分子标记辅助选育聚合抗稻瘟病基因Pi5及Pita的水稻新品系

Molecular Markers-assisted Selection of New Rice Lines with Blast Resistance Gene Pi5 and Pita

稻瘟病是对水稻生产具有严重威胁的真菌病害,选育并推广聚合多个抗稻瘟病基因的抗病品种是防控该病最为经济有效的途径。本研究以携带不同抗稻瘟病基因的‘吉粳105’(Pita)和‘T639’(Pi5)为亲本杂交衍生的后代群体为试材,利用分子标记辅助育种技术,筛选到3个聚合抗稻瘟病基因Pita和Pi5的后代。并以其中一个株系‘吉2011TK50’为试验材料,利用人工接种鉴定、显微观察及定量PCR等技术研究‘吉2011TK50’的抗病表型及抗性分子机制。结果表明,抗稻瘟病基因的聚合能够增强该品系对稻瘟病的抗性。显微观察和抗稻瘟病基因表达分析发现,基因聚合株系在接种稻瘟病菌后24 h PR基因表达量显著升高,被稻瘟病菌侵染的细胞开始出现过敏性死亡等抗病反应,抑制了稻瘟病菌的进一步侵染。研究结果证实聚合Pita和Pi5可提高水稻品种对抗稻瘟病的抗性,这可为抗病基因聚合育种提供参考。

Rice blast is a serious fungal disease in rice production.It is the most economical and effective way to control the disease by breeding and planting varieties with multiple blast resistant genes.In this study,three lines with both blast resistant genes Pita and Pi5 were screened by marker-assisted selection from population of’Jijing105’(Pita)/’T639’(Pi5).One of the lines,’Ji2011 TK50’,was used to analyze the disease resistance phenotype and molecular mechanism of resistance to different strains of Magnaporthe oryzae by artificial inoculation identification,microscopic observation and quantitative PCR.The results showed that the pyramiding of Pita and Pi5 enhanced the blast resistance.By microscopic observation and the gene expression analysis,the gene expression of PR,a related gene of blast resistance,was significantly increased in’Ji2011 TK50’at 24 h after inoculation,and the cells infected by blast fungus began to exhibit some resistant reactions,such as hypersensitive necrosis,which inhibited the further infection of blast fungus.Our results suggested that gene polymerization played an important role in the breeding of rice blast resistant varieties,which could provide reference for disease resistance gene polymerization breeding.