Root habitus and plant productivity of spring bread wheat synthetic lines in Western Siberia, as connected with breeding for drought tolerance

In Western Siberia, droughtappears duringthe initial period of plant vegetation, and dryness in June and early July is increasing, as evidencedby the hydrothermal coefficients. Improvement of drought tolerance of wheat varieties is a breeding priority for ensuring crop stability over the years of warming and increasing frequency of dry years. This paper is the first our report ofwide surveyed concerning the assessment of phenotypic differences in the main parameters of the root system between hexaploid synthetic wheat lines and their advantage over standard varieties due to the formation of the powerful root system penetrating into deep layers of the soil. The synthetic lines we studied in 2016-2017 in Western Siberia, were created in CIMMYT by crossing of durum wheat ( Triticum durum Desf., genome АВ) varieties Aisberg, Leucurum 84693, Ukr-Od 952.92, Ukr-Od 1530.94 (Odessa,Ukraine) and Рandur (Romania) with different entries of Aegilopstauschii Coss. (synonym Ae. squarrosa, genome D) from Caspian basin...