不同海拔来源宽刺蔷薇的光合日变化及其生理机制

Daily Photosynthetic Changes and Physiological Mechanisms of the Seedlings of Rosa platyacantha from Different Altitudes of Xinjiang

以来源于不同海拔高度的3个新疆宽刺蔷薇1年生实生苗为材料,在引种地北京测定光合作用日变化以及13:00的荧光参数、抗氧化生理指标。结果表明,来源不同海拔的宽刺蔷薇植株都在9:00以后出现净光合速率的持续降低,在上午受到气孔限制,中午则主要受非气孔限制,即PSⅡ反应中心活性的影响。各植株在13:00均受到不同程度的光抑制,与来源中、低海拔植株相比,来源高海拔的植株PSⅡ反应中心活性与热耗散能力均显著降低,即发生了更显著的光抑制效应;POD、APX酶活性以及AsA/DHA等酶类和非酶类抗氧化物质在高海拔来源植株中显著升高,以抵抗光氧化胁迫,但仍然造成了过剩的活性氧累积以及植物组织的膜脂过氧化伤害。

The parameters of photosynthesis,chlorophyll fluorescence and antioxidant systems during the day or at 13：00 were ex situ measured in Beijing on the leaves of 1-year-old seedlings of Rosa platyacantha from three different altitudes from Xinjiang. The results showed there were continuous declines of P n after 9：00 on the seedlings of R. platyacantha from all altitudes,which should be due to stomatal limitation in the morning while non-stomatal limitation at noon. In comparison to the seedlings from low and medium altitudes,the impaired PSⅡ activity and heat dissipation were observed at 13：00 in the seedlings from high altitude,indicating a worse photoinhibition. Moreover,the antioxidant system including POD and APX activities,as well as AsA/DHA were enhanced at 13：00 but still led to the excessive ROS and lipid peroxidation in the seedlings from high altitude,which suggesting the significantphotodamage happened.