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Creation and introduction of new hybrids of sugar sorghum adaptive to arid conditions allow stabilizing and increasing the productivity of forage mass over the years, which is of current importance. The aim of the research was to clarify the scheme and methods of selection of the initial material, assess the level of true heterosis, quantitative traits of green mass yield and plant height in the best obtained hybrids of sugar sorghum. The research was carried out according to the methods of laboratory and field experiments. The scheme of the breeding process included nurseries of source material and breeding nurseries, as well as creation of self-pollinated and sterile lines, hybridization, assessment of samples for CMS, combining ability, and testing new hybrids by saturating crosses and topcross. According to this scheme, sterile lines ‘A-63’, ‘Knyazhna’, ‘Zersta 38A’ were created. By methods of multiple and individual selection with subsequent inbreeding from hybrid populations, fertile paternal forms ‘Stavropolskoe 36’, ‘Galia’ and ‘Larets’ were created. Also, obtained on their basis hybrids ‘Silosnoe 88’ (standard), ‘Alga’, ‘Kalaus’, ‘Yarik’ served as the object of research. On average for 2016–2019, the most significant plant height under the conditions of the “North-Caucasus Federal Agrarian Research Center” was found in late-ripening combinations ‘Yarik’ (301.4 cm) and ‘Kalaus’ (289.0 cm). The level of true heterosis of this trait was 41.7 % and 31.6 %, respectively. In the studied hybrids, the pollination period of the parental forms coincides, the heterosis of the thickness of the stems is observed. The significant leafiness of the plants is also found to be in the late-ripening forms (15.7–16.0 %). The maximum yield of green mass was obtained from hybrids ‘Yarik’ (102.0 t/ha) and ‘Kalaus’ (86.7 t/ha). The level of true heterosis of the studied trait in these combinations was 67.9 t/ha and 47.0 t/ha, respectively, or 66.5 % and 54.2 %. The combination of other genetic plasmas provided a lower level of true heterosis. The late-ripening hybrids ‘Yarik’ and ‘Kalaus’ have significantly higher sugar content in the juice of the stems (12.89–14.03 %) compared with the mid-ripening ‘Silosnoe 88’ (8.9 %) and the medium-late ‘Alga’ (11.14 %). |
