利用抗稻瘟病基因Pigm和抗纹枯病数量性状基因qSB-9TQ、qSB-11HJX改良南粳9108的抗性

Improvement of the Resistance of Nanjing 9108 to Blast and Sheath Blight by Pyramiding Resistance Gene Pigm and Quantitative Trait Genes q SB-9TQ and qSB-11HJX

【目的】稻瘟病和纹枯病是水稻两大重要病害,严重影响稻米的产量和品质。培育抗病品种是降低其危害最经济有效的措施。【方法】本研究结合分子标记辅助选择技术,将广谱抗稻瘟病基因Pigm和抗纹枯病数量性状基因qSB-9^(TQ)、qSB-11^(HJX)导入优良食味粳稻品种南粳9108中,构建不同抗性基因/基因组合的株系,并评价这些株系的稻瘟病和纹枯病抗性,考查其主要农艺性状和品质性状。【结果】导入Pigm能显著提高南粳9108对苗瘟和穗颈瘟的抗性;分别导入qSB-9^(TQ)、qSB-11^(HJX)均能提高南粳9108的纹枯病抗性,且两个抗性基因聚合时呈现一定的抗性累加效应。其中,导入Pigm的株系穗长和每穗粒数显著增加,导入qSB-11^(HJX)的株系千粒重显著增加,其他农艺及品质性状与南粳9108无明显差异。【结论】这些抗性基因导入/聚合能在不降低农艺及品质性状的同时,显著提高纹枯病和稻瘟病的抗性水平,为粳稻抗病育种提供新的种质资源。

【Objective】Blast and sheath blight are two major diseases in rice,causing huge yield and quality losses.Breeding resistant varieties is the most economical and effective approach to control the two diseases.【Method】Using molecular marker assisted selection,we introduced the broad-spectrum blast resistant gene Pigm and quantitative resistance genes qSB-9TQ,qSB-11HJXto sheath blight into Nanjing 9108,a japonica rice cultivar with good grain quality.Plant lines with different gene/gene combinations were obtained and the resistance phenotypes were identified as well as the main agronomic and quality traits.【Result】The inoculation results showed that Pigm introduction could increase rice resistance to seedling blast and panicle blast significantly.Both q SB-9^(TQ)and qSB-11^(HJX)could improve rice sheath blight resistance significantly.Moreover,pyramiding of the two quantitative resistance genes had an additive effect on sheath blight resistance.As for the main agronomic and quality traits,the lines with Pigm showed increased panicle length,number of grains per panicle and the lines with qSB-11^(HJX)showed significantly increased grain weight.Incorporating these genes exerted no significant effect on other agronomic and quality traits.【Conclusion】Pyramiding the three genes could improve blast and sheath blight resistance without apparently negative effect on agronomic and quality traits,and the pyramided rice line can be used as a new germplasm for breeding disease-resistant japonica rice varieties.