高产玉米叶片冗余及其对产量和光合特性的影响

为探明高产玉米群体是否存在叶片冗余现象，根据2007年15000株·hm^-2密度下的产量结果，筛选出低密度条件下的冗余类型(超试1号)和非冗余类型(超试3号)，2008年将两品种在各自最适密度的高产条件下进行开花期整株剪叶1/2（T₁）和1/4（T₂）处理，以其地上部干物质积累量和籽粒产量的变化来证实叶片冗余现象的存在；以Richards模型拟合籽粒灌浆过程；以穗位叶光合特征参数和叶绿素荧光参数来评价去除冗余叶片后光合生理特性的变化.结果表明：不同冗余类型的两个玉米品种，在最适密度的高产条件下都存在叶片冗余现象；适当去除玉米群体冗余叶片可以延长植株活跃灌浆时间，有利于获得较高籽粒产量；去除冗余叶片提高了玉米穗位叶净光合速率和光能利用效率.

Leaf redundancy of high-yielding maize (Zea may L.) and its effects on maize yield and photosynthesis

According to the maize yield at plant density of 15000 ind·hm^-2 in 2007, the leaf-redundant type (cultivar Chaoshi 1) and non-redundant type (cultivar Chaoshi 3) at low plant density were selected, and the changes of their above-ground dry matter accumulation and grain yield after cutting all leave
s to 1/2 (T₁) and 1/4 (T₂) at anthesis at the optimal density and under high-yielding condition were analyzed in 2008, aimed to approach whether the leaf redundancy exists in high-yielding maize colonies. The characters of grain-filling were simulated by Richards’ model, and the photosynthetic characteristics and chlorophyll fluorescence of the leaves on ear position were determined to reveal the activities of photosynthesis after the removal of redundancy. The results showed that at optimal plant density and under high-yielding condition, both the redundant and non-redundant types had leaf redundancy. The characterization of grain-filling by Richards’ model indicated that appropriately removing redundant leaves could increase the net photosynthetic rate and solar energy use efficiency of the leaves on ear position, extend the active period of grain-filling, and enhance the grain yield.