热研8号坚尼草的光合特性研究

Studies on Photosynthetic Characteristics of Panicum maximum cv. Reyan No.8

2006年9月上旬,在晴天用LI-6400便携式光合仪测定热研8号坚尼草的光合特性。结果显示,热研8号坚尼草的光合日变化呈“单峰型”,无“午休”现象,13:00时出现峰值(Pn为26.9μmol/m2.s),变化趋势与蒸腾速率(Tr)、气孔导度(Gs)等因子相同;叶片光饱和点(LSP)约为1 700μmol/m2.s,光补偿点(LCP)约为46μmol/m2.s,表观量子效率(AQY)为0.0535,CO2饱和点(CSP)为600μmol/mol,CO2补偿点(CCP)为3.49μmol/mol,羧化效率(CE)为0.1168。表明热研8号坚尼草是一种耐荫的C4型阳性植物。

The photosynthetic characteristics of Panicum maximum cv. Reyan No.8 were measured with the LI-6400 portable photosynthesis system on clear days in the first ten days of September 2006. The results showed that the photosynthesis of P. maximum cv. Reyan No.8 presented a single peak curve, no midday depression. The peak appeared at about 13：00 （Pn = 26.911mol/m2-s）, and changed positively with the variations of transpiration rate and stomatal conductance. The light saturation and compensation points of P maximum cv. Reyan No.8 were about 170011mol/m2-s and 46~tmol/m2-s, respectively. The apparent quantum yield, CO2 saturation point, CO2 compensation point and carboxylation efficiency were about 0.0535, 600μmol/mol, 3.49μmol/mol and 0.1168, respectively. These results indicated that P maximum cv. Reyan No.8 was a heliophile C4 type plant with shade-tolerance.