“门源油菜”是门源县种植了多年的优良农家品种。但由于对选种和留种重视不够,混杂退化严重。植株越来越矮,干尖长(不结实花序),角果变小,并有空粒,籽粒变小,影响产量。群众说:“小油菜越种越小。”在辽宁等省新产区,从原产地调运的种子混杂退化更为严重。因此,搞好“门源油菜”的选种留种工作,建立种子田,注意栽培管理,是非常必要的。其方法是:一、株选:在收获前1—2天,组织专门人员到田间选择具有该品种典型性强、生长健壮、成熟一致、没有病虫害的植株,选拔到一起, “Door source rape” is a good farmhouse variety grown for many years in Mengyuan County. However, due to the lack of attention to the selection and breeding, mixed degradation is serious. Plants shorter and shorter, dry pointy (not fruiting), angle smaller, and have empty grain, grain smaller, affecting the yield. The masses said: “The smaller the smaller rape.” Liaoning and other provinces in the new producing areas, transported from the origin of the seed mixed degeneration is even more serious. Therefore, it is very necessary to do a good job of selecting and planting seedlings of “Canolaeyuan”, establish seed fields and pay attention to cultivation and management. The method is: First, strain selection: 1-2 days before harvest, the organization of specialized personnel to the field to choose to have the typical varieties of strong, robust growth, mature, without pests and diseases of plants, selected together,