闽西北山区是我省稻瘟病组成复杂、有繁多强致病小种的分布地带菌。根据宁德、建阳、三明三个地(市)五年来稻瘟病菌生理小种的普查测定表明:其一、1982年和1983年这些地区早稻大面积生产用种的更换,促使稻瘟病生理小种组成和频率的相应变化,总的趋势是小种组成趋向复杂,优势小种向致病力更强的方向发展。如建阳地区1983年更换“二红三七”品种之后,提高了对ZB群小 Northwest Fujian mountainous area is the province of rice blast complex, there are many strong pathogenic bacteria distribution zone bacteria. According to Ningde, Jianyang, Sanming three cities (cities) over the past five years to check the physiological race races of Magnaporthe grisea: First, 1982 and 1983, the large-scale replacement of early rice production in these areas to promote the physiological small Species composition and frequency of the corresponding changes in the overall trend is the trend toward the complexity of races, dominance of race to the stronger pathogenic direction. Such as Jianyang area in 1983 to replace the “two red, three seven” varieties, improve the ZB group small