Early diagnostics of bread winter wheat varieties for drought tolerance

Abstract

Purpose. To conduct assessment of bread winter wheat varieties for resistance to osmotic stress and to identify the most resistant genotypes to moisture deficiency in the early stages of vegetation. Methods. The experiments were carried out in 2016 and 2017, according to methodical recommendations of All-Union Institute of Plant Industry (ed. by V. F. Dorofeyev, 1974). Drought tolerance of 56 bread winter wheat varieties of various geographical origins was analyzed by previously disinfected seed germination (during 7 days at temperature of 20–21 °C) on solutions with sucrose concentrations corresponding to 16 and 18 atm of osmotic pressure. The varieties studied were differentiated by the ability of 7-day seedlings to form 3, 5 or other number of primary embryonic roots. Seeds sprouted under similar conditions on distilled water were the control. Results. A number of varieties were identified that significantly exceeded the standard variety Podolianka by the proportion of sprouted seeds on sucrose solutions, including the varieties MIP Kniazhna, Rozkishna and Horlytsia myronivska. On average over the years of research, germination ability of these varieties was 86, 79, 82 % and 78, 66, 55 %, respectively at 16 and 18 atm. On the 7th day of germination the varieties studied have formed mainly 3 or 5 primary roots. Seeds of the varieties of Myronivka breeding formed usually 3 embryonic roots, more than 60 % of the standard variety Podolianka seeds had 5 roots. Conclusions. According to the percentage of seeds germinated on osmotic solutions of different concentrations (16 and 18 atm), drought tolerance ranks for 56 wheat varieties of bread winter wheat of different geographical origin were determined. The Ukrainian varieties MIP Kniazhna, MIP Valensiia, Horlytsia myronivska, Rozkіshna, Statna, Shchedra nyva, and Zіra had high indices of seed germination on sucrose solutions, which significantly exceeded the standard. The varieties Hordovyta, Statna, Podolianka were distinguished by high percentage of seeds with 5 embryonic roots. Thus, the possibility of diagnosing drought tolerance of winter wheat varieties according to the indices of seed germination on sucrose solutions and to the number of primary roots formed on the early stages of seed germination has been shown.