油菜素内酯对黄瓜苗期叶片光合机构调节作用的研究

 0.1 mg· L ^{- 1}油菜素内酯( EBR) 处理黄瓜叶片后能显著提高净光合速率( Pn) , 其效应可持续一周。EBR 处理对叶片叶绿素含量和气孔限制值(l) 无明显影响, 但显著提高了表观量子效率(AQY) 、羧化效率(CE) 、Rubisco最大羧化速率(V_c,max ) 和RuBP最大再生速率( J_max ) 。EBR还通过增加PSⅡ反应中心开放程度( qP) 从而提高PSⅡ光合电子传递量子效率(Φ_PSⅡ) , 但不影响天线色素的光能转化效率( Fv'/Fm') 。

Role of Brassinosteroids in the Regulation of Photosynthetic Apparatus in Cucumber Leaves

Spray with 0.1 mg·L ^{- 1} 24-epibrassinolide ( EBR) significantly up-regulated the net photosynthetic rates of cucumber (Cucumis sativus) seedlings and the effect lasted for 1 week. EBR had no effect on chlorophyll content and stomatal limitation value (l) , but significantly increased apparent quantum yield(AQY) , carboxylation efficiency (CE) , the maximum carboxylation rate of Rubisco (V_c,max ) and the maximum rate of RuBP regeneration (J_max ). EBR treatment also increased the p roportion of‘open’PSⅡ reaction centers ( qP) , thereby resulting in an increased quantum yield of PSII electron transport (Φ_PSⅡ ) , but had little effects on the maximal photochemical efficiency of PSⅡ ( Fv/Fm) , and efficiency of energy capture by open PSⅡ reaction centres ( Fv’ /Fm’).