Variability of characteristics valuable for breeding of spring barley

The results of the research (2016–2018) into variability of characteristics of spring barley with the purpose of obtaining the most resistant varieties are presented. The study was conducted in the crop rotation in the breeding nursery of competitive variety testing in the forest-steppe zone of the Republic of Tuva. It was preceded by bare fallow and repeated four times. The soil was dark chestnut, light loamy. The area of the plot registered for the study was 28 m2. Testing, phenological observations, crop records and data processing were carried out in accordance with the approved methodological guidelines. The weather conditions for moisture availability and the average daily temperature regime during the study period varied signi cantly:  in 2016, 2018, which was excessively wet, HTC (hydrothermal coeffcient) was 1.65, 1.90, in moderately humid 2017 HTC equaled 1.36. This made it possible to reliably identify more adapted biotypes of spring barley. In the Republic of Tuva, the yield of spring barley largely depends on the adaptive properties of cultivated varieties and the implementation of the main parameters of the yield structure: the number of productive stems, pieces/m2 (r = 0.726 ± 0.01 ... 0.960 ± 0.266); the mass of 1000 grains, g (r = 0.648 ± 0.179 ... 0.883 ± 0.245). An increase in the number of grains in an ear negatively affects crop yields (r = 0.212 ± 0.058 ... – 0.457 ± 0.126). From the samples of spring barley of Siberian breeding work that were studied in the research, the following samples were identi ed for further breeding for productivity (L 19-101, U 50-3808, U 49-3795); a large number of productive stems (Acha, L 19-101, U 49-3795, U 50-3808); high mass of 1000 grains (Acha, L 19-101, U 50-3808, U 49-3795). These varieties should be included in the cross-breeding adaptive program on the territory of the Republic of Tuva.