ASSOCIATIVE NITROGEN-FIXATION IN THE RHIZOSPHERE OF DIFFERENT WHEAT SPECIES

The activity of associative nitrogen fixation and its variability was compared for one diploid and eight tetraploid wheat species by the method of acetylene reduction. Polymorphism was revealed in the ability of plants to support nitrogen fixation. The tetraploid species Triticum timopheevii was found to be the most active. The species T. turanicum, T. polonicum, and T. turgidum had low activities, and the soft wheat T. aestivum was medium-active. Single samples with a high significance of the trait were detected among the tetraploid species T. aethiopicum, T. cartlicum, and T. durum. Apparently, genotypes with high associative nitrogen fixation are most common among ancient cultivated wheat species from Asia Minor.