ABSTRACT Shepherd's purse (Capsella bursa-pastoris [L.] Medik.) is a troublesome dicot weed that occurs in major wheat (Triticum aestivum L.) production areas in China. Tribenuron-methyl failed to control shepherd's purse in some fields in Runan County, Henan Province. This study aimed to establish the cross-resistance pattern of a resistant (R) population and explore the potential target-site and non-target-site based resistance mechanisms. Acetohydroxyacid synthase (AHAS) gene sequencing revealed a single nucleotide change of CCT to CGT resulting in the Pro to Arg substitution at amino acid position 197 in resistant individuals. Compared with the susceptible (S) population, R population displayed high level resistance to tribenuron-methyl. Cross resistance patterns showed that the R population was high resistant to flucarbazone-Na; moderately resistant to florasulam; low resistant to pyrithiobac sodium and pyroxsulam, and sensitive to imazethapyr. The pretreatment of malathion reduced the 50% growth reduction (GR50) value of tribenuron-methyl by 29% in the R population, suggesting that target-site resistance and non-target-site resistance mechanisms were both present in tribenuron-methyl -resistance of shepherd's purse. This is the first report of the acetolactate synthase Pro197Arg mutation in shepherd's purse.
Instituto de Investigaciones Agropecuarias, INIA
Chilean journal of agricultural research v.77 n.1 2017
Herbicides cross resistance of a tribenuron-methyl resistant Capsella bursa-pastoris (L.) Medik. population in wheat field