A rapid test for detection of tribenuron-methyl resistance in sunflower

A rapid laboratory test for detection of tribenuron-methyl resistant sunflower genotypes was developed. Four homozygous and four heterozygous tribenuron-methyl resistant hybrids, as well as a susceptible one were grown on MS medium supplemented with different concentrations of herbicide (2.0 µM, 2.5 µM, 3.0 µM, 3.5 µM and 4.0 µM) and with pH either 7 or 8. The effect of medium pH and herbicide concentration on above-ground part and root mass of sunflower seedlings was observed. The test enabled visual discrimination between resistant and susceptible genotypes in 5 days, and discrimination between homozygous and heterozygous resistant genotypes in 12 days. All tested herbicide concentrations and morphological parameters were found to be suitable for discrimination of tribenuron-methyl susceptible genotypes. The best pH and herbicide concentration combination and morphological parameter for discrimination between homozygous and heterozygous resistant sunflower genotypes were 3.0 µM at pH 7 and root mass, respectively.