本文总结了粳稻品种间(包括晚×早、晚×中、晚×晚)杂交后代F_1—F_4的生育期研究,以单株抽穗日数为指标。 F_1的基本趋势是早熟对晚熟具有优势,17个杂交组合中有10个较早亲早,一个与早亲相同,两个为中间偏早,两个属于两亲中间型,一个偏晚亲,一个与晚亲同时。 F_2真各个组合的抽穗期都表现连续变异,即出现从早亲到晚亲的抽穗期以及各种中间 This paper summarizes the growth period of F_1-F_4 in hybrids between japonica varieties (including late × early, late × middle, late × late). The index of heading date per plant was used as index. The basic trend of F_1 is that early maturity has the advantage of late maturity. Among the 17 hybrids, 10 have early parents and early ones, one is the same as the early parents, two are middle early, two belong to the intermediate parent, One at the same time with late parents. F_2 really all combinations of the heading stage showed continuous variation, that is, from early to late pro-heading and a variety of intermediate