Study of the heterosis effect of morpho-biological traits of grain sorghum hybrids F₁

The priority direction in grain sorghum breeding is the development of new early maturing, highly productive hybrids adapted to the soil and climatic conditions of the region and their introduction into agricultural production. Thus, the use of the heterosis effect in hybrids developed from maternal lines with cytoplasmic male sterility is of particular interest. The current paper has presented the study results of heterosis of grain sorghum hybrids of the first generation, developed on the basis of CMS lines, according to the main quantitative traits. The trials were carried out in the laboratory for grain sorghum breeding and seed production of the FSBSI «Agricultural Research Center «Donskoy» in 2020–2022. The purpose of the current research was to study the heterosis effect of morpho-biological traits of grain sorghum hybrids of the first generation developed from crossing sterile lines with highly productive varieties and samples of various breeding. In most hybrids, true and hypothetical heterosis were identified according to plant height, weight, and number of grains per panicle, and the frequency of high heterosis values was estimated according to weight and number of grains. The maximum effect of heterosis manifestation was established based on the trait ‘protrusion of a panicle stalk’ in the combination of AZSK21 x ZSK 24/20 (H true = 335.0 %; H hyp = 694.4%). According to the length of a vegetation period during 2020–2022, all combinations turned out to be early maturing and the heterosis effectwas absent in most variants. 65 % of hybrids were classified as undersized, and the highest heterosis in the trait ‘plant height’ was 38.9 %. During the trials, the hybrid ‘Jetta x ZSK 217’ (87.35 g) showed an excess in the trait ‘grain weight per panicle’ over the best parental form. There have been identified the samples that are expedient to use in crossings to obtain highly productive hybrids, such as ‘By 112’, ‘ZSK 196/17’, ‘ZSK 217’, ‘Zhemchug № 56’, ‘Zhemchug № 59’ and ‘B-10434’.