不同品种辣椒幼苗光合特性及弱光耐受性的差异

 在不同弱光处理条件下, 利用L I26400型便携式光合仪研究了弱光对4个辣椒品种幼苗光响应曲线、CO₂ 响应曲线等光合特性的影响, 结果表明弱光下辣椒的光补偿点(LCP) 、光饱和点(LSP) 、光饱和光合速率、CO₂ 补偿点(CCP) 、CO₂ 饱和点(CSP) 、暗呼吸速率(Rd ) 、羧化效率(CE) 、RuBP羧化酶活性、RuBP最大再生速率均下降, 表观量子效率(AQY) 上升, 并且弱光下辣椒净光合速率( Pn)的下降是RuBP羧化限制和再生限制的共同结果。另外随光照的减弱, 辣椒叶片叶绿素(Chl. ) 含量上升,叶绿素a /b比值(Chl. a /b) 和比叶重( SLM) 下降。弱光下LCP和Rd 相对较低、AQY和CE较高的辣椒品种可能具有耐弱光的优势。

Differences of Photosynthetic Characteristics and Low Light-tolerance in Seedlings of Four Pepper Cultivars

The effect on photosynthesis-light response curve and CO_2 response curve of the seedlings of four pepper cultivars treated under the different low light intensities were investigated using a LI-6400 portable photosynthesis system. The results showed that under shading conditions, light compensation point(LCP), light saturation point(LSP), CO_2 compensation point(CCP), CO_2 saturation point(CSP), photosynthetic rate at light saturation point, dark respiration rate(R_d), carboxylation efficiency(CE), RuBPCase activity, and maximum RuBP regeneration rate decreased, but apparent quantum yield(AQY) increased. The decrease of net photosynthetic rate under low light intensity was considered as a result of RuBP carboxylation restriction and regeneration restriction. In addition, as the light intensity decreased, the chlorophyll contents(Chl.) increased, but the chlorophyll a/b ratio(Chl.a/b) and specific leaf mass(SLM) declined. Cultivars relatively lower LCP and Rd, higher AQY and CE under low light intensity with may possess potential low light-tolerance.