Synthetic hexaploids are bridges for transferring new genes that determine resistance to stress factors from wild-type species to bread wheat. In the present work, the method of developing the spring...

The article is devoted to the review and analysis of varietal resources of soft spring wheat cultivated in the conditions of Western Siberia. For 2020, 261 varieties of this crop are included into the State Register of the Russian Federation, including 97 varieties (36.8 %) created by breeders of 15 institutions in the West Siberian region. In the Omsk region, depending on the climatic zone, the largest areas are occupied by the following varieties: mid-early – Omskaya 36 (242.16 thousand hectares), Pamyati Azieva (59.94 thousand hectares), Boevchanka (48.27 thousand hectares), Novosibirskaya 31 (36.3 thousand hectares); mid-season – Omskaya 38 (82.91 thousand hectares), OmGAU 90 (52.84 thousand hectares), Sigma (49.99 thousand hectares), Altaiskaya zhnitsa (35.2 thousand hectares); mid-late – Uralosibirskaya (145.72 thousand hectares), Melodiya (59.53 thousand hectares), Omskaya 28 (57.41 thousand hectares), Pavlogradka (67.31 thousand hectares), Element 22 (65.87 thousand hectares), Omskaya 35 (41.7 thousand ha). The joint creation of varieties with scientists from the Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences made it possible to use, along with collection samples and selection varieties, alloplasmatic introgressive lines of soft wheat carrying the cytoplasm of the cultivated barley Hordeumvulgare L. As the result, there have been developed Sigma, Uralosibirskaya 2, Ishimskaya 11 and Sakmara varieties with a high level of resistance to stem and leaf rust and a medium level to powdery mildew. Due to the massive increase of the leaf and stem rust, varieties with a high level of resistance to these pathogens have been created and recommended for cultivation – Omskaya 38, Sigma, Uralosibirskaya, Uralosibirskaya 2 and Element 22. In the main grain-growing soil-climatic territories of the Omsk region, 15 droughts have been recorded over the past 45 years. Thus, a method for in vitro testing of drought resistance has been developed. Varieties with increased drought resistance and high level of stem rust resistance (Omskaya 37, Omskaya 38, Uralosibirskaya and Omskaya 42) in drought-specific and epiphytotic 2020 exceeded the standard varieties by 0.90-1.74 t / ha in yield. Of special interest among new varieties are Omskaya 42, Uralosibirskaya 2, OmGAU 100, Stolypinskaya 2, Lider 80 and Omskaya 44. It is concluded that close cooperation with Institutes of the Russian Academy of Sciences and other scientific institutions is necessary in order to create varieties that combine increased productivity with resistance to unfavorable biotic and abiotic environmental factors.

Alloplasmic lines are formed when the cytoplasm of one species is replaced by the cytoplasm of another as a result of repeated recurrent crosses of wide hybrids with the paternal genotype. Since the cytoplasm replacement results in new intergenomic interactions between a nucleus and cytoplasm leading to variability of plant characteristics, alloplasmic lines with restored fertility can be an additional source of biodiversity of cultivated plants. Earlier, recombinant alloplasmic lines (H. vulgare)-T. aestivumdesignated as L-17(1)–L-17(37) were formed from a plant with partially restored fertility of the BC3 generation of barley-wheat hybridH. vulgare(cv. Nepolegayushchii) ×T. aestivum(cv. Saratovskaya 29). This male-sterile hybrid was consistently backcrossed with wheat varieties Mironovskaya 808 (twice) and Saratovskaya 29, and Mironovskaya 808 had a positive impact on the restoration of fertility. This paper presents the results of investigation into a group of recombinant alloplasmic lines (L-17F4), as well as into doubled haploids (DH) lines – alloplasmic DH-17-lines obtained from anther culture of alloplasmic lines (L-17F2). The most productive of these lines were used as initial breeding genotypes. Hybrid form Lutescens 311/00-22 developed from the crossing of the alloplasmic DH(1)-17 line (as maternal genotype) with euplasmic line Com37 (CIMMYT), the source of the 1RS.1BL wheat-rye translocation, proved to be successful for breeding. The presence of the 1RS.1BL translocation in the genome of the Lutescens 311/00-22 form and the L-311(1)–L-311(6) alloplasmic lines isolated from it did not lead to a decrease of fertility or sterility in the plants. This indicates that the chromosome of the 1BS wheat does not carry the gene(s) that determine the restoration of fertility in the studied (H. vulgare)-T. aestivumalloplasmic lines. Alloplasmic lines L-311(1)–L-311(6) showed their advantage in comparison with the standard varieties for resistance to leaf and stem rust, yield, and grain quality. The breeding tests performed at Omsk Agricultural Scientific Center, Agrocomplex “Kurgansemena”, Federal State Unitary Enterprise “Ishimskoe” (Tyumen Region), using alloplasmic lines L-311(5), L-311(4) and L-311(6) resulted in varieties of spring common wheat Sigma, Uralosibirskaya 2 and Ishimskaya 11, respectively.

One of the limitations in obtaining the genetic diversity of doubled haploid (DH) lines via anther culture is the development of families of regenerants, and each family represents a clone. This work examines the results of studying this phenomenon in anther culture of alloplasmic (H. vulgare)–T. aestivum and euplasmic lines with 1RS.1BL and 7DL-7Ai translocations and hybrids between them. Parameters of androgenesis such as the number of embryo-like structures, the total number of regenerants, and the number of green regenerants per 100 anthers varied depending on the genotype. In all genotypes from embryo-like structures, predominant development of families of plantlets rather than single plantlets was found. The source of family plantlets was polyembryos. About 75% of families consisted of regenerants at the same fertility level. On average, 37.74%4% of the R0 plants were fertile. The sister DH lines of three hybrid combinations were formed from seeds of R1 plants (2n = 42) with high fertility and in the presence of wheat–alien translocations. After four years of breeding trials, the sister DH lines of three families with fungal disease resistance increased yield, and some parameters of grain quality exceeding the controls were identified as promising for breeding.

Wide hybridization is an important factor of angiosperm speciation and provides an introgression of genes between species. In experimental conditions, wide hybridization is used to increase the genetic diversity of cultivated plants. Since the emergence of reproductive barriers is of great importance for speciation, plants’ capacity for wide crosses is determined by the possibility of overcoming these barriers. This review discusses the main types of incompatibility in wide crossing plants, as well as the factors and methodological approaches that contribute to overcoming them. The role of Kr genes, which determine incompatibility between wheat and rye, is one of the examples of a prezygotic isolation mechanism. Postzygotic incompatibility may be associated with a highly pronounced genetic and epigenetic variability induced by wide crossings. The early stages of the postzygotic period are crucial for developing hybrid seeds due to an embryo’s death, including those associated with uniparental chromosome elimination in hybrid cells and abnormal development of the endosperm. The depression and lethality of F₁ hybrids may be the result of interaction between complementary genes, which cause hybrid necrosis, hybrid chlorosis, and hybrid dwarfness. The causes of hybrid sterility are discussed. Nuclear-cytoplasmic interactions are regarded as one of the mechanisms of incompatibility in wide crosses. Reciprocal hybrids and alloplasmic lines are the main models for studying cytoplasm effects and nuclear-cytoplasmic interactions. Problems concerning work with their models are emphasized. There are some examples underlying the fact that alloplasmic lines are not a plain combination of the nuclear genome and cytoplasm of different species. The development of alloplasmic lines is connected with the structural and functional variability of nuclear and organelle genomes.

Individual plants from the BC₁F₆ and BC₁F₈ backcross progenies of barley-wheat [H. marinum subsp. gussoneanum Hudson (=H. geniculatum All.) (2n = 28) × T. aestivum L. (2n = 42)] and the BC₁F₆ progeny of their amphiploids were used to obtain alloplasmic euploid (2n = 42) lines L-28, L-29, and L-49 and alloplasmic telocentric addition (2n = 42 + 2t) lines L-37, L-38, and L-50. The lines were examined by genomic in situ hybridization (GISH), microsatellite analysis, chromosome C-banding, and PCR analysis of the mitochondrial 18S/5S repeat. Lines L-29 and L-49 were characterized by substitution of wild barley chromosome 7H¹ for common wheat chromosome 7D. In line L-49, common wheat chromosomes 1B, 5D, and 7D were substituted with homeologous barley chromosomes. Lines L-37, L-38, and L-50 each contained a pair of telocentric chromosomes, which corresponded to barley chromosome arm 7H¹L. All lines displayed heteroplasmy for the mitochondrial 18S/5S locus; i.e., both barley and wheat sequences were found.