不同外源物质对高温胁迫下金莲花幼苗生理生化的影响

Effects of Different Exogenous Substances on Physiology and Biochemistry of Trollius chinensis Seedlings under Heat Stress

以当年生金莲花幼苗为试验材料,采用叶面喷施的方法,研究CTS(壳聚糖),CaCl_2(氯化钙)和SA(水杨酸)三种外源物质最佳浓度的二元及三元复配对高温胁迫下金莲花幼苗生理及叶绿素荧光参数的影响,为提高金莲花的耐热性提供理论依据。结果表明:60 mg/L CTS+138 mg/L SA复配处理缓解金莲花幼苗高温伤害的效果最好,显著降低了金莲花幼苗的热害指数、相对电导率和丙二醛(MDA)含量,提高了游离脯氨酸、可溶性蛋白、可溶性糖含量以及超氧化物歧化酶(SOD)活性,缓解了叶绿素降解和高温对PSⅡ反应中心的伤害,从而提高其耐热性,为解决金莲花幼苗在低海拔地区越夏问题提供技术支持。同时,通过热害指数和其他指标的相关性分析(P<0.05),筛选出相对电导率、F_(o)、ABS/RC、MDA含量、叶绿素总量、Pro、可溶性糖、F_(v)/F_(m)、F_(v)/F_(o)和ETo/RC等作为金莲花耐热性的评价指标。本研究为提高金莲花的耐热性及引种到北方低海拔地区栽培提供理论和技术指导。

The influence of binary and ternary combinations of CTS(chitosan),CaCl2(calcium chloride)and SA(salicylic acid)on the physiological and chlorophyll fluorescence parameters of Trollius chinensis seedlings under high temperature stress were studied by foliar spraying method.This study provided a theoretical basis for improving the heat resistance of T.chinensis.The results showed that:the combined treatment of 60 mg/L CTS+138 mg/L SA had the best effect on alleviating the high temperature injury of T.chinensis seedlings,significantly reduced the heat injury index,relative conductivity and MDA content of T.chinensis seedlings,increased the contents of free proline,soluble protein,soluble sugar and superoxide dismutase(SOD)activity.It can alleviate the damage of chlorophyll degradation and high temperature to PSⅡreaction center,so as to improve its heat resistance,and provide technical support for solving the problem of overwintering of T.chinensis seedlings at low altitude.At the same time,the relative conductivity,Fo,ABS/RC,MDA content,total chlorophylls,Pro,soluble sugar,F_(v)/F_(m),F_(v)/F_(o)and ETo/RC were selected as the evaluation indexes of heat tolerance of T.chinensis by correlation analysis between heat injury index and other indexes(P<0.05).This study provides theoretical and technical guidance for improving the heat resistance of T.chinensis and introducing it to low altitude areas in northern China for cultivation.