Abstract:

【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’an＞Xunxian＞Changping; 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.

Key words: maize')">maize, carbon-nitrogen ratio, dry matter transportation, nitrogen transportation, soluble sugar, grain-leaf ratio