短期高温胁迫对高产小麦品系灌浆后期旗叶光系统Ⅱ功能的影响

Effects of short-term high temperature stress on flag leaf photosystem Ⅱ functions of high-yielding wheat at late grain-filling stage.

以叶绿素快相荧光动力学曲线(OJIP)为探针,探讨了高温胁迫对高产小麦品系01-35灌浆后期光系统Ⅱ(PSⅡ)功能的影响.结果表明,在37℃～43℃范围内,随温度升高QA还原程度和还原速率增大,至43℃时分别比室温下增加了23.89%和24.09%,表明QA→QB的电子传递受到抑制;43℃时PSⅡ的电子受体库降至室温下的47.4%,表明高温胁迫伤害了PSⅡ受体库;而PSⅡ供体侧未受到影响.当温度达到46℃时,QA还原程度和还原速率分别比室温下增加了13.95%和20.48%,但比43℃时显著下降,而PSⅡ电子受体库与43℃时相比无显著变化,表明46℃时PSⅡ供体侧受到伤害.与对照品种鲁麦14相比,高温胁迫下高产小麦的捕光色素复合体仍能捕获较多的光能,而且将捕获的光能更多的用于电子传递,表明高产小麦的捕光色素复合体及电子传递体耐受高温的能力较强,能够维持较高的电子传递能力.

By using fast OJIP chlorophyll a （ Chl a） fluorescence transients, this paper studied the effects of short-term high temperature stress on the flag leaf photosystem Ⅱ （PS Ⅱ ） functions of high-yielding winter wheat cuhivar 01-35 at its late grain filling stage. The results showed that with the temperature raised from 37 ℃ to 43 ℃, the extent and velocity of QA reduction enhanced gradually, being 23.89% and 24. 09% higher at 43 ℃ than at room temperature, respectively, which suggested that the electron transport from QA to QB was inhibited. The electron acceptor pool of PSⅡ including QA, QB and PQ at 43℃decreased to 47.4% of that at room temperature, indicating its being damaged. The electron donor side of PSⅡ was not damaged from 37℃ to 43℃. When temperature raised to 4℃ , the extent and velocity of QA reduction were 13.95% and 20.48% higher than those at room temperature, respectively, but decreased obviously, compared with those at 43℃. In contrast, the electron acceptor pool of PS Ⅱ at 46℃ had no obvious change, compared with that at 43℃, indicating that the electron donor side of PS Ⅱ at 46℃ was damaged. Comparing with cuhivar Lumai 14, the light harvesting complex （ LHC Ⅱ ） of high-yielding wheat cuhivar 01-35 could harvest more sun energy, and distributed more absorbed energy into electron transport, suggesting that the LHCⅡ of cuhivar 01-35 could endure a certain higher temperature, and maintain higher electron transport capacity.