苦竹叶片光合及水分利用率特性

为了给经营管理苦竹者提供较好的科学理论依据,作者采用LI-6400XT便携式光合测定仪,以野生苦竹林为研究对象,测定了其光合及水分利用率。结果表明:(1)苦竹净光合速率和蒸腾速率日变化均为双峰型,存在光合"午休"现象。(2)气孔导度与净光合速率呈极显著的线性关系,而且气孔导度是影响苦竹光合的主要限制因子,所以苦竹光合"午休"主要受气孔因素限制。(3)苦竹的水分利用率比较低,节水抗旱能力比较差。(4)苦竹的光补偿点为8.10μmol/(m2.s),光饱和点为1 198.66μmol/(m2.s),说明苦竹具有较强的耐阴能力,能适应较宽的光照环境。

Characteristics of Photosynthesis and Water Utilization Efficiency of Pleioblastus Amarus Leaves

Photosynthesis and water utilization efficiency of wild bitter bamboo(Pleioblastus amarus) were measured using portable photosynthetic analyzer LI-6400TX in order to provide a scientific basis for the management of Bitter Bamboo.Results showed that the curves for diurnal changes in net photosynthetic rate and stomatic conductance of Bitter Bamboo exhibited two peaks and the obvious phenomena of midday depression.Stomatic conductance had a significant linear relation with net photosynthetic rate.Stomatic conductance was found to be a key limiting factor for the photosynthesis of Bitter Bamboo and therefore,the midday depression was mainly regulated by the stomatic factor.Water utilization efficiency of Bitter Bamboo was relatively low,indicating that it is poor in water-saving and drought resistance.Light compensation point and light saturation point of Bitter Bamboo leaves were 8.10 and 1 198.66 μmol/(m2·s),respectively,indicating that Bitter Bamboo is a shade-tolerant species and can adapt to a wider lighting condition.