GENOTYPE BY ENVIRONMENT INTERACTION AND YIELD STABILITY OF BARLEY BREEDING LINES IN MULTI-ENVIRONMENT TRIALS

In modern conditions it is necessary to create varieties of spring barley with combination of high grain yield and stability. For this purpose, multi-environment trials of nine advanced breeding lines and the standard variety Vzirets were carried out in three different ecological zones in Ukraine: Central Forest-Steppe, Polissia and Northern Steppe. High yield variability of spring barley breeding lines has been established. The ANOVA revealed reliable contributions from all three source of the variation: genotype, environment and genotype–environment interaction. The part of influence for environment was the highest – 90.42 %. A set of statistical indices (regression coefficient (bi), deviation mean squares (S²di), variety superiority measure (Pi), nonparametric stability indices (Si^(1) and Si^(2)), homeostaticity (Homi), breeding value (Sci)) and GGE biplot were used to interpret the multi-environment trial data. The applied statistical indices in different ways characterized the investigated barley breeding lines. Some indices estimated the stability only, without considering yield level (S²di, Si^(2)). Other indices were related with the mean yield (Pi), with the maximum (bi) or minimum (Si^(1), Homi, Sci) its value. The combination of statistical indices and graphic model was effective for comprehensive evaluation of the genotype-environment data from multi-environment trials. This approach allows identify the best of the best breeding lines at the final stage of breeding work. The breeding lines Deficiens 5005, Nutans 4855, Nutans 4941 and Nutans 4890 have been submitted to the State Strain Testing of Ukraine as new varieties MIP Visnyk, MIP Ekspert, MIP Myroslav, MIP Vdiachnyi, respectively.