Development of F₁ hybrids of cabbage with complex resistance in the south of Russia

Relevance Breeding for resistance is one of the priorities when working with late-ripening cabbage.The most significant damage to this crop in the south of Russia is caused by diseases such as fusarium, black rot, and from pests – tobacco trips. Methods The purpose of the research is development of heat-resistant hybrids of medium-late and late maturity of various areas of use with complex resistance. For 2 decades much attention was paid to breeding and immunological work on development of inbred lines with group resistance: to fusarium and polygenic resistance to black rot. The study of race-specific resistance for better protection against black rot began in 2013. At that, the progeny of the lines were eveluated, which were selected by hydathogenic polygenic resistance on the infectious background of cabbage during inoculation of plants with the Krasnodar population of the pathogen.Since specific resistance to a particular race inherited in white cabbage is recessive and it is very difficult to develop lines and hybrids resistant to several races, a strategy was chosen to increase resistance to this dangerous disease based on a combination of field resistance, stem resistance to the main race 1 and leaf resistance to one or two races. Results As a result of the work carried out in 2018, 44 lines of medium-late maturity with stem resistance to race 1 were selected, of which a significant part of the lines had leaf resistance to a particular race, including 4 lines resistant to races 1 and 4, 1 line – to races 0, 1,4, and 1 line – to races 0, 3, 4. The heat-resistant hybrid for processing Sudarynya was passed to State Variety Testing, it has one parent with stem resistance to race 1, leaf resistance to races 0, 1.4 and hydatode resistance, and the second parent has stem resistance to race 1 and hydatode resistance. Every year, hybrids are evaluated for thrips damage. According to the results of the evaluation of hybrids, lines with a high tolerance to tobacco thrips were identified. In 2017-2018 9 lines with complex resistance to fusarium, black rot and thrips (Ten211, Yas111, Eubi122, Hn861, Hn270-21, Hn270-24, Br272-22, Hn270-14p-1, 272-510) were selected, on the basis of which promising combinations of economically valuable traits were obtained.