白叶枯病是水稻生产中最常见的细菌性病害。利用主效抗病基因改良水稻品种一直是水稻生产中最重要的抗病策略。但是因为病原菌的变异,有些主效抗病基因的抗性容易丧失,利用具有持久抗性的抗病基因改良农作物一直是育种家的育种目标之一。在已经被利用的主效抗白叶枯病基因中,Xa4基因是应用范围最广、时间最长的一个。 Bacterial blight is the most common bacterial disease in rice production. Improvement of rice varieties using major disease-resistance genes has been the most important disease-resistant strategy in rice production. However, due to the variation of pathogenic bacteria, some major resistance genes are easily lost. It is always one of the breeders' breeding goals to improve crops by using resistant genes with long-lasting resistance. Xa4 gene is the most widely used and longest one among the major bacterial resistance bacterial blight genes that have been used.