BREEDING FOR INCREASING IMMUNITY WHEN CREATING NEW SOYBEAN VARIETIES

The purpose of research is to study the immunological properties of the working collection and local soybean samples, to identify the sources of disease resistance in the southern zone of the Amur Region in order to create immune varieties. Phytopathological assessment to determine the degree of resistance to bacteriosis, Septoria blight, Cercospora blight, downy mildew, Phyllosticta leaf blight and root rot under natural infectious background was carried out in 2010–2021, during the period of mass flowering of plants. Excessively wet years (2010, 2013, 2018, 2019, 2020 and 2021) were the most favorable for the development of causative agents of Septoria blight, downy mildew and Cercospora blight. During the study period, the manifestation of Phyllosticta leaf blight and bacteriosis on the studied soybean samples was insignificant, 80 % of the analyzed material was characterized by resistance and low susceptibility to root rot. Based on immunological analysis, genetic sources of resistance were identified: to Septoria blight (24 samples), downy mildew (31 samples), Cercospora blight (29 samples), and root rot (18 samples), a number of which were included in crosses. For the period 2010–2021, with the participation of sources of resistance, 403 hybrid combinations of soybeans were obtained, 27 new highly productive soybean varieties with a high immune status were transferred to the SSI, 18 of which were included in the State Register for use in production. In the nursery of competitive variety testing (KSI), for the three-year period (2019–2021) 8 samples of soybeans were identified – Am.2454, Am.2464 Am.2466, Am.2502, Am.2522, Am.2524, Am.2431, Am.2437, characterized by a high yield of 2.54–2.85 t/ha (0.15–0.27 t/ha to st.), complex resistance to pathogens, which are promising material for creating future varieties.