摘要
通过测定土培条件下净光合速率及其相关参数的日进程，发现胡杨净光合速率的最大值出现在中午辐射最强的时间；胡杨光饱和点高达２８００μｍｏｌｍ－２ｓ－１，说明具有Ｃ４植物的光合特性，但ＣＯ２补偿点和饱和点分别高达１５０μｍｏｌｍｏｌ－１和９００μｍｏｌｍｏｌ－１，说明胡杨仍属于Ｃ３植物．此外，扫描电镜观察胡杨叶片表面有蜡片结构，可能与胡杨长期适应沙漠强辐射和高蒸腾的环境有关．胡杨气孔阻力全天变化不大，表明胡杨的气孔运动保留了河岸起源的特点。
The measurements on photosynthesis and related parameters indicated that CO 2 compensation point and saturation point increased,while Rubisco activity decreased with the increase of salt stress for two genotypes Under high salt treatment,the net photosynthesis of P euphratica recovered from salt stress when soil salt content was about 0 7% NaCl,while that of hybrid only recovered when soil salt content was less than 0 2% NaCl and was unable to when soil salt content was about 0 5% NaCl;chlorophyll a contents and Chl a/b ratio increased,while chlorophyll b and carotenoid contents decreased with increasing salt levels Fluorescence patterns confirmed that reduction of photosynthesis under high salt treatment was not due to damage of photosynthetic apparatus but due to inhibition of the dark reaction
出处
《西南林学院学报》
CAS
1998年第1期24-32,共9页
Journal of Southwest Forestry College
基金
国家自然科学基金
国家教育委员会"优秀青年教师基金"资助
关键词
胡杨
日进程
气体交换
光合作用
P euphratica
Diurnalpattern
Gas exchange
Photosynthesis
