Inheritance and Molecular Characterization of a Novel Mutated Gene Responsible for the Resistance of AHAS-Inhibiting Herbicides in Rapeseed ( L.).

The use of herbicides is an effective and economic way to control weeds, but their availability for rapeseed is limited due to the shortage of herbicide-resistant cultivars in China. The single-point mutation in the () gene can lead to AHAS-inhibiting herbicide resistance. In this study, the inheritance and molecular characterization of the tribenuron-methyl (TBM)-resistant rapeseed ( L.) mutant, are performed. Results indicated that TBM-resistance of was controlled by one dominant allele at a single nuclear gene locus. The novel substitution of cytosine with thymine at position 544 in was identified in , leading to the alteration of proline with serine at position 182 in BnAHAS1. The TBM-resistance of was approximately 100 times that of its wild-type , and also showed cross-resistance to bensufuron-methyl and monosulfuron-ester sodium. The transgenic exhibited higher TBM-resistance than that of its wild-type, which confirmed that was responsible for the herbicide resistance of . Simultaneously, an allele-specific marker was developed to quickly distinguish the heterozygous and homozygous mutated alleles . In addition, a method for the fast screening of TBM-resistant plants at the cotyledon stage was developed. Our research identified and molecularly characterized one novel mutative allele in and laid a foundation for developing herbicide-resistant rapeseed cultivars.