Development and characterization of a line with substitution of chromosome 4B of wheat Triticum aestivum L. on chromosome 4Hmar of wild barley Hordeum marinum ssp. gussoneanum (4x)

Introgressive hybridization is the main method of broadening the genetic diversity of bread wheat. Wild barley Hordeum marinum ssp. gussoneanum Hudson (2n = 4x = 28) has useful agronomical traits, such as high resistance to stress factors, that could be a potential source of new genes for bread wheat improvement. This study aimed to evaluate the possibility of introgression of H. marinum chromosomes into the genome of bread wheat using an incomplete amphiploid H. marinum ssp. gussoneanum (4x)-T. aestivum (Pyrotrix 28) (2n = 54) carrying the cytoplasm of wild barley. For this purpose, we crossed the line of bread wheat variety Pyrotrix 28 with an incomplete amphiploid, and then selected cytogenetically stable 42-chromosome plants with a high level of fertility in hybrid progeny. Genomic in situ hybridization (GISH) revealed a pair of H. marinum chromosomes in the genome of these plants. C- banding analysis confirmed that bread wheat chromosome 4B was replaced by wild barley chromosome 4Hmar. SSR markers Xgwm368 and Xgwm6 confirmed the absence of chromosome 4B, and EST markers BAWU808 and BAW112 identified chromosome 4Hmar in the genome of the isolated disomic wheat-barley substitution line. The study of this line showed that the substitution of chromosome 4B with chromosome 4Hmar resulted in a change of some morphological traits. It included intense anthocyanin coleoptile coloration, specific for H. marinum, as well as a lack of purple coloration of the ears in the leaf sheath, specific for Pyrotrix 28. Line 4Hmar(4B) showed increased performance for several traits, including plant height, number of spikes and tillers per plant, spikelet and grain number in the main spike, grain number per plant, but it had decreased values of 1000-grain weight compared to wheat. Cytogenetic stability and fertility of line 4Hmar(4B) indicated a high compensation ability of barley 4Hmar for wheat chromosome 4B and confirmed their homeology.

Creation and study of emmer (Triticum dicoccum) × triticale hybrids

Triticale (× Triticosecale Wittmack) is of great interest as an insurance crop that can ensure the stability of the gross harvest of feed and food grains at a lower cost. In Western Siberia, only winter triticale varieties are cultivated, however, spring triticales are important for cultivation in regions not suitable for winter crops. To create spring varieties with high yields and good grain quality, it is necessary to study and enrich the gene pool, identify donors of economically valuable traits. One of the possible ways to solve this problem can be through the production of secondary hexaploid triticales with the involvement of the tetraploid wild-growing species of emmer wheat Triticum dicoccum (Schrank) Schuebl. The aim of this work was to create and study hybrids of emmer T. dicoccum (Schrank) Schuebl. with hexaploid triticale using genomic in situ hybridization for staining of meiotic chromosomes and analysis of plant productivity elements in F4-F8. DT4, DT5, DT6 plants and the prebreeding F6 forms obtained from them - DT 4/168, DT 5/176 and DT 6/186 - were selected according to the characteristics of the productivity and the nature of the grain in the F4 hybrid population. The offspring of hybrids DT4 and DT5 and prebreeding forms DT 4/168 and DT 5/176 had an increased grain nature (over 750 g/l), but low productivity. The hybrid DT6 and the breeding form DT 6/186 obtained from it had high grain productivity (785 ± 41 and 822 ± 74 g/m2, respectively), but, like the paternal form of triticale UK 30/33, had a reduced nature of the grain. In F8 DT 6/186 plants, 7 homologous pairs of rye chromosomes and from 27 to 30 wheat chromosomes were found in meiosis, which indicates the presence of a complete rye genome and two wheat ААВВ genomes. Rye chromosomes showed stable formation of bivalents in contrast to wheat chromosomes, which caused the presence of aneuploids in plant populations. Thus, hexaploid forms DT 4/168 and DT 5/176 with well-made smooth grain and high grain size were obtained, which can be used as a source of this trait for selection of food-grade triticale. DT 6/186 is a promising form for further breeding in order to obtain high-yielding forms of triticale.

The Effect of Chromosome Arm 1BS on the Fertility of Alloplasmic Recombinant Lines in Bread Wheat with the Hordeum vulgare Cytoplasm

The genetic mechanisms of fertility restoration in alloplasmic bread wheat with the barley cytoplasm are poorly explored. The effect of the 1BS chromosome arm on the fertility of bread wheat with the H. vulgare cytoplasm was studied depending on the incompleteness/completeness of the cytonuclear compatibility. (i) Three self-fertile (SF) lines and one partially fertile (PF) line with an incomplete cytonuclear compatibility and (ii) four self-fertile (SF) lines with a complete cytonuclear compatibility were studied. For the lines in group (i), the heteroplasmy (simultaneous presence of barley and wheat copies) of the 18S/5S mitochondrial (mt) repeat was revealed as well as the barley-type homoplasmy of chloroplast simple sequence repeats (cpSSRs). In the lines in group (ii), the 18S/5S mt repeat and cpSSRs were found in the wheat-type homoplasmic state. In all of the lines, the 1BS chromosome arm was substituted for the 1RS arm. The F1 plants of SF(i)-1BS × 1RS hybrids were fertile. The results of a segregation analysis in the F2 plants of SF(i)-1BS × 1RS showed that 1BS carries a single dominant fertility restorer gene (Rf) of bread wheat with the H. vulgare cytoplasm. All of the F1 plants of PF(i)-1BS × 1RS hybrids were sterile. A single dose of this restorer gene is not sufficient to restore fertility in this alloplasmic PF(i) line. All of the F1 and F2 plants of SF(ii)-1BS × 1RS hybrids were self-fertile.

Study of Androgenic Plant Families of Alloplasmic Introgression Lines (H. vulgare) -T. aestivum and the Use of Sister DH Lines in Breeding

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.

The creation and characterization of the bread wheat line with a centric translocation T2DL.2RL

The development of bread wheat introgressions with alien genetic material from cultural and wild Triticeae species is an effective method for expanding the wheat gene pool necessary for breeding. To date, numerous collections of introgressions as substitutions and chromosome modifications have been obtained; however, the creation and study of wheat with new valuable traits still remain an important line of research. Rye Secale cereale L., whose chromosomes carry genes that control valuable economic and biological characteristics and properties, is widely used to produce new wheat forms. In this study, a wheat-rye translocation obtained by backcrossing the wheat-rye disomic-substitution line 2R(2D)1 with the variety Novosibirskaya 67 was characterized. The chromosomal composition of karyotypes was studied using fluorescent in situ hybridization and C-banding. Two centric translocations, derived from two long arms of chromosomes 2D and 2R, T2DL.2RL, were identified, the remaining 40 wheat chromosomes did not undergo modifications. Meiosis in the lines was stable. Chromosomes T2DL.2RL formed bivalents in all meiocytes, which confirmed their homology. The morphological characteristics of the spike in the T2DL.2RL line and Novosibirskaya 67 did not differ. A comparative analysis of productivity between the T2DL.2RL translocation line and the parental forms, Novosibirskaya 67 and the 2R(2D)1 line, was carried out. The T2DL.2RL line is inferior to Novosibirskaya 67 in all characters with different confidence levels. The productivity characters of the 2R(2D)1 line exceeded or did not differ from those of T2DL.2RL, however, the mass of 1000 grains was significantly lower. The results showed the effect of the T2DL.2RL translocation on the trait “plant height”. This character was significantly lower than that of Novosibirskaya 67 in two vegetation periods. Consequently, the T2DL.2RL translocation reduces plant height and productivity.