双低杂交油菜油研七号选育研究──Ⅱ系列品种“早熟型油研七号”的选育

Study on Breeding of Hybrid Variety of Brassica Napus Youyan No.7 Ⅱ Breeding of Youyan No.7 of Precocity

用油研七号的不育和恢复亲本22A和821－77进行早熟性定向系统选择，育成了早熟2287A和早熟821，所配制的“早熟油研七号”（尚未审定，因需要暂用此名，下同）生育期平均提早2天，一次有效分枝数、单株有效角、千粒重等性状比油研七号分别多0.53个／株，39．6个／株和0.229，产量比原油研七号增产3．08％。

Using sterile parent (22A) and restoring parent (821-77) of 'Yougan No. 7' carry out the of precocious. selection as a resuer'Youyan No. 7n of precocious variety has benn bred, its bearing period is moved up 2d, and effective branch effective pod and 1000-gratn weight is compared with 'Youyan No. 7' respectively over 0. 53branch/plant 39. 6pod/plant and 0. 22g/1000-grain, yieldthan 'Youyan No. 7' over 3. 08%.