种植密度对直播油菜结实期源库关系及产量的调节

Regulation of planting density on source-sink relationship and yield at seed-set stage of rapeseed(Brassica napus L.)

对6种种植密度下直播甘蓝型油菜结实期的源库关系及产量进行了研究。结果表明:角果长、宽分别在开花后19d和25d左右达到最大值,角果大小有随密度增加而减少的趋势;单位角果皮面积承担的籽粒数(SNPA)及单位角果皮面积的籽粒重(PPA)都随密度的增大呈先增后减的趋势;每角粒数和角果长度或角果面积都符合二次曲线关系;随着种植密度的增加(超过1.97万株/667m2),株高、茎粗、单株一次有效分枝数、单株角果数、每果粒数和千粒重均下降,但群体单位面积角果数、角果面积增大,产量增高。密度继续增加,群体单位面积角果数和角果面积减少,产量下降。

The source-sink relationships and yield characteristics of rapeseed at seed-set stage under six planting densities were analyzed. The results showed that the length and width of pod reached maximum at 19d and 25d after flowering, respectively. With the increasing planting density, the pod size reduced graudually. The seed number per unit pod area （SNPA） and the productivity per unit pod area （PPA） increased at the beginning and then started decreasing after the early stage. The pod length and pod surface area and seeds per pod fit quadratic equation. The plant height and stem diameter, the number of first branches per plant, seeds per pod and 1 000-seed weight all declined. The total pods ,pod area and yield per unit area increased first and decreased later with increasing density.