Abstract: [Objective] This study aims to investigate the differences of leaf chlorophyll fluorescence characteristic parameters between different genotypes of cotton under different temperatures and to provide a theoretical basis to screen suitable indexes for evaluating high temperature-tolerance of cotton varieties.[Method]Chlorophyll fluorescence characteristic parameters in leaves of cotton seedlings of four different genotypes(13-1 strain,Xinhai 24,13-1×Xinhai 24 hybrid,13-1×Xinhai 14 hybrid)were determined by rapid fluorescence detector(Handy PEA-100)under 25℃,30℃,35℃,40℃,45℃ and 48℃ respectively.[Result]The performance index of PIABS,maximum photochemical Fv/Fm and electron transfer yield φEo increased at first and decreased subsequently as the temperature increased,the heat dissipation DIO/CSO,initial fluorescence FO was on the contrary.PIABS performance index between the four different genotypes of strains was extremely significant at 40℃,and it could more accurately reflect photosynthetic status than Fv/Fm.[Conclusion]Using the method of subordinate function to analyze the four different genotypes,it is found that 13-1×Xinhai 24(hybrid)has the highest subordinate function value,and we believe that it belongs to heat resistant strains.

摘要： [目的]在不同温度条件下,研究不同基因型棉花叶片叶绿素荧光特性指标的变化,为耐高温棉花品种的筛选提供理论依据.[方法]分别在25、30、35、40、45和48℃的恒温培养箱处理不同基因型棉花13-1品系、新海24号、13-1×新海24号(杂交种)、13-1×新海14号(杂交种),利用快速荧光测定仪(Handy PEA-100)测定不同基因型棉花叶片荧光特性主要参数.[结果]随着温度不断升高,性能指数PIABS、最大光化学Fv/Fm、电子传递产额φEo表现为先升高后降低,而热耗散DIO/CSO、初始荧光FO则先降低后升高;性能指数PIABS在40℃时4个不同棉花基因型棉花品系呈极显著,比Fv/Fm更准确地反映光合状况.[结论]利用隶属函数法分析4种不同基因型棉花品种(系),其中13-1×新海24号隶属函数值最高,属于耐热品系.