Ecological stability and plasticity of spring brown mustard variety of VNIIMK breeding

Analysis of ecological plasticity and stability must be a base in the development of new genotypes of spring brown mustard. The purpose of the research was a comparative characteristic of spring brown mustard cultivars bred at the V.S. Pustovoit All-Russian Research Institute of Oil Crops by calculated statistic parameters of adaptability, ecological plasticity, stability, stress-resistance, and genetic flexibility in the central zone of the Krasnodar region in 2018-2022. We studied commercial (Nika, Yunona, Gorlinka, Galateya) and promising (VN-11/18, VN-27/18, VN-9/18, and VN-25/18) cultivars. The indicators of ecological plasticity and stability were calculated basing on seed yield of spring brown mustard cultivars for five years by a methodology of Eberhart S.A., Rassell W.A. as reworded by Zykin V.A. To calculate a coefficient of a linear regression, we determined environment indexes, which characterized variability of conditions of the cultivar cultivation. The stress-resistance and genetic flexibility were determined by an equation of Rossille A.A., Hamblin J. as presented by Goncharenko A.A. The potential productivity and adaptability were revealed by a methodology of Zhivotkov L.A. The weather conditions in 2020 and 2021 were the most favorable, environmental index had the highest positive meaning and was equal to 1.74 and 1.82 under the highest average yield of brown mustard, which was equal to 1.92 and 1.93 t/ha, respectively. The weather conditions of 2018 and 2022 were less favorable for estimation of brown mustard samples ( Ij = -1.71 and -2.00). A comparative analysis of brown mustard cultivars bred at the V.S. Pustovoit All-Russian Research Institute of Oil Crops by parameters of ecological plasticity and stability in the Krasnodar region showed the cultivars Yunona, VN-27/18, and VN-11/18 had the highest plasticity, and Yunona and Galateya demonstrated the highest stability and adaptability to declining of cultivation conditions. Thus, the cultivars Yunona and Galateya were characterized with high yield, plasticity, stability, genetic flexibility, and adaptability. In contrast conditions, the promising cultivar VN-9/18 had high indicators of resistance to stress factors, yield, and adaptability coefficient.