【摘要】 利用叶绿素荧光技术,研究高温胁迫下不同热敏感性小麦品种光化学活性和能量分配的差异。结果表明:在37.5℃以上的高温胁迫下,与热敏感的小麦品种‘Torysa’相比,耐热品种‘Ilona’通过保持高的PSII最大光化学效率(φPo)、捕获的能量向电子传递链传递的效率(ψo)以及用于电子传递的量子产额(φEo)使更多的能量被反应中心捕获并进入电子传递链,而热敏感品种‘Torysa’中较高的用于热耗散的量子比率(φDo)表明其更多的能量用于热耗散,从而使得‘Ilona’中光化学反应可以利用的能量多于‘Tor ysa’。与此同时,‘Ilona’还有相对更多的PSI参与环式电子传递,耗散多余的能量,从而减少活性氧的产生。因而在高温胁迫下,‘Ilona’能够维持较高的光化学效率,降低光抑制,具有更好的耐热性。更多还原

【Abstract】 The photochemical activity and energy distribution on wheat varieties with different heat-sensitivity were tested by chlorophyll a fl uorescence measurement under high temperature stress. The results showed that under temperature higher than 37.5 ℃, ‘Ilona’(thermo-tolerant variety) maintained h igher level of maximum photochemical effi ciency of PSII(φPo), effi ciency with which a trapped exciton can move an electron into the electron transport chain(ψo) and the ratio of electron transport fl ux(φEo) to distribute more energy trapped by reaction center into electron transport chain, while ‘Torysa’(thermo-sensitive variety) distributed more energy to dissipation by a higher quantum yield of energy dissipation(φDo). Compared to ‘Torysa’, ‘Ilona’ had more energy available for photochemistry. Meanwhile, ‘Ilona’ had more PSI involved in the cyclic electron fl ow and dissipating excess excitation energy. Therefore, under high temperature stress, thermos-tolerant variety ‘Ilona’ maintain higher photochemical activi ty of PSII, and lower level of photoinhibition than thermos-sensitive variety ‘Torysa’, and thus showed higher thermotolerence.更多还原