ASSESSMENT OF THE ADAPTIVE POTENTIAL OF PEAR VARIETIES IN THE CONDITIONS OF THE STEPPE ZONE OF THE SOUTHERN URALS

Abstract

The article presents the results of studying the adaptive potential of promising pear varieties of domestic breeding in the conditions of the steppe zone of the Southern Urals (Orenburg region). The aim of the work was a comparative assessment of pear varieties with different ecological origins in terms of yield, ecological plasticity and stability. The research was carried out in 2018–2020 on the experimental plot of 2002 planting of the Orenburg branch of the Federal Horticultural Research Center for Breeding, Agrotechnology and Nursery. The objects of research were promising varieties of pears of domestic breeding Pingvin, Permyachka, Sverdlovchanka, Isetskaya Sochnaya, Lel, Povislaya, Uralochka, Chizhovskaya, Samara Krasavitsa, Gvidon, Lada. The check variety was the variety Krasnobokaya (K). The agro-climatic conditions in the years of research were diverse, which allowed us to reliably assess the adaptability of the studied varieties. The studies were carried out in accordance with generally accepted methods. The parameters of ecological plasticity and stability (bi, Si2) were calculated according to the method S. A. Eberhart and W. A. Russell as presented by V. A. Zykin et al. The method is based on the calculation of linear regression (bi), which characterizes the ecological plasticity of the variety, and the mean square deviation from the regression lines (Si2), which determines the stability of the variety under environmental conditions. Statistical processing of the obtained data was carried out by the method of variance analysis according to Dospekhov B. A. using the analysis package Microsoft Office Excel 10. As a result of the conducted research, it was revealed that the highest yield in the conditions of the steppe zone of the Southern Urals on average over the years of research were intensive varieties: Pingvin (6.6 t/ha; bi = 1.22), Sverdlovchanka (7.5 t/ha; bi = 1.25), Lel (8.4 t/ha; bi = 1.79); environmentally plastic varieties Isetskaya Sochnaya (8.1 t/ha; bi =1.1), Lada (7.4 t/ha; bi = 0.57), as well as the neutral variety Povislaya (6.9 t/ha; bi = 0.33). At the same time, all varieties showed high environmental stability.