不同株高夏玉米品种同化物积累转运与分配特性

以矮秆玉米品种登海661 (DH661)，中间型玉米品种超试3号(CS3)，高秆玉米品种鲁单981 (LD981)和先玉335 (XY335)为试验材料，研究不同株高夏玉米品种同化物积累、转运及分配特性。结果表明，不同株高类型玉米品种干物质积累量在开花期之前差异不显著，其差异主要表现在开花后，随株高的增加，开花后的干物质积累降低。矮秆品种植株中下部茎秆的碳素分配率比高秆品种低，叶片则相反。通过¹³C同位素示踪研究表明，不同株高类型玉米品种不同部位叶片对产量的贡献不同。随株高降低，中、下部叶片的光合产物转移率相对提高，而上部叶片的转移率有所下降，高秆品种LD981和XY335上部叶片对籽粒的贡献率相对较高，中矮秆品种DH661和CS3下部叶片对籽粒的贡献率相对较高。不同部位叶片在开花前后对籽粒贡献也不相同，高秆品种LD981和XY335上部叶片开花后光合产物的转移率最高；矮秆品种DH661中部叶片开花前光合产物的转移率最高。

Characteristics of Accumulation,Transition and Distribution of Assimilate in Summer Maize Varieties with Different Plant Height

Three types of summer maize varieties,including dwarf cultivar Denghai 661(DH661),medium-height cultivar Chaoshi 3(CS3),high-plant varieties Ludan 981(LD981) and Xianyu 335(XY335) were investigated in this study.The results showed that the difference of dry matter accumulation for different varieties mainly manifested after flowering stage.Along with the increase of the plant height,dry matter accumulation after flowering stage reduced.The carbon distribution rate in lower part of stem in dwarf cultivar was lower than that in the high-plant varieties.The experiment using tracer of isotope 13C showed that the leaves in different parts of plant in different varieties had different contributions to grain yield.With the decrease of the plant height,the dry matter transition of middle and bottom leaves was increased,and that of top leaves was decreased.The relative contribution of upper leaves in high-plant varieties to grains was higher than that in dwarf cultivar that of lower leaves in high-plant varieties was lower.There were differences in the contribution to grain yield of different parts of leaves before or after flowering.For the dry matter transition,the top leaves of LD981 and XY335,as well as the middle leaves of DH661 were the highest.