WANG Dongyuan, WANG Jichun, SUN Wenxian, ZHU Feng, WU Xian, QI Shanyan, OU Yuping
To master pathogenic characteristics of Pyricularia oryzae is the premise and foundation of screening germplasm, breeding resistance, and deploying rice varieties resistant to blast. In this study, total 166 isolates of rice blast fungi were collected from Japonica rice planting area in Jilin Province, northeast China, and were inoculated to 7 Chinese differential varieties (CDVs) and monogenetic differential varieties (MDVs) which harbored 23 resistance genes in greenhouse condition, then pathogenicity was clarified in accordance with compatibility reaction. Those isolates were categorized into 7 groups and 44 races according to the CDVs' phenotypes, in which the dominant Chinese race group was ZA at the frequency of 45.18%, and the dominant races were ZA17(19.28%) and ZG1(9.64%), respectively. No dominant race types with U-i-k-z-ta criteria were demonstrated according to the MDVs' phenotype data, but the sub-groups data were prominent, and the higher sub-groups with frequency were U73(47.0%), i5(31.9%), and i7(31.9%), respectively. Based on the MDVs data, the higher frequency of the avirulence genes, Avr-Pi12(74.69%), Avr-Pi9(72.28%), Avr-Pi19(68.67%), and Avr-Pi20(68.07%), which indicate that broad spectrum genes were Pi12(t), Pi9(t), Pi19(t), Pi20(t), respectively. The information of the types of dominant avirulence genes not only presents the pathogenicity of blast fungus, but also reflects the types of genes with varieties of broad spectrum resistance in MDVs, so it would be benefit for breeding resistant to rice blast.
