萍种的耐盐性表现一致。在３９℃高温胁迫下，红萍体内游离脯氨酸无显著累积，比常温提高１０℃的情况下，体内脯氨酸含量无规律性差异，但在４５℃的高温胁迫下，游离脯氨酸却随胁迫时间的延长而呈下降趋势。在盐胁迫下，脯氨酸含量随着盐浓度升高而迅速累积，累积速度越快的萍种，对盐浓度的耐受性就越差。
Both high temperature and salt stress resulted in electrolyte leakage from Azolla fronds,and the amount of the leakage was increased with the increase of damaged degree. Under 45℃ high tem-perature,the leakage conductivity showed linar regression with the mortality of Azolla stem apex. In comparison of mortality of stem apex and relative leaking rate L(%)among different Azolla species treated at 41.5℃ in closed and at 45℃ in open water bath,L(%)could reflect the heat tolerance of tested Azolla species. Similarly,under the salt stress,electrolyte leakage accelerated with the incresae of salt concentration,and L(%)also has the same trend to reflect salt tolerance among Azolla species. Under 39℃C,Azolla has no significant accumulation of free proline which also showed on regu-lar variation within the temperature range which is 10℃ higher than the normal.However,in 45℃ water bath,free proline decreased with the prolonging of the treating time. Under the salt stress,free proline accumulated with the increase of salt content,and the more rapid accumulation of one species implied the more suscepitible of the species to salt stress.
关键词
红萍
高温胁迫
盐胁迫
脯氨酸
Azolla
High temperature stress
Salt stress
Electrolyte leakage
Free proline
