摘要
[Objectives]This study was conducted to detect the evolution of resistance to glyphosate in Eleusine indica.[Methods]In the previous study,glyphosate-resistant population T2-4 was screened out from E.indica populations in sugarcane fields in Guangxi.In this study,we determined the resistance index of T2-4 by whole plant bioactivity assay and further explored the molecular biological mechanism of resistance.[Results]The resistance index of T2-4 was 112,and it is thus a highly resistant population.Amino acid mutations were found at positions 102,106 and 381 in the EPSPS sequence of T2-4,containing at least a triple mutation allele in Thr-102-Ile,Pro-106-Ser and Pro-381-Leu and a double mutation allele in Pro-106-Ser and Pro-381-Leu.qPCR was used to determine the EPSPS gene copy number and expression in resistant plants of T2-4.EPSPS gene copy number and expression both increased,with 8.3-fold higher copy number and 2.7-fold higher expression than the sensitive population.Therefore,the resistance of T2-4 to glyphosate was mainly caused by multiple target mechanisms including mutation of EPSPS gene,copy number increase and expression increase,and the resistance of E.indica to glyphosate needs our high attention.[Conclusions]At present,the level of resistance to glyphosate is very high in the sugarcane fields of Guangxi,and it is necessary to take a variety of weed control measures to solve the problem of glyphosate resistance.
