高产冬小麦的冠层光合能力及不同器官的贡献

通过两年对四个高产冬小麦品种冠层光合速率的测定，探讨了小麦灌浆期不同光合器官对群体光合能力的贡献。结果表明：灌浆期群体光合能力与干物质积累及籽粒产量呈显著的正相关ｒ＝０．９１９０和ｒ＝０．９２７９）。光合器官中，旗叶和倒二叶光合能力强，贡献最大；茎鞘具有与旗叶相仿或稍高的光合潜力；穗部不仅是光合产物贮藏的生物库，而且是重要的光合源，其对冠层光合的贡献一般在１０－１２％左右。但若群体过大，穗部光合贡

Canopy Photosynthesis Capacity and the Contribution from Different Organs in High-Yielding Winter Wheat

Based on two years' experiment upon canopy photosynthesis rate (CPR) in high-yielding winter wheat, the contribution from different organs at grain filling stage was analyzed. The correlations between total CPR and dry matter accumulation, and grain yield were both positively significant. Among all organs, flag leaf and the 2nd top leaf had both high CPR and high contribution. Stem and sheath also owned high photosynthetic potentialities, which were the same as flag leaf or even higher. Ear was not only a "sink" for photosynthate accumulation but also an important "source" of photosynthesis. Its contribution to total CPR was 10-12%. With the increase of planting density, the contribution of ear was .decreased significantly.Canopy photosynthesis capacity was affected by plant density, leaf area index, green leaf area of each stem, and canopy light interception. Different types of varieties and one variety at different planting densities had obviously different photosynthetic capacity.