摘要
通过对濒危植物红花木莲苗期光合生理特性的研究。结果表明,红花木莲苗期的光合日进程呈明显的双峰曲线,峰值分别出现在上午9 00和下午15 00左右。在中午13 00左右出现光合作用明显下降的光午休现象。光午休现象的出现可能与当时气温的升高和湿度饱和差的增加有关,因此使叶保卫细胞失水增多导致气孔导度减小以致引起光合速率下降。此外,也可能与二氧化碳羧化酶的活性降低有关。分析红花木莲苗期的水分利用效率,发现苗木的水分利用效率与其光合速率的日变化趋势有较大的一致性。对红花木莲的叶片的光响应曲线进行分析,得到红花木莲苗期的光补偿点和光饱和点。其光饱和点和光补偿点分别为1200～1300μmolCO2·m-2·s-1和23 487μmol·m-2·s-1。
Study was conducted on the phytosynthesis characteristics Manglietia insignis at seedling stage. The results indicated that the daily progress of phytosynthesis was a obvious double-peak curve. The peak values were at 9:00 am and 300 pm respectively. Light noon break occurs at about 100 pm, the phytosynthesis declines a lot. The phenomenon of light noon break might be related with the increase of temperature and the increase of humidity saturation deficit, since the water loss of guard cells in leaves induce the shrinking of stoma. Besides, the activity of CO(2) carboxylase might be somewhat responsible for the decrease of phytosynthesis. It was also found that the water utilization of seedling stage was consistent with daily change of phytosynthesis ratio to a big extend. Through analyzing the light response curve of the leaves of Manglietia insignis, the light compensation point and light saturation point of Manglietia insignis at seedling stage were deduced. The light compensation point and light saturation point of were 1 200～1 300μmolCO(2)·m^(-2)·s^(-1)和23.487μmol·m^(-2)·s^(-1) respectively.
出处
《西部林业科学》
CAS
2004年第2期42-45,共4页
Journal of West China Forestry Science
关键词
红花木莲
苗期
光合特性
净光合速率
蒸腾日
Manglietia insignis
seedling stage
physiological characteristics of phytosynthesis
