论文部分内容阅读
以平邑甜茶盆栽苗为试材,通过同步测定叶片的叶绿素瞬时荧光、延迟荧光及820 nm光反射,研究了干旱胁迫对两个光系统(PSII和PSI)和光合电子传递链的伤害,以及根部施硅对平邑甜茶光合功能的改善作用。结果显示,中度干旱胁迫(40%RSWC)下,PSII原初光化学反应的最大量子产额(TRo/ABS),PSII捕获的电子从Q_A传递给Q_B的概率(ETolTRo),远红光下测定的MR/MRo最大下降振幅(△MR_(FR))下降,而PSII单位反应中心吸收的光能(ABSrRC)上升,表明干旱导致整个光合电子传递链(包括PSII和PSI)均出现不同程度的伤害。干旱胁迫下,硅处理的MR/MRo下降斜率(V_(PSI))、非光化学猝灭(NPQ)显著大于对照,延迟荧光的I_1和I_2点比值(I_2/I_1)低于对照,表明硅处理可提高干旱胁迫下PSI的活性,提高环PSI的电子传递和PSII天线热耗散的能力。总之,硅处理显著缓解了干旱胁迫对PSII和PSI的伤害程度,根部施硅通过提高平邑甜茶幼苗PSI和PSII的活性,促进PSI环式电子传递,提高了平邑甜茶幼苗的抗旱性。
In this study, the photosynthetic electron transport chain damage of PS2 and PSI and photosynthetic electron transport chain under drought stress were studied by simultaneous determination of leaf chlorophyll fluorescence, delayed fluorescence and 820 nm light reflectance. Improvement of Photosynthetic Function of Malus hupehensis by Applying Silicon at Roots. The results showed that under moderate drought stress (40% RSWC), the maximum quantum yield of primary photochemical reaction of PSII (TRo / ABS), the probability of electron transfer from Q_A to Q_B (ETolTRo) The decrease of maximum MR / MRo amplitude (△ MR - FR) decreased and the absorption of light energy (ABSrRC) increased in the PSII unit reaction center, indicating that drought caused different degrees of damage to the whole photosynthetic electron transport chain (including PSII and PSI). Under drought stress, the slope of MR / MRo decline (V PSI) and non-photochemical quenching (NPQ) of silicon treatment were significantly higher than those of control, and the ratio of I_1 / I_2 point of delayed fluorescence (I_2 / I_1) It can increase the activity of PSI under drought stress and improve the ability of electron transfer of PSI and heat dissipation of PSII antenna. In conclusion, silicon treatment significantly alleviated the damage of PSII and PSI under drought stress. The root application of silicon enhanced the cyclic electron transfer of PSI and the drought resistance of P. euphratica seedlings by increasing the PSI and PSII activity of P. euphratica seedlings.