低氮胁迫下我国不同年代玉米品种产量及产量构成因子变化趋势研究

Trends of Grain Yield and Component Factor under Low Nitrogen in Chinese Maize Cultivars from Different Eras

试验以我国不同年代的35个玉米品种为材料,在施氮肥和不施氮肥两个水平下对产量、穗长、穗粗、穗粒数、秃尖长、轴粗、百粒重共7个农艺性状进行考查比较。结果表明,除轴粗以外,其余几个农艺性状不同年代间差异均达到显著或极显著水平,随年代变化玉米品种产量显著提高,氮胁迫压力下不同年代玉米品种产量均下降。正常施氮条件下,各年代玉米品种的穗长、穗粗、穗粒数呈上升趋势,低氮胁迫降低了穗长、穗粗、穗粒数及百粒重,而对轴粗无明显影响。研究还表明,1950年以来我国玉米品种的耐低氮能力没有明显提高。育种工作要在自交系选育中重视低氮条件,为进一步培育耐低氮杂交种奠定基础。

Thirty-five maize varieties from 1950 to 2000 were tested.Grain yield,kernel length,kernel diameter,kernels per ear,barren tip length,cob diameter,100 kernel weight were measured under low nitrogen and optimal conditions.The result showed that all traits（except the cob diameter） across decades differed significantly.Maize grain yield,kernel length,kernel diameter,kernels per ear and 100 kernel weight decreased under low nitrogen.Hybrids nitrogen tolerance did not increase obviously.Therefore,the task of maize breeding is to strengthen nitrogen stress pressure in selecting inbred lines,which will establish a foundation for breeding hybrids tolerant to nitrogen.