中文摘要：

采用叶绿素荧光分析方法,以高原春小麦（‘互助红’、‘互麦12’和‘互麦13’）为材料,研究了孕穗期旗叶的PSⅡ光化学效率以及光化学和非光化学猝灭的光响应特性。结果显示：（1）3个春小麦品种旗叶的光合色素有差异,最大光化学效率（Fv/Fm）无显著差异。（2）随着光强增加,3个品种旗叶有效光化学效率（Fv′/Fm′）、实际光化学效率（ΦPSⅡ）、光化学猝灭系数（qP）、PSⅡ反应中心开放比率（qL）均呈降低趋势;低光强范围内,叶片Fv′/Fm′、ΦPSⅡ、qP、qL值均依次按‘互麦12’〉‘互助红’〉‘互麦13’的顺序降低;中高光强范围内,3个品种的Fv′/Fm′趋于一致,而‘互助红’的ΦPSⅡ、qP、qL较其他两个品种略高。（3）随着光强增加,各品种非光化学猝灭系数（NPQ）、表观电子传递速率（ETR）、调节性能量耗散量子产量（ΦNPQ）、非调节性能量耗散量子产量（ΦNO）均呈升高趋势;中低光强范围内,NPQ、ΦNPQ值均依‘互麦13’〉‘互助红’〉‘互麦12’的顺序降低,而‘互助红’和‘互麦12’的ETR变化较为一致且‘互麦13’的最低;中高光强范围内,NPQ、ΦNPQ值均依次按‘互助红’〉‘互麦13’〉‘互麦12’的顺序降低,而ETR值按‘互助红’〉‘互麦12’〉‘互麦13’的顺序降低;在整个光强变化过程中,ΦNO表现为按‘互麦13’〉‘互麦12’〉‘互助红’的顺序依次降低。研究认为,3个高原春小麦品种中‘互助红’最适应高光强环境;‘互麦12’光能利用能力强于‘互麦13’,但略弱于‘互助红’;‘互麦13’对光强变化较为敏感,热耗散能力略强于‘互麦12’,在低光环境下有较高的热耗散能力。

英文摘要：

Based on the analysis of chlorophyll fluorescence parameters,we investigated the light responses of PSⅡ photochemical efficiency,photochemical and non-photochemical quenching processes in flag leaves of booting stage with three local varieties of spring wheat（Triticum aestivum L.）.The results showed that：（1）There was a difference of chlorophyll（Chl）content among three local wheat varieties,but themaximum quantum photochemistry efficiency of PSⅡ（Fv/Fm）had no significant difference among them.（2）As the increase of light intensity,the PSⅡ maximal photochemical efficiency（Fv′/Fm′）,PSⅡ actual photochemical efficiency（ΦPSⅡ）,PSⅡ photochemical quenching coefficient（qP）and the fraction of PSⅡ reaction centers that are opened（qL）all exhibited a decreased tendency.Under low light intensity,Fv′/Fm′,ΦPSⅡ,qPand qLof wheat flag leaves decreased from ‘Humai 12＇through ‘Huzhuhong＇to ‘Humai13＇.Under the middle and high light intensity,changes of Fv′/Fm′values in three varieties tended consistent,but the values ofΦPSⅡ,qPand qLin‘Huzhuhong＇were slightly higher than that of other two.（3）The values of PSⅡ non-photochemical quenching coefficient（NPQ）,apparent electron transfer efficiency（ETR）,the quantum yield of quenching due to light-induced processes and non-light-induced processes（ΦNPQandΦNO）tended to increase with the increasing of light intensity.Under low light intensity,the NPQ andΦNPQdecreased from ‘Humai 13＇through ‘Huzhuhong＇to ‘Humai 12＇,changes of ETRin ‘Huzhuhong＇and‘Humai 12＇tended consistent,value of ETRin‘Humai 13＇was the lowest among three varieties.Under the middle and high light intensity,NPQandΦNPQdecreased from ‘Huzhuhong＇through‘Humai 13＇to‘Humai 12＇,the ETRshowed a decreased tendency from ‘Huzhuhong＇through‘Humai 12＇to‘Humai 13＇.During the whole changes in light intensity,ΦNOdecreased from ‘Humai 13＇through‘Humai12＇to‘Huzhuhong＇.The study sugges