The inheritance of glyphosate-resistant goosegrass was studied by making reciprocal crosses between resistant (R) and susceptible (S) biotypes. Eighty-four F1 hybrids were confirmed using isozyme analyses. Reciprocal F1 hybrids displayed uniform levels of resistance intermediate (I) to that of the parental types, with no indication of maternal inheritance. The F1 hybrids were selfed to produce F2 populations. F3 populations were produced by selfing resistant and intermediate F2 phenotypes. A segregation ratio of 1:2:1 (S:I:R) was observed in the F2 and subsequently in the F3 generations derived from selfing intermediate F2 phenotypes. Individuals in F3 families derived from selfing resistant F2 phenotypes were resistant. Results from the present study show that glyphosate resistance in goosegrass is inherited as a single, nuclear, and incompletely dominant gene.
