Estimation of adaptability of the maternal lines of the winter rapeseed hybrids bred at the V.S. Pustovoit All-Russian Research Institute of oil crops in the central zone of the krasnodar region, Russia

In 2018-2020, the maternal lines of winter rapeseed, Brassica napus L. developed at the V.S. Pustovoit All-Russian Research Institute of Oil Crops: 1681, 1840-2, 1860, 39712, 39859, 39880, 40059, and 40177 were studied. The purpose of the research was a comparative estimation of the maternal lines of the winter rapeseed hybrids by calculated statistic parameters of adaptability, environmental and genetic plasticity, stability, stress resistance in the central zone of the Krasnodar region in different years. Indicators of environmental plasticity and stability were calculated by seed yield of the maternal lines of the winter rapeseed hybrids for three years due to the procedure by SA Eberhart, WA Rassell as revised by VА Zykin. To calculate a coefficient of a linear regression, the environmental indexes characterizing the variability of lines production conditions were defined. Stress resistance and genetic plasticity were determinated due to the equation by AA Rossielle & J Hamblin. Potential productivity and adaptability were identified by the procedure of LA Zhivotkov. The conditions of the 2020 were satisfactory for winter rapeseed plants growth and development. The average yield of the maternal lines was equal to 4.83 ton ha^-1. The conditions of 2018 and 2019 were not quite favorable, since the environmental index was negative (Ij= -0.14 and -1.23), and average yield was 3.33 and 2.24 ton ha^-1, respectively. The comparative estimation of the maternal lines of the winter rapeseed hybrids developed at the V.S. Pustovoit All-Russian Research Institute of Oil Crops by the parameters of the ecological plasticity and stability in the Krasnodar region showed that the line 39712 having the average seed yield per year of 3.70 ton ha^-1 combines a high level of plasticity, adaptability, stability and is characterized by a high genetic plasticity. This line possesses high responsibility to the advanced cultivation conditions. The line 39880 with the average yield of 3.57 ton ha^-1 also is characterized by environmental and genetic plasticity and adaptability. The lines 39859 and 40177 demonstrated the highest stability and resistance to the stress factors of environments. They are very adaptive to deterioration of the weather conditions. The selected maternal lines are very interesting for breeding of winter rapeseed hybrids of the Russian origin.