Genotypic effects on the response of soybean ( <i>Glycine max</i> (L.) Merrill) to sulfonylurea herbicides

Sulfonylurea (SU) herbicides registered for use in other crops Australia may leave residues the soil interrupting rotations involving soybean. However, two unlinked genes (ALS1 and ALS2) confer SU tolerance Here, we report experiments that explored effectiveness of these ALS Australian soybean germplasm. The first assessed to halosulfuron-methyl or metsulfuron-methyl lines with either zero gene (ALS1) both ALS1 ALS2 five different genetic backgrounds. presence conferred strong at herbicide application rates as high four times (4×) recommended field rate, evidence interaction background; carrying only also performed well but demonstrated less tolerance. For third experiment, homozygous were intercrossed a half-diallel mating design. resulting F2 population screened herbicide. In all instances, provided absolute protection growth tip. Analyses seedling dry weight purple leaf discoloration significant differences among crosses. weight, heritability estimates indicated additional variation 10 crosses (p ≤ 0.05). results three studies confirm when crossed into germplasm, suggest possible epistatic effects within backgrounds, possibility (minor) conferring