不同生态区和不同品种玉米的源库关系及碳氮代谢

Source-Sink Relationship and Carbon-Nitrogen Metabolism of Maize in Different Ecological Regions and Varieties

【目的】阐明不同生态区及品种条件下玉米源库协调性、碳氮代谢的差异表现及其与产量的关系。【方法】在东北(吉林省农安)、京津唐(北京昌平)和黄淮海(河南省浚县)3个生态区各设一个试验点,以6个高产、稳产的优良品种为试验材料,在稀植条件下(密度45 000株/hm2)比较不同生态区和不同品种玉米的产量和产量构成、叶面积指数(LAI)和粒叶比、干物质和氮素分配转运、可溶性糖和C/N等指标。【结果】3个试验点的产量表现为农安>浚县>昌平;6个品种中产量最高的是先玉335,最低的是京单28,其它品种间差异不显著。在不同生态区和品种条件下,玉米产量与穗粒数的相关性明显大于千粒重;吐丝期最大LAI与产量的相关性不显著,而粒叶比则与产量成正相关;吐丝后干物质生产量与籽粒产量呈极显著正相关。低产生态条件下,茎鞘内富集了大量的可溶性糖,反映了源-库-流的不协调。在不同生态条件下,C/N与产量呈负相关。根据籽粒氮素的来源可将不同品种归为3类:(1)对后期吸氮(61.0%—68.4%)的依赖高于器官转运氮(39.7%—46.0%);(2)后期吸氮量与器官转运氮量相当;(3)后期吸氮(42.5%—45.3%)低于器官转运氮(57.2%—61.7%)。【结论】适宜生态条件下,玉米源库关系更加协调,表现在粒叶比高、收获指数(包括氮素收获指数)大、灌浆期干物质积累量和氮素吸收量大、茎鞘可溶性糖含量适宜、C/N值相对较低。而粒叶比高、籽粒灌浆期干物质积累量和氮素吸收量大也是高产品种的重要特点。

【Objective】A field experiment was conducted to illustrate different performances of source-sink relationship and carbon-nitrogen metabolism of maize in different ecological regions and varieties in 2009.【Method】Three experimental sites（Nong＇an,Changping and Xunxian） which were located in Northeast,Jingjintang and Huanghuaihai regions,respectively,and six representative varieties were selected.【Result】Grain yields under different sites performed as： Nong＇anXunxianChangping;XY335 got the highest while JD28 got the lowest grain yield among six varieties,and the differences among other four varieties were not significant.Under different ecological conditions,grain yield of varieties was more related to kernels number per ear than kernel weight;and grain yield was positively related to grain-leaf ratio while not to the maximum LAI at silking stage;grain yield also had a high positive correlation with dry matter amount accumulated after silking.Besides,uncoordinated source-sink relationship under low-yielding ecological condition was performed by high soluble sugar content in stem during key growing stages.C/N value showed a negative correlation with grain yield under different ecological regions.Different varieties could be divided into three types according to source of grain nitrogen： 1.nitrogen uptake during late-phase（61.0%-68.4%） was higher than transported nitrogen（39.7%-46.0%）;2.nitrogen uptake during late-phase was equal to transported nitrogen;3.and nitrogen uptake during late-phase（42.5%-45.3%） was lower than transported nitrogen（57.2%-61.7%）.【Conclusion】Coordinated source-sink relationship under high yielding ecological condition was highlighted by high grain-leaf ratio,high HI value（including NHI）,high amount of dry matter and nitrogen accumulated during grain filling period,suitable soluble sugar content in stem,and relatively low C/N value.High-yielding variety also showed a high grain-leaf ratio and high amount of dry matter and nitrogen accumulated during grain filling period.