Cross-and Multiple Herbicide Resistant Lolium rigidum Guad. (Rigid Ryegrass) Biotypes in Iran

Weed competition, especially from grass species, is estimated to cause ۲۳% reduction in yield in the wheat fields of Iran. During the years ۲۰۱۳ to ۲۰۱۶, a study was conducted to evaluate the resistance to herbicides of ۳۰ rigid ryegrass (Lolium rigidum) biotypes that had been collected from wheat fields of Khuzestan Province. The screening of these biotypes was conducted with clodinafop-propargyl in the greenhouse and revealed biotypes with a survival rate of greater than ۲۰% in response to this herbicide. These biotypes were further studied for the evaluation of cross and multiple resistance. A total of ۹۴ and ۷۵% of the rigid ryegrass biotypes showed resistance to ACCase- and ALS-inhibitors, respectively. Approximately ۶۹% of the rigid ryegrass biotypes included individuals with resistance to at least two herbicide mechanisms of action. This is the first report of cross and multiple resistance in rigid ryegrass biotypes from Iran. The leaves of the rigid ryegrass biotypes cross-resistance to ACCase-inhibitors were analyzed using CAPS and dCAPS markers to identify probable amino acid substitutions at ۲,۰۴۱, ۲,۰۸۸, ۱,۷۸۱, and ۲,۰۷۸ positions on the ACCase gene. In two and nine biotypes, mutations were observed in the ۱,۷۸۱ and ۲,۰۴۱ positions, respectively. These results indicated that there is a serious problem with herbicide resistance in rigid ryegrass, including cross and multiple resistance, and a need to implement long-term integrated management strategies.

کلیدواژه ها:

ACCase inhibitors ، ALS inhibitors ، CAPS markers ، dCAPS markers ، Mutation. ، بازدارنده های استیل کو آنزیم آ ، بازدارنده های استولاکتات سینتاز ، مارکر CAPS ، مارکر dCAPS ، چچم یکساله