Water scarcity has a significant impact on plants, quality and quantity of crops. On the soils of the northeast of European Russia, instability of precipitation is one of the main factors negatively affecting barley productivity. To assess the drought tolerance level, we used the RSR (root-to-shoot ratio) indicator, which shows the relative redistribution of fluxes of plastic substances between root and aerial organs. Evaluation of 57 collection accessions of spring barley of various ecological and geographical origins was carried out. As a result of the research, sources of breeding of valuable traits were identified for further breeding work on the creation of barley varieties adaptive to the conditions of the Volga-Vyatka region. The accessions Bonita, Bionic, Cooper, Danuta, 752A, NCL 95098, local sample from India (k-3506), Odessky 115, Rodos, Kazminsky, Polarny 14, Adam, Bear, Medicum 11, Irbe (PR-3528), Mie, 121–13, and C-105 are characterized by resistance to osmotic stress at the early stages of organogenesis. For further breeding work drought-resistant varieties NCL 95098, Cooper, Bonita, Danuta, Mie, Rodos, Kazminsky, Adam, Bear, Medicum 11, Irbe (PR-3528), 752A, Polarny 14, and C-105, distinguished by the elements of plant productivity, are advisable to use taking into account their positive qualities. The rest of the drought-resistant accessions are recommended to be included in crosses with varieties having higher productivity.

Variation in contents of chlorophyll and carotenoid pigments and their correlation links with elements of yield structure of 17 samples of spring barley (Hordeum vulgare L.) was estimated by method of spectrophotometric analysis of acetone extracts from flag and second leaves. The variability of chlorophyll a content was 13.3%, of chlorophyll b – 13.5%, and carotenoids – 14.4% for flag leaf, and respectively 11.6%; 10.8%; 11.2% - for second leaf. Practically there was no variation in distribution of pigments between light-harvesting complexes (LHC) and reaction centers (RC) of photosystems (the average value of a part of chlorophyll in a light-harvesting complex was 81% of its total amount at a variation of 2.8%). The flag leaf pigments’ content was not correlated with final productivity of barley plants (r ≤ 0.27) whereas for a second leaf it is revealed statistically significant (at p ≤ 0.05) interrelation between productivity and content of chlorophyll a (r = 0.64), chlorophyll b (r = 0.58), and carotenoids (r = 0.60). It is disclosed that in the studied set of spring barley samples, one can predict extent of the level of the next parameters: “ear length”, “grain mass per ear” and “1000-grains mass” by the pigments content in a flag leaf; and the parameters “ear length” and productivity – by its content in a second leaf. Among three analyzed photosynthetic pigments, yellow pigments (carotenoids) render the greatest influence on the level of development of separate elements of yield structure. Content of pigments in a second leaf is more suitable index for assessment of potential productivity of spring barley cultivars. Breeding work on increase of carotenoids and/or chlorophyll b contents in a second leaf is perspective.

Based on the statistical assessment of long-term field studies, in competitive variety tests, barley cultivars were identified adaptive to the conditions of the region, promising for transfer to the State variety test. As a result of the studies, a promising breeding material was created. The efficiency of using various methods of creating a new initial material, in particular, the cell culture method, is shown. A statistically significant correlation was established between the value of the hydrothermal coefficient (GTK) in the period “leaf tube formation - heading” and the yield capacity of a cultivar (r = 0.520). High variability (V = 24.4%) in the duration of the inter-stage period “leaf tube formation - heading” was revealed in the cultivars of competitive variety testing. Cultivars 94-13 and 38-15 are distinguished by a high yield potential (up to 6.4… 6.9 t/ha) and the duration of inter-stage periods, at which the main stages of organogenesis occur at the most favorable combination of heat and moisture for the potential development of plant features and properties. Cultivars 207-15, 38-15, and regenerant 550-08, characterized by high annual average yield capacity (5.9…5.7 tons/ha) and adaptability, are promising for transfer to the Russian Federation State variety test.