试验表明春油菜的胚长、子叶长宽、胚轴长宽的变化基本同步,都呈现S形曲线,增长峰值出现在花后第14—15天,接近最大值的时间在花后第22—25天。胚干重在花后第28天增加最快,日增量达0.24mg.胚细胞数在花后第22天不再增加,此时胚干重仅为其最终胚重的1/5左右,而胚长已接近最大值,施用氮肥能使胚早期发育延缓,同时能防止胚珠退化,增加粒数,提高粒重。 The results showed that the changes of embryo length, cotyledon length and width and hypocotyl length and width of spring rape were basically synchronous, showing S-shaped curve. The peak appeared in 14-15 days after anthesis, close to the maximum in 22- 25 days. The dry weight of embryo increased fastest at the 28th day after anthesis, and its daily increment reached 0.24mg.The number of blastocyst no longer increased on the 22nd day after anthesis, at which time embryo dry weight was only about 1/5 of its final embryo weight, The embryo length is close to the maximum, the application of nitrogen can delay early embryo development, while preventing ovule degradation, increase grain number, increase grain weight.