Phenotypic variability of common wheat (Triticum aestivum L.) breeding lines on yield components under environmental conditions of Western Siberia and Tatarstan

Spring wheat is one of the widely cultivated crops in the Russian Federation. Wheat breeding is aimed at creation of varieties characterized by high productivity and grain quality. When creating new varieties, the main attention is paid to ecological stability to environments, which negatively affects the agromomic traits and yield. Currently there is no enough information on the inheritance and manifestation of productivity traits in various agro-ecological conditions in advanced generations of the crosses between winter and spring wheat varieties. In this study, we analyzed the variability of the yield traits in wheat breeding lines ( Triticum aestivum L.) of F6-7 generations, obtained from hybridization of winter wheat varieties with spring donors of leaf rust resistance genes with the aim to identify promising genotypes as ф source of valuable agronomic traits. Field trials were performed in 2018 in three regions, the Novosibirsk and Omsk region and the Republic of Tatarstan. The following traits were studied: tiller number per plant, the grain number per ear, the grain weight per ear, 1000 grain weight, and the grain weight per plant. Ecological plasticity of the lines was studied using indexes of the intensity and stability. Analysis of variance based on the results of field evaluation indicates a significant influence of the genotype, the environment and their interaction in the phenotypic manifestation of all the studied characters. The highest contribution of the genotype is shown for the grain number per ear (42.8 %) and the 1000 grain weight (57.0 %). A high contribution of environmental factors was found for tiller number (41.8 %) and grain weight per ear (40.3 %). The genotype ½ environment interaction had a significant effect on all traits, its contribution varied from 25.9 % (1000 grain weight) to 41.0 % (grain weight per ear), which indicates a significant response of genotypes to changing climatic factors. The results of field tests showed that there was a high variability of all characters in all three climatic zones, but the degree of variation differed. The averaged indicators of the studied traits were lower in the field conditions of the Omsk zone as compared to the Novosibirsk region and Tatarstan. Higher fluctuations were noted for the grain number per ear (13.0-69.0), the grain weight per ear (0.35-2.65 g), and the grain weight per plant (0.15-6.95) in Tatarstan’s environments in comparison with other regions. The estimation of stability and intensity indices showed that 16 of 55 genotypes have intensive type, 35 were semi-intensive and 4 were extensive. The grouping of samples by the principal coordinate analysis method divided the genotypes into four main clusters according to the stability and intensity parameters. Molecular analysis for the presence of leaf rust resistance genes Lr6Ai#2 , LrAsp5 , and LrTt2 introduced from Thinopyrum intermedium (Host) Barkworth & D.R. Dewey, Aegilops speltoides Tausch and Triticum timopheevii Zhuk., respectively, showed that 10 out of 55 lines do not contain alien genetic material. The results of marker analysis for the presence of resistance genes did not correlate with the clustering of samples by intensity and stability types. This fact suggests that the presence of alien genomes does not influence on the stability of breeding lines. Based on the obtained results, genotypes with valuable characters were selected as sources of productivity.