不同品种辣椒幼苗光合特性及弱光耐受性的差异

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

在不同弱光处理条件下,利用LI6400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。

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.