Genotypic differences in reaction of barley root system on Mn and Fe toxicity O.A. Simonova, E.M. Lisitsyn, E.V. Tovstik and M.V. Simonov E3S Web Conf., 217 (2020) 09013 Published online: 14 December 2020 DOI: 10.1051/e3sconf/202021709013