论文部分内容阅读
稻瘟病是危害水稻产量的重要生物胁迫之一。实践证明,解决这一问题的最有效方法是培育具广谱、持久稻瘟病抗性的品种并推广种植。本研究以优质、高产、感稻瘟病的京作1号为轮回亲本,与稻瘟病抗性基因Pi9、Pigm和pi21的供体材料进行杂交、回交和复交,结合分子标记辅助选择和农艺性状筛选,培育不同的单基因导入系和聚合系。苗期人工接种多个稻瘟病菌的结果显示,Pi9抗性改良系的抗性频率达到100%,Pigm抗性改良系平均为90%,均极显著高于轮回亲本京作1号的抗性频率,且农艺性状与京作1号基本一致。pi21抗性改良系的抗性水平与京作1号没有明显差异,单株产量极显著低于京作1号。与轮回亲本相比,Pi9和pi21聚合系的抗性频率极显著提高,达到93.33%,但单株产量明显降低。研究结果证实了Pi9和Pigm基因在大幅度提高抗瘟性的同时对主要农艺性状影响小,都具有较大的育种利用价值。基因pi21抗谱较窄,抗性不强,且可能存在对产量的负效应,不宜单独用来改良水稻品种的稻瘟病抗性,需要与抗性强的主基因聚合,通过多次回交和自交打破该基因与产量的不利连锁累赘。
Rice blast is one of the important biotic stresses that endanger the yield of rice. Practice has proved that the most effective way to solve this problem is to breed and promote the cultivation of broad-spectrum and long-lasting varieties with resistance to blast disease. In this study, Jingzuo 1, a high-quality, high-yielding and blast-susceptible rice, was crossed with donor materials Pi9, Pigm and pi21, backcrossed and backcrossed, and combined with molecular marker-assisted selection and agronomic traits Screen, cultivate different single-gene introduction lines and polymerization lines. The results of artificial inoculation of multiple Magnaporthe grisea in seedling stage showed that the resistant frequency of the improved line Pi9 reached 100% and the improved line of Pigm resistance averaged 90%, which were significantly higher than that of the recurrent parent Jingzuo 1 Frequency, and agronomic traits and Beijing for 1 basically the same. The level of resistance of pi21 improved lines was not significantly different from that of Jingzuo 1, and the yield per plant was significantly lower than that of Jingzuo 1. Compared with the reincarnated parents, the frequency of resistance of Pi9 and pi21 aggregates increased significantly, reaching 93.33%, but the yield per plant was significantly lower. The results confirmed that Pi9 and Pigm gene had great effect on breeding anti-rice blast, but had little effect on the main agronomic traits. Gene pi21 anti-spectrum narrow resistance is not strong, and there may be a negative effect on yield, should not be used alone to improve rice varieties of rice blast resistance, the need and resistance of the main gene polymerization, by multiple backcrossing and self Hand over to break the unfavorable linkage between the gene and yield.