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.

In 2021 and 2022, the resistance level of 16 major rice varieties to Fusarium head blight (FHB) in Jiangsu Province was evaluated under artificial and natural infection conditions. Meanwhile, the accumulation level of trichothecenes, including nivalenol, deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, and fusarenone X, was also detected in these rice varieties. The results showed that 9 rice varieties, including 4 japonica varieties and 5 indica varieties, were moderately resistant to FHB under artificial infection conditions, and the resistance of different rice varieties to FHB in 2021 was consistent with that in 2022, with indica varieties showing significantly higher resistance to FHB than japonica varieties (P<0.05). However, under natural infection in the field, the resistance of different rice varieties to FHB was quite different between 2021 and 2022, and the result was also different from that obtained under artificial infection conditions. In addition, the resistance of indica rice varieties to FHB was also higher than that of japonica varieties. Moreover, the accumulation level of trichothecenes was different among various rice varieties, and there was a significantly positive correlation between trichothecene content and disease index (P<0.01). Our results reveal the resistance of main rice varieties to FHB in Jiangsu Province, making the basis for evaluation of resistance level of rice varieties against FHB and breeding and deployment of FHB-resistant rice varieties.