Differentiating ability of environmental conditions and estimation of spring durum wheat varieties according to ‘falling number'

The purpose of the current study was to identify the differentiating ability of environmental conditions and estimate spring durum wheat varieties developed by the Samarsky RIA according to a falling number (FN). There were studied 19 varieties and 3 breeding lines, representing 3–6 breeding stages. According to the chronology of deve- lopment, breeding lines belong to the 6th stage. Data on the Bezenchukskaya 139 variety were used as a standard. The study was carried out in the steppe zone, on heavy loamy chernozems of the experimental plot of the Samarsky RIA in 2018–2023. FN was determined on grain samples taken from 2 repetitions on the Hagberg-Perten device “Falling Number”. In 2023, the factor ‘environment’ was represented by four backgrounds: 1) grain samples 1 month after harvesting at full maturity; 2) grain samples a month after harvesting with a dead-ripe stage of 7 days; 3) grain of the first option after 6 months of storage; 4) grain harvested at the moment of maturing and moistened after 6 months of storage. There were calculated genotype variances, environment, their correlation, parameters of general (GACi), specific (CACi), relative adaptability (Sgi), breeding value of a genotype (GBVi), linearity coefficients (Lgi), genotype compensation (Kgi), parameters of the environment differentiating ability (EDAk) and its relative value (Sek), typicality coefficients (ttk), environment predictability (Pk). There was established that FN was affected by a genotype with a share of 6,01 %, by environment with a share of 72,24 % and by a genotype-environment correlation with a share of 16,86 %. The best genotypes in terms of SVGi, taking into account the GACi parameters, include the following: Marina (GACi = 10,3, SVGi = 228,7), 2084D-6 (GACi = 41,8, SVGi = 208,6), Bezenchukskaya Yubileinaya (GACi = 25,8, SVGi = 211,8), Bezenchukskaya Zolotistaya (GACi = 11,7, SVGi = 221,7). For the standard, these parameters were GACi = -27,0, SVGi = 205,6. Among the 6 studied backgrounds by DCEk (182–241), Sek coefficient (42–90), Kek coefficient (3,26–5,71), 5 analyzing backgrounds and one stabilizing one were identified, distinguished by high estimates of typicality (ttk = 0,83) and predictability (Pk = 0,32), which allows predicting the response of varieties in the system of environments. In general, the environmental conditions of the experimental field of the Samara Research Institute of Agriculture, which have been developing over several years, form a fairly effective system of backgrounds for the selection and stabilization of the "falling number" trait of spring wheat durum.