镧对西葫芦幼苗模拟酸雨胁迫的缓解效应

摘要

Using Cucurbita pepo as the experimental material,the alleviative effects of foliar surface spraying for LaCl3（12 mg/L） on seedling growth and three physiological indexes of C.pepo were investigated under some simulated acid rain（SAR） stresses.Results show that the damage effects of SAR on C.pepo seedlings are alleviated by the LaCl3 treatment.The fresh weights of the seedlings treated with LaCl3 solutions of pH 3.5 and pH 3.0 are significantly higher than those of the treatments only with SAR,and are equivalent to 94.7% and 78.6% of the control level（pH 6.5）.However,no significant differences are observed between the treatment with other SAR＋LaCl3 solution and the treatment only with SAR.The chlorophyll and dissolved protein contents follow the trend of the seedling fresh weight,and the indexes treated with pH 3.0 and pH 3.5 SAR＋LaCl3 solutions are higher significantly than that treated only with SAR,but the differences of pH 3.0 are slightly greater than those of pH 3.5.Compared with the control,the dissolved protein content treated with pH 3.5＋LaCl3 solution is the highest.The proline content increase consistently with the pH value,and improved by the LaCl3 treatment.The proline contents treated with pH 3.5 and pH 3.0 SAR＋LaCl3 solution are higher significantly than that treated only with SAR.Therefore,the alleviative effects of LaCl3 on middle SAR stresses for C.pepo seedling are significant.%以西葫芦为材料,研究模拟酸雨胁迫下适量镧（La）对幼苗生长及叶绿素、可溶性蛋白和脯氨酸含量的影响。结果显示,镧处理对酸雨胁迫有一定的缓解作用。在pH 3.5和3.0时,幼苗鲜重均显著高于模拟酸雨组,并恢复到对照的94.7%和78.6%;但在其他胁迫强度下,镧处理的缓解效应不显著。叶绿素和可溶性蛋白的含量变化与幼苗鲜重类似,在pH 3.0时镧处理的缓解效应最显著;pH 3.5时镧处理的可溶性蛋白含量超过对照。脯氨酸含量呈现持续上升趋势,且镧处理可增加脯氨酸的积累,但只有pH 3.5和3.0时显著高于模拟酸雨