MAS 育种改良籼稻恢复系‘E32’及其杂交种的稻瘟病抗性

摘要

利用已克隆的广谱抗稻瘟病基因 Pi9的 DNA 序列，设计功能分子标记 Ins2-3，通过标记基因型辅助选择和连续回交育种实践，定向改良籼稻恢复系 E32及其两系杂交种培矮64S ／E32的稻瘟病抗性。获得以下结果：Ins2-3是一个高效共显性 DNA 标记，在 Pi9供体亲本75-1-127和受体亲本 E32基因组中分别扩增出一条793 bp 和2 kb 的稳定条带，Ins2-3的辅助选择效率达100％；利用 Ins2-3开展分子标记辅助选择育种，通过连续多代回交自交，育成了苗瘟和穗瘟抗性均显著提高的新恢复系 E32-Pi9，其遗传背景与受体亲本 E32一致；用 E32-Pi9配制的两系杂交种培矮64S ／E32-Pi9的稻瘟病抗性，比对照培矮64S ／E32显著提高，而主要农艺性状及杂种优势表现非常相似。%To improve blast resistance of the indica rice restorer E32 and its hybrid,a molecular marker,Ins2 -3,was de-veloped based on the DNA sequence of the cloned broad -spectrum blast resistance gene Pi9,and marker -assisted selec-tion breeding practice was implemented in this study.The main results were as follows:Ins2 -3 was a co -dominant mark-er,showing stable polymorphism between the Pi9 donor 75 -1 -127 and the receptor E32 by producing a 793bp and a 2kb PCR band respectively,and the phenotype selection efficiency by marker genotype reached 100%.A new restorer line E32-Pi9 and its hybrid Peiai64s/E32 -Pi9,with high -level seedling and spike blast resistance and unchanged genetic background,were bred.