PLASTICITY AND STABILITY OF SOYBEAN ACCORDING TO SELECTION INDICES

Abstract

The study of the parameters of plasticity and stability of breeding indices, will identify the best forms of soybeans for their targeted use in hybridization in the creation of new varieties. The highest indicators of the selection index (number of seeds / number of beans per plant) were obtained from cultivars: UD0202457 - 1.58; UD0202566 - 1.57; UD0202529 - 1.57; UD0202557 - 1.55. These cultivars in response to the hydrothermal regime were highly plastic (bi> 1) in response to improved cultivation background. It should be noted that these varieties provided a fairly high level of homeostatic, namely UD0202457 - 0.71; UD0202566 - 0.61; UD0202529 - 0.63. the coefficient of variation was low - (V <10%), and the coefficient of agronomic stability was high - 97.8 and 97.4 and 97.5%. We established a correlation between the coefficient of plasticity and the selection index (number of seeds / number of beans per plant), where the correlation coefficient r = 0.491, which indicates the average strength of the correlation. That is, these varieties, despite the low absolute value of the selection index provided a stable implementation of quantitative variability, which is less dependent on the hydrothermal regime of years of research. According to the selection index (number of beans per plant / number of productive nodes) soybean cultivars were distinguished: UD0202557 - 2.06; UD0200773 and UD0202468 - 2.05, these varieties were highly plastic (bi> 1) in response to changes in hydrothermal growing conditions. The stability variance (Si2) in these soybean cultivars is as close as possible to zero. The coefficients of agronomic stability were also high, which varied from 92.8 to 94.9%. However, the highest indicators of homeostaticity were provided by soybean cultivars, which were characterized by a low response to changes in the growing cultivation background (bi <0): UD0200983 - 0.72; UD0202529 - 0.71; UD0202457 - 0.59 and UD0202563 - 0.74. These cultivars were characterized by the lowest coefficients of variation, which varied from 2.7 to 3.4% and the highest coefficients of agronomic stability from 96.6 to 97.3%.