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研究了盐和强光双重胁迫以及在弱光下恢复对冬小麦 (TriticumaestivumL .)光合功能的影响。结果表明 ,单纯用低浓度盐 (2 0 0mmol/LNaCl)胁迫时 ,对反映PSⅡ光合功能的Fv/Fo、Fv/Fm和qP等参数没有什么影响 ,但已十分明显地抑制光合碳同化能力 ,而高盐 (4 0 0mmol/LNaCl)胁迫损伤PSⅡ功能 ,从而加剧对碳同化功能的抑制 ,说明光合作用对不同盐浓度的响应不同。研究结果还表明 ,盐胁迫能加剧强光对光合功能的损伤 ,使之受到更加严重的光抑制。在低盐浓度下 ,光抑制初期形成的QB_非还原性PSⅡ反应中心 ,在随后的光抑制进程和弱光下恢复期间 ,能有效的被用来合成有活性的PSⅡ和修复可逆性失活的PSⅡ反应中心。而高盐和强光双重胁迫使PSⅡ遭受严重破坏 ,QB_非还原性PSⅡ反应中心只有在光抑制初期可部分地用于修复可逆性失活的PSⅡ ,随着光抑制的进程 ,它们不能用于合成有活性PSⅡ和修复受严重破坏的PSⅡ ,结果导致它们的含量在弱光下恢复时继续增加
The effects of double salt and light stresses and their restoration on photosynthetic function of winter wheat (Triticum aestivum L.) Under low light were studied. The results showed that the Fv / Fo, Fv / Fm and qP parameters which reflect the photosynthetic function of PSⅡhad no effect on the photosynthetic function of PS Ⅱ, but inhibited the photosynthetic carbon assimilation obviously, However, high salt (400 mmol / L NaCl) could damage the function of PS Ⅱ and aggravate the inhibition of carbon assimilation, indicating that photosynthesis responded differently to different salt concentrations. The results also show that salt stress can aggravate the damage of photosynthetic function under intense light and make it suffer more severe photoinhibition. At low salt concentrations, the QB-nonreducing PSⅡ reaction formed initially by photoinhibition can be effectively used to synthesize active PSⅡ and repair reversible inactivation during subsequent photoinhibition processes and low light recovery PS Ⅱ reaction center. However, PSⅡ was severely damaged by high salt and light stress. QB non-reducing PSⅡ reaction center could partly be used to repair reversibly inactivated PSⅡin the early stage of photoinhibition. With the progress of photoinhibition, they could not be used In the synthesis of active PSII and the repair of severely damaged PSII, as a result of their content in low light recovery continued to increase