5种狼尾草属观赏草光合特性研究

Study on the Photosynthetic Characteristics of Five Pennisetum Speices

为了解东方狼尾草（Pennisetum orientale）、绒毛狼尾草（P.setaceum）、＇小兔子＇狼尾草（P.alopecuroide＇sLittle Bunny＇）、羽绒狼尾草（P.villosum）和＇紫光＇狼尾草（P.alopecuroide＇sZiguang＇）5种观赏草光合特性,为引种驯化、园林应用提供理论依据,采用Li-6400便携式光合分析仪测定其光合特性指标。结果表明：5种狼尾草光合日进程均呈单峰型,无＂午休＂现象,＇紫光＇狼尾草净光合速率和蒸腾速率在11∶30达最大值29.5μmolCO2/（m^2·s）、5.94mmolH2O/（m^2·s）,为5种狼尾草中的最高;东方狼尾草光补偿点最高为58.70μmol/（m^2·s）,绒毛狼尾草、＇小兔子＇狼尾草、羽绒狼尾草相近,＇紫光＇狼尾草最低为32.41μmol/（m^2·s）;羽绒狼尾草光饱和点最高为2563.6μmol/（m^2·s）,东方狼尾草最低为1615.4μmol/（m^2·s）;5种狼尾草表观量子效率与耐荫植物接近,在0.059~0.061之间,其光能利用效率和水分利用效率均较高,表明5种狼尾草均为耐荫的阳性节水园林植物。

The study was focused on 5 species of Pennisetum spp.in order to investigate the photosynthetic characteristics with the Li-6400 portable photosynthesis system,with the main purpose of providing theoretical basis for its introduction and application in garden greening.The results showed that daily variations of net photosynthetic rate of the five species were all single-peak curves,Pennisetum alopecuroides ＇ Ziguang ＇ had the highest peak value of net photosynthetic rate and transpiration rate at 11：30 a.m.,which was 29.5 μmolCO2 /（m^2·s） and 5.94 mmolH 2O/（m^2·s）.The light saturation points ranged between 33.458.7μmol/（m^2·s）.P.alopecuroides ＇ Ziguang ＇ had the lowest and P.orientale had the highest light saturation point.P.setaceum,P.alopecuroides ＇ Little Bunny ＇ and P.villosum had similar light saturation point.The five species had high value of light saturation point,ranging between 1615.4 μmol/（m^2·s） for P.orientale and 2563.6 μmol/（m^2·s） for P.villosum.The apparent quantum efficiency ranged from 0.059 to 0.061.The five species had high solarenergy utilization efficiency and water utilization efficiency,indicating that they were heliophilous plants with some shade tolerance.