【摘要】 在试验大田，利用Ｌｉ－Ｃｏｒ６２００光合测定系统，以中秆大穗型品种鲁谷１０号和矮秆紧凑型品 种矮８８为材料，初步研究了夏谷群体光合作用特性及其影响因素。结果表明，夏谷光合日变化呈单峰 曲线，上午１１时前后群体光合达最大值，其趋势与光照强度的变化基本吻合。两品种的群体光补偿点 为 １８０～１９０ μＥ· ｍ－２· ｓ－１，鲁谷 １０号对高光强的利用率高于矮 ８８。矮 ８８的 ＣＯ２补偿点为 ４５μＬ· Ｌ－１，低于鲁谷 １０号（６５ μＬ· Ｌ－１）。土壤呼吸释放的ＣＯ２对群体光合有较大的贡献，平均所占 比重达２５．９６％。更多还原

【Abstract】 The study was conducted in the experimental field during 1994- 1995 to investigate the traits of canopy photosynthesis (CAP) and its influencing factors of summer-sowing millet. Two varieties of middle height Lugu No. 10 and dwarf compact type Ai88 were tested using LiCor 6200 photosynthetic analysis system. Main results are as follows: the diurnal changes of CAP was a single peak curve. The highest CAP was at 11 o’clock and the diurnal change of CAP was basically coincided with the change in solar radiation. The canopy light compensate points of two varieties were from 180 to 190 μE. m-2. s-1. Utilization efficiency for higher intense solar radiation of Lugu No. 10 was higher than that of Ai88. The CO2 compensate point of compact type variety Ai88 was 45 μL. L-1, which was lower than that of Lugu No. 10 (65 μL· L-1). CO2 released from soil accounted for a big part in the CAP, about 26%.更多还原