不同栽培模式对春玉米花粒期叶片衰老特性及产量的影响

EFFECTS OF CULTIVATION PATTERNS ON LEAF SENESCENCE AND YIELD OF SPRING MAIZE DURING FLOWERING MILKING STAGES

为了探讨春玉米防衰增产增效的生理机制与途径,本试验在农户(F)、高产高效(HH)、超高产(SH)、超高产高效(SHH)4种不同栽培模式下,对春玉米花粒期叶片衰老特性进行了比较研究。结果表明:随着春玉米花粒期生育进程,HH、SH、SHH的叶面积指数(LAI)、净光合速率(Pn)、保护酶系统活性呈单峰曲线变化,Pn、叶片保护酶活性在散粉后14d达到峰值;MDA含量一直呈增大趋势;SHH与SH、HH及F相比,有效提高了花粒期叶片保护酶活性,减缓了叶片保护酶活性下降速度和MDA含量的累积。春玉米花粒期不同层位叶片之间表现为下部叶片衰老早于上部叶片,穗部叶片衰老最晚;SHH模式有效地延缓了春玉米花粒期叶片的衰老,提高了氮肥利用率,是实现春玉米高产高效的生理基础。

To discuss the physiological mechanisms and countermeasures related to anti-senescence,productivity and efficiency enhancements,we tested leaf senescence of spring maize during flowering and milking periods in four cultivation patterns,e.g.,the farmer（F） mode,the high productivity and hihg efficiency（HH） mode,the superior high productivity（SH） mode,and the superior high productivity and efficiency（SHH） mode.The result shows that： In this period,dynamics of leaf area index（LAI）,photosynthesis（Pn）,and activity of protective enzyme system in maize under HH,SH and SHH modes presented sigle peaked curves.Pn and the activity of protective enzymes in leaf were the highest at 14 days after pollination,while malondialdehyde（MDA） content continued increasing.Compared with SH,HH and F modes,SHH mode improved the activities of protective enzymes,slowed down the declining of protective enzymes＇ activity and alleviated the accumulation of MDA.During the flowering and milking stages,the lower leaves on spring maize senescenced earlier than the upper leaves,while the ear leaves showed aging at the latest.SHH mode effectively delays leaf senescence,improves the nitrogen use efficiency during the flowering and milking stages,as is the physiological basis for the high yield and high efficiency production of spring maize.