不同栽培模式下春玉米花后衰老的差异性研究

研究不同栽培模式下春玉米花后衰老的差异性，为解析不同模式的产量差异、评价模式优劣和延衰调控提供理论指导。以‘金山27’为供试品种，设农户(NH)、高产(GC)和再高产(ZGC) 3种栽培模式，测定春玉米根冠生理指标的变化规律。不同栽培模式下玉米各层位叶片衰老速率均表现为NH>GC>ZGC，穗位叶衰老速率小于穗上、穗下第3叶。叶片SOD和POD活性均表现为ZGC>GC>NH，酶活性峰值的出现时间ZGC较NH和GC晚10天左右。叶片MDA含量均表现为NH>GC>ZGC，但在不同阶段差异幅度有所变化。根系活力总体上表现为ZGC>GC>NH，且模式间的差异随根层深度的增加而增加；根系活力随生育进程的推移而下降，其降速表现为NH>GC>ZGC。ZGC模式种植密度较高（9万株/hm2），合理的养分调控及深松有效延缓了玉米花后的衰老速度，叶片SOD和POD活性强，MDA含量低。同时深松和氮肥后移提高了花后根系活力，保证了增密后的养分供应，为高产的实现奠定了基础。

Study on Senescence of Spring Maize after Anthesis under Different Cultivation Patterns

Study on senescence of spring maize after anthesis under different cultivation patterns to show the different yield and reveal the quality of patterns, which provided a theoretical basis for defer decrepitude. The ‘Jinshan 27’ was grown under farmer cultivation (NH), high yield (GC) and higher yield (ZGC) condition to study the senescence of Spring Maize after anthesis under different cultivation patterns to assess the indexes of root cap senescence and structure features. The senescence rate of leaf was NH>GC>ZGC at different leaf position, ear leaf senescence rate less than in the third leaf above ear and the third leaf under ear. The activity of SOD and POD of leaves were ZGC>GC>NH, the enzyme activity of ZGC to the peak value than NH and GC late 10 days. MDA content was NH>GC>ZGC, but it differences in different stage. The root vigor was ZGC>GC>NH and the differences of three cultivation patterns was increase with the increase of soil depth; the root vigor decreased in growing and the decreased rate was NH>GC>ZGC. The ZGC pattern has higher planting density (90000 plants/ hm2), it is effective delay the senescence after anthesis under the reasonable nutrient condition and subsoiling, the activity of SOD and POD of leaves stronger and it has lower MDA content. The same time subsoiling and postponing nitrogen application can improve the root vigor, ensure the nutrients supplying after decreased the density, which was beneficial to obtain maize high-yield.