不同熟期大豆R4-R5期冠层某些生理生态性状与产量的关系

 应用冠层分析仪和光合测定系统，分析不同熟期、不同产量类型的大豆R4-R5期冠层结构特征、光合生理、冠层内微生态环境。结果表明，不论熟期早晚，高产大豆群体的共同特征在于LAI较高，叶片在各个方向上的分布均匀；上下冠层叶片的光合速率差异小，全冠层的光合速率相对较高，从而使全冠层有较高的光合生产力。结果增加了植株荚、粒数及粒重，特别是增加了中上部的荚、粒数。不同熟期间的高产群体冠层特征的差异在于早熟大豆的LAI相对较低，截获的光能多少对于产量形成有着更重要的意义，高产群体叶倾角小，叶片平展，有利于截获更多光能；而晚熟大豆冠层郁蔽，LAI大，高产冠层各层次叶倾角大则有利于太阳辐射透射到冠层内部，增加群体内部受光量，利于产量形成。

Some Eco-physiological Characteristics at Rt-Rs Stage in relation to Soybean Yield Differing in Maturities

Digital plant canopy imager and photosynthesis analyzer system were used to analyze characteristics of canopy structure, photosynthetic physiology and micro-environmental factors at R4-R5 stage in different yielding soybean cultivars or lines with different maturities. The results showed that the common traits of high yielding soybean were high in LAI, uniform in foliar distribution in all horizontal directions, less variance of photosynthetic rate between top and bottom leaves in canopy and relatively high photosynthetic rate of the whole canopy to enhance photosynthetic productivity. Thus, pod number, seed number and seed weight per plant,especially pod and seed number in top and medium canopy increased. The characters of high yielding colony in different maturing cultivars were different. Light interception was more important for early cultivars. Less foliage inclination angle would be benefit to intercept more solar energy during yielding period; but for late soybean cultivars, the colony was more closure and LAI was higher, so big foliage inclination angle in all layers of high yielding colony made more solar radiation penetrate into the inner canopy, which would be good for yield formation.