ADAPTIVE TRAITS AND THEIR MANIFESTATION IN ALFALFA POPULATIONS OF THE SECOND YEAR FOR FODDER USE

Abstract

The purpose of research. Study of adaptive traits in breeding populations of alfalfa for fodder use in the second year of life and selection of promising material for further use in the breeding process. Materials and methods. Research was conducted at the Institute of Irrigated Agriculture of the National Academy of Sciences of Ukraine during 2018–2020 pp. The object of study was 24 alfalfa populations. The analysis of the resistance of alfalfa genotypes to stress was carried out using the index of environmental conditions, regression coefficient, predicted ecological stability, plasticity of the variety under different ecological gradients, indicators of stress resistance and genetic flexibility, homeostatic parameters and selection value, adaptability coefficient, general adaptive capacity, variances of specific adaptive capacity, relative stability of the genotype, selection value of the genotype, coefficients of nonlinearity and compensation-destabilization. The results. On grass alfalfa of the second year of life, the value of the environmental index (lj) under conditions of natural moisture in 2018 was -0.97, in 2019 it was -1.79, and in 2020, the worst year for growing alfalfa, it was -6.11. During irrigation in 2019 and 2020, the indices of environmental conditions (lj) were +1.83 and +1.36, respectively, and it was the highest (+5.67) in 2018. According to eight parameters of adaptability, the population of was selected as the most stable to drought M.g. / CP-11, after six – Ram. d. and five – M.g. / M.agr. According to the parameters of adaptability, three populations of the intensive type were selected: Prymorka, Sin(s). / Prymorka and V.11 / P. d. and the Prymorka / Sin(s) population, which is plastic in relation to moisture conditions. According to the results of GGE biplot analysis, the most stable populations G12 – Ram were distinguished. d., G14 – T. / Emeraude, d., G17 – M.agr. / C. and G21 – PHNV2. Populations G2 – Elehiya, G4 – M.g. / P.p., G5 – Sin(s). / Prymorka and G13 – (Emeraude / T.)2 and G22 – V.11 / P. d. respond best to improved moisture conditions, but show a sharp decrease in yield under natural moisture conditions. Genotypes G6 – LR / H and G15 – M.g. / CP-11 are characterized by high yield under both moisture conditions, which indicates the plasticity of these populations. Agglomerative hierarchical and k-means cluster analysis of alfalfa populations was conducted and three clusters were identified. Conclusions. The most suitable identifiers of adaptability are highlighted: regression coefficient (bi), homeostaticity (Hom), selection value (Sc), variance of specific adaptive capacity (σ²CAЗi), relative stability of the genotype (sgi), selection value of the genotype (СЦГi), compensation-destabilization coefficient (Kgi), which made it possible to single out valuable breeding samples. The Ram population most adapted to stressful conditions was identified. d. Populations V.11 / P. d. and Sin(s). / Prymorka had signs of being unstable, i.e. picky about growing conditions. The population of M.g. / CP-11 was characterized by high yield under both moisture conditions, which indicates its plasticity.