海芋、山茶夏季温室条件下的光合特性

 研究了高温对海芋(Alocasia odora C. Koch. ) 、山茶(Camellia japonica L. ) 净光合速率(Pn)的影响。结果表明: 在高于最适温度时二者Pn 下降, 但海芋下降幅度小, 即使完全消除气孔限制, 也未能阻止Pn 的降低; 在高于最适温度条件下的羧化效率和RuBP 最大再生速率下降, 且后者下降更严重; 高温下光呼吸增加。因此我们认为: 1) 海芋可能对高温有较好的适应性, 山茶对高温很敏感。2) 高温下Pn下降主要是非气孔限制造成的, RuBP 最大再生速率的降低可能是主要限制因素。3) 光呼吸可能也是高温下Pn 降低的原因之一。

The Photosynthetic Characters of Alocasia odora C. Koch. and Camellia japonica L. in Greenhouse in Summer

The effect of higher temperature on net photosynthetic rates(Pn)of Alocasia odora C.Koch.and Camellia japonica L.leaves was investigated,which showed that Pn decreased under higher temperature and Pn in Alocasia odora C.Koch.decreased slightly.It was found that Pn decrease wasn't inhibited under ruling out stomata restriction.It was also found that carboxylation efficiency and maximum RuBP regeneration rate declined above optimal temperature,and the maximum RuBP regeneration rate declined seriously.Photorespiration at higher temperature increased.Therefore,we suggest:1)Alocasia odora C.Koch.has better adaptation to higher temperature and Camellia japonica is sensitive to higher temperature; 2)Pn decrease at higher temperature is mainly caused by no-stomata restriction and maximum RuBP regeneration rate decline may be the main restriction factor; 3)photorespiration may also be one of the reasons resulting in Pn decrease.