利用粳型杂种优势群转育恢复系各代遗传效应研究

Genetic effect of restorer line in every bred generation using heterotic group of japonica rice

【目的】利用不同方法将恢复基因导入粳型优势生态型水稻中,分析各世代的遗传效应,为粳型杂种优势群的利用和丰富粳型杂交稻恢复系的遗传基础提供基础数据。【方法】以粳型优势生态群品种高雄13号、嘉农育251和Riw-1为受体材料,以具有恢复基因的C418为供体材料,将带有恢复基因的恢复系与不同生态型杂种优势群中的品种(系)进行杂交和回交,分别对杂交和回交各世代植株的主要农艺性状进行测定与统计分析。【结果】回交选育过程中,各性状都是F1代值最大,BC1F1值最小,随着回交次数的增加,各世代主要农艺性状逐步接近亲本,标准差和变异系数也有减小的趋势;各性状变化幅度为单株产量>有效穗数>穗粒数>穗长>千粒质量>株高;多样性指数低,各世代变化大。杂交选育过程中,随着代数的增加,各世代主要农艺性状的标准差和变异系数下降,各家系内农艺性状差异减小趋于一致,家系间差异较大,性状类型多,整体向优良性状发展,各性状稳定的速度不同,多样性指数高,各世代变化小。【结论】杂交选育恢复系基因纯合速度慢,但具有更多的多样性;回交选育恢复系基因纯合速度快,但多样性减少。

【Objective】Restoring gene was transferred to japonica heterotic ecotype rice by various methods to analyze gene effect in every generation and offer essential data for utilization of heterotic group and diversification of genetic basis for restorer of japonica hybrid rice.【Method】Gaoxiong 13,Jianong 251 and Riw-1 were selected as recipients,and C418 with restoring gene was used as donor plant.Then restorers with restoring gene were subjected to cross and backcross with lines（strains）in various ecotypes heterotic groups,and primary agronomic characters of plant in every generation were measured and analyzed statistically.【Result】F1 generation had the maximum values of all characters while BC1 F1 had the minimum values in backcross and breeding processes.With the increase of backcross time,the characters gradually got closer to parents,while standard deviation and variation coefficient also decreased.The changes of characters were in the order of yield per plant〉effective tiller〉number of grain per ear〉ear length〉1 000-grain weight〉plant height.Genetic diversity index was low and variations in generations were large.With the increase of generation in cross breeding,standard deviation and variation coefficient decreased,difference within every intra-family decreased while difference between-family increased.Types of characters increased and tended to be better.Different characters had different speeds of stabilization,genetic diversity index was high,and differences among generations decreased.【Conclusion】Cross breeding of restorer line was characterized by slow homozygous speed and more diversity,while backcross breeding was opposite.