耐热小麦生理特征分析

Analysis of Physiological Characteristics of Heat Resistant Wheat

为了确定耐热品种抗性提高的生理机制,筛选简单易行的耐热评价指标。2017年秋-2019年夏在河北藁城利用温室增温和人工气候室增温,研究了不同增温处理对冬小麦产量和生理指标的影响。结果表明,冀麦418高温条件下千粒质量、产量和经济系数降低,但与衡4444和山农28比较,降幅较小;并且冀麦418产量热感指数明显低于1,属于耐热性品种。通过相关性分析表明,旗叶SPAD值、相对含水量、光合速率、冠温与产量显著相关,旗叶SPAD值、冠温与产量热感指数也呈显著相关,综合丰产性和耐热性,这些指标可作为耐热品种筛选的参考指标。由此得出耐热品种生理特点为:高温下旗叶光合速率、SPAD值、相对含水量和生育后期荧光参数QY和Fv/Fm降幅较小,且冠温较低,生育后期仍可维持较高的叶片生理活性。

The purposes of this study were to determine the physiological mechanism of resistance improvement of heat-resistant varieties and to select simple heat-resistant evaluation indexes.Warming experiment was carried out in Gaocheng of Hebei Province from Autumn 2017 to Summer 2019 to study the effects of different warming treatments on the yield and physiological indexes of winter wheat under greenhouse warming and artificial climate chamber warming condition.The results showed that the thousand grain weight,grain yield and economic coefficient of Jimai 418 decreased under high temperature,but the reduce extent was smaller than that of Heng 4444 and Shannong 28,and the heat sensitive index of yield of Jimai 418 was significantly lower than 1,which belonged to heat resistant variety.The correlation analysis showed that the SPAD value,relative water content,photosynthetic rate and canopy temperature of flag leaf were significantly related to yield,the SPAD value and canopy temperature of flag leaf were also significantly correlated with the yield heat sensitivity index.The comprehensive high yield and heat tolerance which these indexes can be used as the reference index for heat-resistant variety selection.The physiological characteristics of heat resistant varieties were as follows:photosynthetic rate,SPAD value,relative water content and fluorescence parameters QY and Fv/Fm of flag leaf decreased slightly at high temperature,and the canopy temperature was lower as well,and the physiological activity of flag leaf was still high at late growth stage.