Genetic Analysis of Glufosinate Resistance in Crosses Between Transformed Rice (Oryza sativa) and Red Rice (Oryza sativa)

Reciprocal controlled crosses were made in the greenhouse between Gulfmont rice transformed with the bialaphos resistance (BAR) gene and red rice and BAR-transformed Koshihikari rice and red rice to assess the inheritance of glufosinate resistance. All F 1 plants were resistant to 2.2 kg ai/ha glufosinate. Ammonia accumulation as a measure of glufosinate resistance in the F 1 hybrids was assayed at 4 and 8 days after treatment (DAT). Ammonia accumulation in hybrids 4 DAT was similar to glufosinate treated, transformed rice, while treated nontransformed plants accumulated 14 to 23 times more ammonia compared with the hybrids. The nature of inheritance of glufosinate resistance in F 2 rice plants was studied by a glufosinate dip test, a spray test, and ammonia assay. All three tests confirmed that glufosinate resistance, as influenced by the BAR gene, segregated in a 3 (resistant): 1 (susceptible) ratio.