An effective method, composed of LAMP and dCAPS, to detect different mutations in fenoxaprop-P-ethyl-resistant American sloughgrass (Beckmannia syzigachne Steud.) populations.

The decreased susceptibility of Beckmannia syzigachne to fenoxaprop-P-ethyl is due to the reliance on it to control grass weeds since the 1990s. Loop-mediated isothermal amplification (LAMP), which is a proven simple, rapid, specific, sensitive and inexpensive assay method, has been used to detect the I1781L mutation in B. syzigachne. In the present study, four sets of primers detected four mutations in B. syzigachne, W2027C, I2041A, D2078G and G2096A, using the LAMP method. Additionally, five newly derived cleaved amplified polymorphic sequence (dCAPS) markers were developed to detect five different mutations. With a method composed of LAMP and dCAPS, 19 fenoxaprop-P-ethyl-resistant B. syzigachne populations collected in 2013 were studied. An effective method, composed of LAMP and dCAPS, to detect five mutations, I1781L, W2027C, I2041A, D2078G and G2096A, in B. syzigachne populations was developed. With this method, a B. syzigachne population resistant to fenoxaprop-P-ethyl can be studied to confirm its constitution. And we determined that the resistance level might be relevant to the mutation type and mutation frequency. The type of mutation and its frequency in fenoxaprop-P-ethyl-resistant B. syzigachne populations can be confirmed to provide appropriate herbicide management.