高温胁迫对德钦紫花苜蓿形态指标和生理特性的影响

Effects of High Temperature Stress on Morphological Indexes And Physiological Characteristics of Deqin Alfalfa

为了探明高温胁迫对德钦紫花苜蓿(秋眠级1.2)生长发育的影响,研究以不同耐热性的紫花苜蓿品种——阿尔冈金(秋眠级2)和赛迪10(秋眠级9)为对照材料,进行高温胁迫处理,胁迫温度为35℃/30℃(白天/黑夜),对照温度为25℃/20℃(白天/黑夜),胁迫处理105 d,对供试材料的形态和生理指标进行分析。结果表明:在高温胁迫下,德钦紫花苜蓿的分枝数累积增长率最高(8 900%),植株能保持较高的增长速度;主茎长度减少幅度最小(-9.45%),徒长程度较轻;相对含水量累积增长率变幅小(8.92%),含水量相对稳定;相对电导率的增长率最小(862.82%),细胞膜受高温危害程度较轻。综合各指标分析结果,德钦紫花苜蓿具有较好高温耐受性。高温胁迫后紫花苜蓿植株主茎长度变短、分枝数增加和含水量相对稳定,这些指标可否作为鉴定植物的耐热性的指标有待于进一步研究。

In order to study the effect of high temperature stress on growth and development of Deqin （FD1.2） Alfalfa,different heat-resistance alfalfa：Algongum （FD2） and Saidi 10 （FD9） were taken as comparative materials treated under high temperature,it was set stress temperature as 35℃/30℃ （day/night）,contrast temperature as 25℃/20℃ （day/night）,and the study were stress a total of 105 days for morphological and physiological characteristics.The results showed that under high temperature stress cumulative increase rate of branch number of Deqin was the highest （8 900%）,the plant could maintain higher increase rate; reduce the amplitude of main stem length was the minimum （-9.45 %） and its vain grow was in a lesser degree ; the amplitude of cumulative increase rate of Deqin＇s relative water content was little （8.92%） and water content was relatively stable ; the increase rate of relative conductivity was the least （862.82%）,so cytomembrane damage under high temperature to a lesser degree.Based on the analysis of various indicators,Deqin alfalfa had a better heat resistance.The main stem length became shorter,branch number increased and water content was relatively stable after high temperature stress,and whether these indexes could be used for heat resistance identification of plant index or not needs to make a further study.