Agriculture and livestock breeding are branches, which determine the economic structure of Stara Zagora district. In the last years the stock breeding in the district has marked progress, and the product quality has been improved and stabilized in quantitative aspect. There are milk and meat processing companies, situated in Stara Zagora district, which work for the European market. The purpose of this paper is to investigate the competitiveness and adaptability to the European market of the stock-breeding branch in Stara Zagora district. In order to achieve this goal, the following tasks have to be solved: -to analyze the condition of the stock-breeding branch in Stara Zagora district; -to examine the trends in the development of the stock-breeding branch; -to analyze the possibilities for sale of the animal products on the European market. The following methods are applied in order to achieve this goal and to solve the tasks such as analysis and synthesis, a systematic approach, a structural approach, statistical methods.

The research was carried out with the aim of comparative assessment of varieties and selected forms of sour cherries by the chemical composition of fruits to identify the best genotypes with their subsequent use in breeding, as well as industrial, farm and collective gardening. The experiments were carried out in 2016–2019 in triplicate. The garden was laid out in 2004-2005 and is located in the southwestern part of the Republic of Tatarstan. The material for the study was 20 varieties and selected hybrids of sour cherries of different ripening periods of the breeding of Tatar Research Institute of Agriculture. On average, over the years of research in fruits of different varieties, the content of soluble solids varied within 16.69 ... 26.49%, sugars - 3.72 ... 6.35%, organic acids - 0.96 ... 2.64%, vitamin C - 11.70 ... 15.90 mg per 100 g. The variability of the content of soluble solids and vitamin C was average (V = 15.1 ... 19.3 and 10.3 ... 14.3%, respectively). The amount of sugars, organic acids and the sugar acid index changed more significantly - V = 20.9… 25.2, 22.0… 25.8 and 29.0… 37.7%, respectively. The genotype had a greater influence on the variability of the content of soluble dry substances, sugars and organic acids in sour cherry fruits (30.2 ... 65.9%) than the conditions of the year (3.0 ... 24.7%) and the interaction of these factors (11.4 ... 29.2%). A positive relationship was noted between the content of soluble solids in fruits and the sugar-acid index (r = 0.85), the content of sugars (r = 0.76), acids (r = 0.50), the sum of positive summer temperatures (r = 0.69 ); an insignificant negative relationship with vitamin C (r = -0.45) and summer precipitation (r = -0.60). Sources of a high content of soluble solids in fruits (21.84 ... 26.49%) in the breeding can be Shelangovskaya, Pamyat Sakharova, Sevastyanovskaya varieties, selected forms - Chereshnevaya No. 1, 1-11-31, 80-8, 1-10 -30 and 37-8; high content of vitamin C (15.16 ... 15.90%) - varieties Shelangovskaya, Low-growing and selective form Chereshnevaya No. 1. In industrial, farm, collective gardening it is recommended to use varieties Shelangovskaya, Pamyat Sakharova, Sevastyanovskaya.

Пленарные доклады 1Казанский институт биохимии и биофизики -обособленное структурное подразделение ФИЦ КазНЦ РАН, Казань, Россия 2Казанский (Приволжский) федеральный университет, Казань, Россия, 3Федеральное государственное бюджетное учреждение науки Институт биохимии и физиологии растений и микроорганизмов РАН, Саратов, Россия, 4Институт органической и физической химии им. А.Е. Арбузова -обособленное структурное подразделение ФИЦ КазНЦ РАН, Казань, Россия

The purpose of the research was to analyze the work on the creation of new varieties of apple, cherry and plum, carried out from 1938 to 2020 in the Tatar Research Institute of Agriculture, as well as the identification of promising crossbreeding combinations and genotypes for use in breeding and transfer to the State variety testing. In the apple breeding orchard, promising seedlings in hybrid families were identified by productivity, taste and size of fruits: Anis Novy×Plodovitoe (1-6-48), Anis Novy×Vityaz(1-7-26, 1-7-27,  1-7-57,1-7-70, 1-7-97), Anis Novy×Ural Souvenir (1-8-88) . In 2021, 4 apple varieties were entered into the State Register of Breeding Achievements of the Russian Federation: Renet Tatarsky, Volzhskaya Krasavitsa, Tenkovskaya and Kamskaya. The apple variety Renet Povolzh’ya is undergoing state variety testing. Promising hybrids 1-1-11, 1-2-11, 1-2-14, 1-10-30, 1-11-6, 1-11-31, 2-2-75,2-2-93 have been selected in sour cherry breeding orchards. In 2015, a new self-fertile variety of Shelangovskaya sour cherry was accepted for State variety testing in the Middle Volga and Volga-Vyatka regions. In 2021, 8 varieties of sour cherries were included in the State Register of Breeding Achievements of the Russian Federation: Krasa Tataria, Zarya Tataria, Shakirovskaya, Truzhenitsa Tataria, Sevastyanovskaya, Tveritinovskaya, Pamyat Sakharova and Obilnaya. In the plum breeding orchard promising hybrid seedlings 1-1-11, 1-1-20, 1-1-47, 1-1-75, 1-1-84, 1-2-36, 1-2-49, 1-2-57, 1-2-60, 1-3-19, 1-3-58, 1-3-86, 1-8-43 and others were selected according to important economic and biological characteristics. In 2021, the State Register of Breeding Achievements of the Russian Federation, admitted for use, included 8 varieties of home-breeding plums of the Tatar Research Institute of Agriculture: 2 varieties of early ripening — Sverkh Rannya, Sineokaya; 6 varieties of medium ripening — Rakitovaya, Renklod Tenkovskiy, Volzhanka, Tenkovskaya Golubka, Kazanskaya and Pamyat Khasanova.