不同类型山苍子植株光合特性研究

Study on Photosynthetic Characteristics of Different Litsea cubeba Types

为给山苍子(Litsea cubeba)植株的栽培管理提供科学依据,以不同类型山苍子植株为研究对象,测定其光合作用参数,探索不同类型山苍子植株的光合特征差异,并对其净光合速率与主要环境因子的相关性进行分析。结果表明,不同类型山苍子植株净光合速率均随光合有效辐射增加呈上升趋势,光合有效辐射为1 800μmol·m~(-2)·s~(-1)时,均达到光饱和点;4年生雄株的净光合速率高于1和2年生植株和4年生雌株。不同类型山苍子植株的光饱和点、光补偿点和表观量子效率均差异显著,4年生雄株的这3个参数均最大,分别为0.264 6μmol·m~(-2)·s~(-1)、1 382.31μmol·m~(-2)·s~(-1)和0.009 1 mol/mol。不同类型山苍子植株净光合速率和蒸腾速率日变化曲线(1年生植株除外)均为双峰形,存在光合“午休”现象。不同类型山苍子植株净光合速率与光合有效辐射均呈显著正相关。种植山苍子时应选光照较强的地方,后期进行适当修剪,并及时给雌性植株补充肥料。

In order to provide scientific basis for cultivation and management of Litsea cubeba,taking different L.cubebas types as research objects,photosynthetic parameters were masured to explore differences of photo-synthetic characteristics of different L.cubebas types,and correlations among net photosynthetic rates and main environmental factors were analyzed.Results showed that net photosynthetic rates of different L.cubeba types showed trends of increase with increase of photosynthetically active radiation,and reached light saturation points when photosynthetically active radiation was 1800μmol·m-2·s-1.Net photosynthetic rate of 4-year-old male plants was higher than those of 1-year-old and 2-year-old seedlings and 4-year-old female plants.There were significant differences in light saturation points,light compensation points and apparent quantum ef-ficiencies of different L.cubeba types,and these three parameters of 4-year-old male plants were the highest,which were 0.2646μmol·m-2·s-1,1382.31μmol·m-2·s-1 and 0.0091 mol/mol,respectively.Diurnal variation curves of net photosynthetic rate and transpiration rate(except for 1-year-old seedlings)of different L.cubeba types had double peaks,indicated that there was lunch break in photosynthesis.Net photosynthetic rates of dif-ferent L.cubeba types were positively significantly correlated with photosynthetically active radiation.Places with strong lights should be selected when planting L.cubeba,and appropriate pruning should be carried out at later stage,and female plants should be supplemented with fertilizer in time.