【摘要】 本文以6个大丽花（Dahlia pinnata Cav.）品种为材料，研究高温胁迫处理（40℃/35℃，14 h昼/10 h夜）2 d对其形态和生理指标的影响，应用相关性分析、主成分分析和隶属函数法计算耐热性综合评价值D，并用逐步回归分析法筛选鉴定大丽花耐热性指标。结果显示：（1）高温胁迫后，叶片中F_v/F_m值和叶绿素含量均下降；抗坏血酸和还原型谷胱甘肽含量在叶片中上升，在茎中下降；可溶性糖和可溶性蛋白含量在叶片和茎中均下降；总酚含量在叶片中显著上升，在茎中显著下降；花青素含量在叶片和茎中均上升。（2）基于耐热性综合评价值D,6个品种中，‘SLGZ’耐热性较强；‘KEW’、‘QKL’和‘YH-C11’耐热性中等；‘AGR-C1’和‘YY-C5’耐热性弱。（3）回归分析结果表明，叶片的半致死温度和叶绿素含量、茎的可溶性蛋白和抗坏血酸含量、热害指数可作为鉴定大丽花耐热性的指标。更多还原

【Abstract】 Six cultivars of Dahlia pinnata Cav. were used to investigate the effects of high-temperature stress(40℃/35℃, 14 h/10 h(day/night), 2 d) on morphological and physiological indices. Correlation analysis, principal component analysis, and membership function analysis were applied to calculate the comprehensive evaluation value D for heat resistance and stepwise regression analysis was used to screen indicators of heat tolerance. Results showed:(1) After high-temperature stress, the F_v/F_m value and chlorophyll content decreased in leaves. Ascorbic acid and reduced glutathione contents increased in leaves and decreased in stems, while soluble sugar and soluble protein contents decreased in both leaves and stems. Total phenol content increased significantly in leaves and decreased significantly in stems, while anthocyanin content increased in leaves and stems.(2) According to the comprehensive evaluation value D for heat resistance, among the six varieties, ‘SLGZ’ showed the strongest heat resistance, ‘KEW’, ‘QKL’, and ‘YH-C11 showed medium heat resistance, and ‘AGR-C1’ and ‘YY-C5’ showed the weakest heat resistance.(3) Regression analysis indicated that semi-lethal temperature and chlorophyll content of leaves, soluble protein and ascorbic acid content of stems, and the heat damage index could be used as indicators of heat tolerance in dahlias.更多还原