铝胁迫对龙眼幼苗光合作用的影响

以苗龄7个月的乌龙岭龙眼品种实生苗为材料，研究铝胁迫下龙眼光合作用变化规律。结果表明，铝胁迫影响龙眼幼苗光合作用，导致光合效率降低，非气孔因子成为限制光合作用的主要因子。铝胁迫下，龙眼幼苗叶片叶绿素、类胡萝卜素含量，叶绿素a与叶绿素b的比值、净光合速率（Pn）、CO2饱和点均下降，叶绿素a下降了1．79％～79．73％，叶绿素b下降了1．28％～77．98％，类胡萝卜素下降了3．43％～77．25％：暗呼吸速率（Dr）（PAR=0时的Pn），光补偿点（LCP）提高，光饱和点和表观量子产量降低，CO2补偿点升高，羧化效率降低；光呼吸加强，乙醇酸氧化酶活性提高了7．52％～67．82％；光合磷酸化受到抑制，叶绿体光合磷酸化活性下降了24．46％～77．99％。

Effect of Aluminum Stress on the Photosynthesis of Longan Seedlings

Seedlings of a Wulongling longan variety 7 months old were used as test materials to study the change of their photosynthesis under aluminum stress. Aluminum stress was found to affect the photosynthesis of longan seedlings and reduce the photosynthetic efficiency. The non-stomas factors were observed to mainly hinder the photosynthesis. This study also indicated that the content of chlorophyll and carotenoid in leaves, ration of chlorophyll a to chlorophyll b, net photosynthesis rate (Pn), light compensation point (LCP), apparent quanta yield (AQY), CE and CO2 saturation point were reduced under the aluminum stress. Chlorophyll a, chlorophyll b and carotenoids in the leaves were decreased by 1.79 % ~ 79.73 %, 1.28 % ~ 77.98 % and 3.43 % ~ 77.255 % respectively. However, the dark respiration rate (Dr), LCP, CO2 compensation point and light respiration rate were enhanced. At the same time, aluminum stress restricted the photophosphorylation activity. The photophosphorylation activity and glycolate oxidase activity were decreased by 24.46 %~ 77.99 % and 7.52 % ~ 67.82 % respectively.