甜菜群体光合作用部分特性的研究

在田间采用一个品种三种密度处理条件下研究了甜菜群体光合作用部分特性。其结果表明群体光合作用季节性变化为单峰曲线，日变化为双峰曲线，不同群体光合速率日变化、季节性变化规律均与群体大小有关。不同群体在不同生育时期光合作用需光曲线的形状基本一致。但光补偿点与光饱和点略有不同般光补偿点在０．８－１．１万Ｌｕｘ，光饱和点在６．０－８．０万Ｌｕｘ范围内变化。大密度群体光补偿点大于小密度群体光补偿点。ＣＯ２浓度

A Study on the Part Characteristics of Canopy Apperent Photosynthesis

One sugarbeet variety was planted in three densities to study the part characteristics of canopy apparent photosgnthesis (CAP). The results indicated the season vartation of CAP in sugarbeet was a single peak curve,the CAP value came to the maxtrium in the early root growing stage,the diurnal varintion of CAP belonged to the midnap troe. The relationships between the CAP with light intensity and carbon dioxide concentration also were studied by shading and changing the carbon dioxide concehtration during the leaf formation stage and root growing stage. The experiment showed that the light compensation point and light saturation point were 8 ~11klux and 60~80 kLux respectively, the relationship between CAP with carbon dioxide concentration when lower than 600 mg/kg was linear, and the carbon dioxide compensation point was 100~ 120 mg/kg.