Natural and Induced Glufosinate-resistance in selected Rice (<em>Oryza sativa L</em>.) Varieties in Sri Lanka

Abstract

Purpose: Herbicide-resistant rice varieties in combination with post-emergent broad-spectrum herbicides improve the eff ectiveness of weed management in rice fi elds. Herbicide-resistance can be acquired naturally or induced by classical or modern breeding techniques. In the present study, screening of Sri Lankan rice varieties to glufosinate was examined and attempts were made to develop glufosinate-resistant rice varieties with the help of the breeding technique, mutagenesis. Research Method: Natural glufosinate-resistance was studied in seven (7) traditional and eighteen (18) inbred rice varieties under 0.27, 0.30 and 0.33 kg ha-1 glufosinate concentrations. Induced glufosinateresistance in seed-derived calli of four glufosinate-susceptible rice varieties using Ethyl Methane Sulfonate was also observed and these were then treated with 0.2% (v/v) glufosinateto to determine induced glufosinate-resistance in seed-derived calli. Findings: Two traditional varieties (Pachchaperumal, Ma Wee) and fi fteen inbred varieties (At362,