Abstract:Fomesafen is one of the herbicides commonly used in soybean production, and overdose application may cause plant damage and yield reduction. In this study, 346 soybean accessions mainly from northeast China were planted in the greenhouse, and the post-emergence herbicide fomesafen were applied by spraying 2× recommended application dose to V2 stage soybean seedlings, and the tolerance of each soybean accession to fomesafen was evaluated according to the leaf damage index. The results showed that all soybean accessions exhibited leaf damage symptoms when overdose fomesafen was applied, and the damage index was between 11.30 and 73.33, with an average value of 36.68. No high-resistance accession was found in the test panel, and 18 resistant accessions were found, accounting for 5.2% of all tested accessions. Soybean germplasms from Jilin province were more tolerant to fomesafen than those from Heilongjiang and Liaoning provinces, and the breeding varieties (lines) were more tolerant to fomesafen than that of landraces. Correlation analysis showed that the herbicide damage index was positively correlated with seed color, growth habit, seed coat color, protein content, and negatively correlated with leaf shape and fat content. This study can provide plant materials for the genetic and molecular mechanism of resistance to fomesafen, and also useful information for safe soybean production and rational herbicide application in soybean field.