通过对72个杂交组合主要经济性状的杂种优势测定结果表明:杂交粳稻的优势是很强的,主要表现在产量、穗粒数、粒重及株高等性状上,生育期、单株有效穗和结实率等性状优势较弱。杂交粳稻F_1的生育期、穗长、穗粒数千粒重及株高与双亲平均值呈显著正相关,可通过双亲平均值来预测杂种F_1的表现。通过对6种估算方法比较得知,利用竞争优势法和优势指数法测定粳稻的杂种优势是可靠的,所得的结果是符合实际情况的。在配制杂交组合时要选择穗大、结实率高、分孽力强的恢复系做父本,母本不育系注意选用矮杆、大粒类型。如希望选育早熟杂交种时,则应选用生育期短的不育系做母本。 The results of heterosis analysis on the main economic traits of 72 hybrid combinations showed that hybrid japonica rice had strong advantages, such as yield, grain number, grain weight and plant height, Seed setting rate and other traits are weaker. The growth period, spike length, grain weight of 1000 grains per spike and plant height of F1 hybrid were positively correlated with the average of parents, and the average of parents could predict the performance of F1 hybrid. By comparing the six kinds of estimation methods, it is reliable to determine the heterosis of japonica rice by competitive advantage and dominant index, and the results obtained are in line with the actual situation. In the preparation of hybrid combinations to choose big ears, high seed setting rate, strong offensive power offspring as father, female sterile line pay attention to the selection of dash, large grain type. If you want to breed precocious hybrids, you should use a short male sterile line to do the female parent.