施氮对不同氮效率玉米干物质形成及籽粒发育的影响

Effect of Dry Matter Accumulation and Kernel Development of Six Maize Varieties Under Different Nitrogen Application

为了揭示不同氮效率玉米在不同氮素水平下籽粒发育和地上部干物质积累的差异,通过田间小区试验,在3个氮素供应水平N0、N1、N2(施纯氮量分别为0、140、210 kg/hm2)下,对6个不同玉米品种(‘屯玉99’(A),‘并单390’(B)、‘郑单958’(C)、‘晋单65’(D)、‘先玉335’(E)、‘潞玉19’(F))干物质的积累变化和籽粒发育进行了对比分析。结果表明:这6个品种可以分为3种不同氮效率类型:高氮高效型(‘屯玉99’和‘并单390’);双高效型(‘晋单65’和‘先玉335’);低氮高效型(‘潞玉19’和‘郑单958’)。在N1(140 kg/hm2)水平下氮素能够明显促进玉米营养体干物质的积累,促进籽粒产量的增加。随着施氮量的增加,高氮高效型和双高效型品种光合碳量增加,为籽粒提供了充足的碳源;高氮高效性品种地上部干物质积累的增加大于籽粒干物质的积累的增加,而双高效品种籽粒干物质积累增加较快。同时,施氮还可以促进这2种类型玉米顶部籽粒发育,增加产量。而低氮高效品种在氮素作用下,营养体干物质有明显增加,籽粒没有明显变化;施氮会促进营养体干物质的转移;同时过高(N2)或过低(N0)的施氮量都会造成其顶部籽粒发育不完善,影响产量。

In order to reveal the differences of kernel development and dry matter accumulation of six maizevarieties under different nitrogen application, field experiment was conducted to investigate dry matteraccumulation and yields under three N levels（N0, N1 and N2） in six maize varieties. The results indicated thatthese six maize varieties could be divided into three types according to nitrogen use efficiency： high-nitrogen-efficiency type ‘（Tunyu99＇and‘Bingdan390＇）, double-effective type ‘（Jindan 65＇and‘Xianyu335＇）, low-nitrogen-efficiency type ‘（Luyu19＇and‘Zhengdan 958＇）. The dry matter accumulation and grain productionwere significantly increased under N1 treatment. As the amount of nitrogen increases, high-nitrogen-efficiencyand double- effective varieties increased in photosynthetic carbon- efficient varieties, provided grain withplenty of carbon source; high-nitrogen-efficiency varieties＇ dry matter accumulation of vegetative increasewas greater than the accumulation of grain dry matter increase, and the grain dry matter accumulation ofdouble-effective varieties increased rapidly. At the same time, nitrogen could also facilitate the two types ofmaize kernel development at the top, to increase production. Under the effect of nitrogen, the low-nitrogen-efficiency varieties＇ vegetative biomass had increased markedly, with no apparent change in grain; nitrogenwould promote the transfer of vegetative biomass, while too high（N2） or too low（N0） nitrogen degrees wouldcause imperfect grain development in the top of the maize, affecting production.