Introgressive Forms Research Articles

Possibilities of using the tetraploid interspecific hybrid <i>Hordeum bulbosum</i> L. × <i>Hordeum vulgare</i> L. in obtaining new recombinant barley lines

Background. Hordeum bulbosum L. is the only wild species of the genus Hordeum, the gene pool of which is successfully used in introgressive hybridization to increase the genetic diversity of H. vulgare L. When creating introgression forms based on hybrids of H. vulgare with H. bulbosum, it is necessary to take into consideration the ploidy of the parent species, and their genetic features that determine the intensity of the process of H. bulbosum chromosomes elimination in embryogenesis. The purpose of our investigation was to study the features associated with the elimination of bulbous barley chromosomes in embryos obtained in various combinations of crosses involving the tetraploid hybrid H. bulbosum with H. vulgare for its effective use in obtaining introgression lines of H. vulgare. Material and methods. The analysis was performed on 9-15 days old embryos obtained in crosses of the tetraploid hybrid F2 (H. bulbosum A17 (4x) × H. vulgare ‘Borwina’ (4x)) (HbHbHvHv) with ‘Igri’ (2x) and ‘Borwina’ (2x) barley varieties, with H. bulbosum A17 (4x), as well as during its self-pollination. The chromosomal composition of embryos of different ages was analyzed on squashed embryo slides using genomic in situ hybridization (GISH). Results. Among the 11-15 days old embryos obtained from self-pollination of the hybrid, approximately half of the studied ones were mixoploids, while in other embryos the majority of cells contained only the genomic material of H. vulgare. The elimination process was very intensive in crosses of the hybrid with the barley varieties ‘Igri’ (2x) and ‘Borwina’ (2x), and by day 10-11 after pollination cells containing only the genomic material of H. vulgare predominated in all embryos, regardless of the direction of crossing and the variety used. Hybrid embryos with a stable chromosomal composition resulted from a cross of a tetraploid hybrid with H. bulbosum A17 (4x). Embryos with recombinant H. vulgare chromosomes carrying alien genetic material of bulbous barley were identified in all types of crosses. Conclusion. The most efficient way for the mass production of introgression lines of cultivated barley varieties based on the partially fertile hybrid F2 (H. bulbosum A17 (4x) × H. vulgare ‘Borwina’ (4x)), is the crossing with varieties of H. vulgare (2x). The progeny from such crosses will contain only cultivated barley plants, among which it is possible to identify forms with the introgression of H. bulbosum and use already the first generation from their self-pollination for selecting H. vulgare lines carrying the genetic material of bulbous barley in both homologs.

Creation and analysis of the starting material obtained by hybridisation of Triticum spelta L. × Triticum compactum Host.

In the conducted studies, as a result of the hybridisation of Triticum spelta L. × Triticum compactum Host. several new forms were obtained that differ in morphobiological and economically valuable traits. The research aims to expand the genetic diversity of spelt wheat and to obtain new introgressive forms with a high level of manifestation of economically valuable traits. The following methods were used: field, laboratory, hydrological analysis, and statistical analysis. As a result of the research, new source material was obtained and valuable genotypes with a unique combination of genetic material of the source species were identified. An intermediate type of inheritance of plant morphology traits (plant height, ear length and density, grain weight per ear) in F1 hybrids was established. In F2 hybrids, a split of 3:1, indicates the dominant monogenic nature of inheritance. The shape of the ear is inherited monogenically by the type of incomplete dominance. The analysis of transgressive variability in F3-4 hybrids Triticum spelta L. × Triticum compactum Host. shows that the highest proportion of positive transgressions was recorded for the number of spikelets (28.1-28.5%) and grains (23.4-51.0%) in the ear and grain weight per spikelet (20.3-32.1%). The analysis of stability and adaptability indices allowed us to distinguish line 201, characterised by high stability (S2 di=0.027), homeostasis (Hom=193.3) and breeding value (Sc=3.9), and line 206, combining high yield (5.11 t/ha) with high homeostasis (Hom=182.3) and breeding value (Sc=3.9). The introgressive hybridisation with Triticum compactum Host. identified new genetic sources characterised by the presence of deficient traits for breeding and of great practical importance for further breeding and genetic improvement of spelt, as they can enrich the existing gene pool of the crop

Visualizing Chromosome Territories and Nuclear Architecture of Large Plant Genomes Using Alien Introgressions.

Visualization of chromosome territories is a challenging task in plant genomes due to the lack of chromosome-specific probes, especially in species with large genomes. On the other hand, combination of flow sorting, genomic in situ hybridization (GISH), confocal microscopy, and employment of software for 3D modeling enables to visualize and characterize chromosome territories (CT) in interspecific hybrids. Here, we describe the protocol for the analysis of CTs in wheat-rye and wheat-barley hybrids, including amphiploids and introgression forms, where a pair of chromosomes or chromosome arms from one species is introgressed into the genome of another species. In this way, the architecture and dynamics of CTs in various tissues and different stages of cell cycle can be analyzed.

Metabolism of crown tissue is crucial for drought tolerance and recovery after stress cessation in Lolium/Festuca forage grasses.

A process of plant recovery after drought cessation is a complex trait which has not been fully recognized. The most important organ associated with this phenomenon in monocots, including forage grasses, is the crown tissue located between shoots and roots. The crown tissue is a meristematic crossroads for metabolites and other compounds between these two plant organs. Here, for the first time, we present a metabolomic and lipidomic study focused on the crown tissue under drought and recovery in forage grasses, important for agriculture in European temperate regions. The plant materials involve high (HDT) and low drought-tolerant (LDT) genotypes of Festuca arundinacea, and Lolium multiflorum/F. arundinacea introgression forms. The obtained results clearly demonstrated that remodeling patterns of the primary metabolome and lipidome in the crown under drought and recovery were different between HDT and LDT plants. Furthermore, HDT plants accumulated higher contents of primary metabolites under drought in the crown tissue, especially carbohydrates which could function as osmoprotectants and storage materials. On the other hand, LDT plants characterized by higher membranes damage under drought, simultaneously accumulated membrane phospholipids in the crown and possessed the capacity to recover their metabolic functions after stress cessation to the levels observed in HDT plants.

Creation and breeding value of introgressive forms, obtained by hybridizations of Triticum Spelta L. × Triticum turgidum subsp. dicoccum (Schrank ex Schübl.) Thell.

The aim of the research was to expand the genetic diversity of spelt wheat by introgression of genetic material of the species Triticum turgidum subsp. dicoccum (Schrank ex Schübl.) Thell. and to create on this basis new source material. Materials and methods. The study was conducted during 2016–2022 in the conditions of Uman National University of Horticulture, located in the zone of the Right-Bank Forest-Steppe of Ukraine, in the subzone of unstable moisture. The source material was winter spelt wheat variety Zoria Ukrainy (maternal form) and the sample Triticum turgidum subsp. dicoccum (Schrank ex Schübl.) Thell. (pollinator). The research used the common technology of growing winter cereals. Sowing was carried out in the optimal time for the zone – the third decade of September. All records and observations were performed in accordance with generally accepted methods. In work was used a systematic method of plot placement with four repetitions. Results. As a result of the conducted researches a number of introgressive lines of spelled wheat with different level of manifestation of morphological and economically valuable features was created. The created samples according to the morphology of the ear are divided into morphotypes of spelt, emmer and intermediate forms. Conclusions. As a result of the conducted researches the technology of creation of initial breeding material at distant hybridization of Triticum spelta L. × Triticum turgidum var. dicoccoides. Valuable high-yielding samples were obtained using introgressive breeding. It was found that the highest frequency of transgression in the second and third generations was recor­ded by the weight of grain from the ear (19.1–20.0%). Materials with a yield (535.2 g/m2) and a weight of 1000 grains (44.8 g) significantly exceeded the standard (sample 230), as well as protein (20.4%) and gluten (44.0%) significantly exceeded the standard (sample 227). The selected samples will be used by donors of genes of econo­mically valuable traits in breeding schemes for the creation source material of spelt wheat.

New introgressive forms of cultivated barley obtained on the basis of interspecific hybrids <i>Hordeum vulgare</i> L. × <i>Hordeum bulbosum</i> L.

Background. The use of alien genetic material of bulbous barley Hordeum bulbosum L. to increase the diversity of cultivated barley Hordeum vulgare L. is an important task, since H. bulbosum is characterized by a number of valuable traits. One of the ways to use the genetic potential of bulbous barley is the interspecific hybridization and obtaining fertile introgressive lines of H. vulgare based on interspecific hybrids. The aim of the study was to obtain new introgressive forms of spring barley using interspecific triploid (HvHbHb) and tetraploid (HbHbHvHv) hybrids of cultivated barley with bulbous barley to expand the collection of introgressive lines of H. vulgare. Materials and methods. To create new introgressive forms, diploid barley H. vulgare (2x) cv. ‘Roland’, was crossed with interspecific hybrids H. vulgare cv. ‘Roland’(2x) × H. bulbosum W851 (4х) (HvHbHb), and H. bulbosum A17 (4x) × H. vulgare ‘Borwina’ (4x) (HbHbHvHv). Cultivated barley forms with introgression of the bulbous barley genetic material were selected from the offspring from these crosses; then the selection was continued in two progenies from self-pollination of selected BC1 plants with three alien introgressions. Identification and localization of introgressions was carried out using the method of fluorescent in situ hybridization (GISH and FISH with chromosome-specific markers). Results. The crossing of cultivated barley with triploid and tetraploid interspecific hybrids H. vulgare × H. bulbosum yielded new forms of cultivated barley with recombinant chromosomes, among which two plants with three terminal introgressions of the genetic material of bulbous barley were identified. The first plant, derived from a triploid hybrid, showed introgressions in chromosomes 5HL, 1HL and 3HS. When two homologues with the 5HL introgression of the initial size are combined in the karyotype, the lethality of seedlings is observed in the offspring plants. In the second plant obtained on the basis of a tetraploid hybrid introgression was revealed in chromosomes 5HL, 2HL, and 7HS. In the offspring from self-pollination of this form, the presence of the 2HL introgression of the original size in both homologues led to plant sterility. Forms with a change in size of the introgression in 5HL and 3HS in the offspring of the first plant and with a change in size of the introgression in 2HL in the offspring of the second plant were detected, which indicated that meiotic recombination had occurred in those chromosome regions in BC1 plants. Conclusions A barley plant with the introgression of bulbous barley chromatin into chromosomes 1HL, 5HL, and 3HS of cultivated barley was identified in the offspring from a cross of cultivated barley with a triploid interspecific hybrid H. vulgare × H. bulbosum. In crosses with a tetraploid interspecific hybrid, a barley plant with the introgression into chromosomes 2HL, 5HL, and 7HS was found. On the basis of ‘Roland’ spring barley cultivar, two series of new introgressive forms of H. vulgare with various combinations of recombinant chromosomes have been created.

The Role of Triacylglycerol in the Protection of Cells against Lipotoxicity under Drought in Lolium multiflorum/Festucaarundinacea Introgression Forms.

Triacylglycerol is a key lipid compound involved in maintaining homeostasis of both membrane lipids and free fatty acids (FFA) in plant cells under adverse environmental conditions. However, its role in the process of lipid remodeling has not been fully recognized, especially in monocots, including grass species. For our study, two closely related introgression forms of Lolium multiflorum (Italian ryegrass) and Festuca arundinacea (tall fescue), distinct in their level of drought tolerance, were selected as plant models to study rearrangements in plant lipidome under water deficit and further re-watering. The low drought tolerant (LDT) form revealed an elevated level of cellular membrane damage accompanied by an increased content of polyunsaturated FFA and triacylglycerol under water deficit, compared with the high drought tolerant (HDT) form. However, the LDT introgression form demonstrated also the ability to regenerate its membranes after stress cessation. The obtained results clearly indicated that accumulation of triacylglycerol under advanced drought in the LDT form could serve as a cellular protective mechanism against overaccumulation of toxic polyunsaturated FFA and other lipid intermediates. Furthermore, accumulation of triacylglycerol under drought conditions could serve also as storage of substrates required for further regeneration of membranes after stress cessation. The rearrangements in triacylglycerol metabolism were supported by the upregulation of several genes, involved in a biosynthesis of triacylglycerol. With respect to this process, diacylglycerol O-acyltransferase DGAT2 seems to play the most important role in the analyzed grasses.

Cytogenetic insights into Festulolium

Climate change calls for new methods and plant materials to breed crops adapted to new environmental conditions. Sustainable forage and amenity grass production during periods of severe drought and heat waves during summer, and unequal distribution of precipitation over the year will require drought-tolerant genotypes. However, high-yielding ryegrasses (Lolium spp.), which are the most commonly used grass species, suffer during abiotic stresses. Introgression of drought and heat tolerance from closely related fescues (Festuca spp.) offers an opportunity to develop superior hybrid cultivars to mitigate the negative impact of climate change. Intergeneric cross-hybridization and the development of Festulolium (Festuca × Lolium) hybrids was initiated 100 years ago and resulted in registration of almost one hundred cultivars. For a long time, their genome composition was not known and was debated by breeders and geneticists. In the last three decades, molecular cytogenetic and genomic approaches have enabled their detailed characterization. These studies revealed a gradual replacement of Festuca chromosomes by those of Lolium in consecutive generations leading to an almost complete elimination of Festuca chromatin in the introgression forms. On the other hand, amphiploid cultivars seem to be more stable with the optimal proportions of the Lolium to Festuca genomes at about 2:1. In this mini review, we discuss recent advances in the analysis of the genome composition of Festulolium hybrids with a specific focus on genome (in)stability.

Interspecific Hybridization and Introgression Influence Biodiversity—Based on Genetic Diversity of Central European Viola epipsila-V. palustris Complex

The Viola epipsila-V. palustris complex is a highly taxonomically complicated group of species in its entire circumboreal range of distribution. Habitat loss, forest flooding, and hybridization could lead to the extinction of V. epipsila. A hybrid index and principal component analysis (PCA) were used to select qualitative and quantitative morphological features to distinguish parent species and hybrids, inter simple sequence repeat (ISSR) markers to determine the genetic diversity of the populations, flow cytometry to estimate the genome size (GS), and non-coding chloroplast DNA (cpDNA) regions to indicate the directions of crosses. All taxa are very morphologically variable, and their features can change within a season. The most stable feature is the distance of the bracts on the pedicel from the rhizome. The genetic diversity of all taxa populations is low and highly influenced by selfing and vegetative propagation. The population structure is differentiated: populations of V. epipsila or V. palustris, mixed populations with both parent species, F1 hybrids and populations with introgressive forms occur in different regions. The interspecific GS variation corresponds to the ploidy level (4x = 2.52 pg, 8x = 4.26 pg, 6x = 3.42 pg). Viola epipsila is the mother plant of the hybrids. Research has shown the risk of V. epipsila extinction in Central Europe and the importance of local populations in studying the role of hybridization in reducing/maintaining/increasing biodiversity.

Freezing Tolerance of Lolium multiflorum/Festuca arundinacea Introgression Forms is Associated with the High Activity of Antioxidant System and Adjustment of Photosynthetic Activity under Cold Acclimation.

Though winter-hardiness is a complex trait, freezing tolerance was proved to be its main component. Species from temperate regions acquire tolerance to freezing in a process of cold acclimation, which is associated with the exposure of plants to low but non-freezing temperatures. However, mechanisms of cold acclimation in Lolium-Festuca grasses, important for forage production in Europe, have not been fully recognized. Thus, two L. multiflorum/F. arundinacea introgression forms with distinct freezing tolerance were used herein as models in the comprehensive research to dissect these mechanisms in that group of plants. The work was focused on: (i) analysis of cellular membranes’ integrity; (ii) analysis of plant photosynthetic capacity (chlorophyll fluorescence; gas exchange; gene expression, protein accumulation, and activity of selected enzymes of the Calvin cycle); (iii) analysis of plant antioxidant capacity (reactive oxygen species generation; gene expression, protein accumulation, and activity of selected enzymes); and (iv) analysis of Cor14b accumulation, under cold acclimation. The more freezing tolerant introgression form revealed a higher integrity of membranes, an ability to cold acclimate its photosynthetic apparatus and higher water use efficiency after three weeks of cold acclimation, as well as a higher capacity of the antioxidant system and a lower content of reactive oxygen species in low temperature.

Adjustment of Photosynthetic and Antioxidant Activities to Water Deficit Is Crucial in the Drought Tolerance of Lolium multiflorum/Festuca arundinacea Introgression Forms

Lolium multiflorum/Festuca arundinacea introgression forms have been proved several times to be good models to identify key components of grass metabolism involved in the mechanisms of tolerance to water deficit. Here, for the first time, a relationship between photosynthetic and antioxidant capacities with respect to drought tolerance of these forms was analyzed in detail. Two closely related L. multiflorum/F. arundinacea introgression forms distinct in their ability to re-grow after cessation of prolonged water deficit in the field were selected and subjected to short-term drought in pots to dissect precisely mechanisms of drought tolerance in this group of plants. The studies revealed that the form with higher drought tolerance was characterized by earlier and higher accumulation of abscisic acid, more stable cellular membranes, and more balanced reactive oxygen species metabolism associated with a higher capacity of the antioxidant system under drought conditions. On the other hand, both introgression forms revealed the same levels of stomatal conductance, CO2 assimilation, and consequently, intrinsic water use efficiency under drought and recovery conditions. However, simultaneous higher adjustment of the Calvin cycle to water deficit and reduced CO2 availability, with respect to the accumulation and activity of plastid fructose-1,6-bisphosphate aldolase, were clearly visible in the form with higher drought tolerance.

Mechanisms of drought resistance in introgression forms of Lolium multiflorum/Festuca arundinacea

Drought resistance in plants can be associated with four different strategies to cope with water stress. These strategies are classified as drought escape, avoidance, tolerance, and recovery. The expression of each strategy depends on plant species and its genetic potential, but also on the environmental conditions, including the stress intensity and duration. Often, prolonged drought conditions are associated with drought escape or avoidance, whereas short but severe drought periods induce drought tolerance. To analyze the components of drought resistance in forage grasses, we applied two Lolium multiflorum/Festuca arundinacea introgression forms into a comprehensive research. Obtained results clearly show that the response of plants to severe short term drought conditions with limited rhizosphere did not reflect their response to long progressive drought conditions, which did not limit root growth. The BC4-INT-40 introgression form with extensive and deep roots was characterized by a more efficient drought avoidance and regeneration mechanisms under long-term drought, whereas the BC4-INT-66 form with shorter roots revealed a lower productivity and re-growth capacity under the prolonged drought. On the other hand, this form had also a better photosynthetic performance under short and intensive drought conditions with a limited space for root development.

Is the presence of simple or glandular hairs a good trait for distinguishing species in Caryophyllaceae? A case study of Arenaria serpyllifolia sensu lato in southern Poland

The presence of different types of indumentum is regarded as a valuable taxonomic trait for describing and differentiating between species in many different families and genera. In Caryophyllaceae, however, this character is sometimes a subject of discussion and scientific conflicts. For instance, within <em>Arenaria serpyllifolia</em> sensu lato (s. l.), two or three taxa have been distinguished based on the presence or absence of glandular and/or eglandular hairs on the calyx and uppermost leaves, namely <em>A. serpyllifolia</em>, <em>A. viscida</em>, and <em>A. serpyllifolia</em> var. <em>intermedia</em>. The most common, based on material from Poland, is the glandular morphotype of <em>Arenaria serpyllifolia</em> s. l. (315 specimens), which is in contrast to the eglandular and intermediate morphotypes represented by 174 and 24 specimens, respectively; however, the ranges of distribution of these morphotypes fully overlap. Based on our macro- and micromorphological examination of specimens belonging to the group, as well as numerical and molecular studies, we conclude that the occurrence and abundance of eglandular and glandular hairs may vary in particular parts of specimens of <em>Arenaria serpyllifolia</em> s. l., i.e., on their calyces, bracts, and uppermost and middle cauline leaves. The width of the capsule was the only character for which significant differences between the SERP and VIS morphotypes were found; however, considering all studied morphotypes together, the capsule characters overlap considerably. Moreover, morphological variation expressed by different types of indumenta is not paralleled by internal transcribed spacer (ITS) polymorphism patterns. The probable lack of genetic barriers between populations of individuals with glandular or eglandular hairs supports the hypothesis that the type of indumentum is of minor taxonomic importance. However, it is possible that we are dealing with sampling in the hybrid zones of both taxa, and that individuals demonstrating morphological traits typical of both taxa (eglandular and glandular) do not in fact represent pure taxa but only different kinds of hybrids, backcrosses, or introgressive forms.

Structural and metabolic alterations in root systems under limited water conditions in forage grasses of Lolium-Festuca complex

Drought resistance is a crucial attribute of plants and to properly decipher its mechanisms, a valuable plant model is required. Lolium multiflorum is a forage grass characterized by a low level of abiotic stress resistance, whereas Festuca arundinacea is recognized as a species with drought resistance, including both stress avoidance and tolerance strategies. These two species can be crossed with each other. Two closely related L. multiflorum/F. arundinacea introgression forms with distinct levels of field drought resistance were involved, thus enabling the dissection of this complex trait into its crucial components. The processes occurring in roots were shown to be the most significant for the expression of drought resistance. Thus, the analysis was focused on the root architecture and the accumulation of selected hormones, primary metabolites and glycerolipids in roots. The introgression form, with a higher resistance to field water deficit was characterized by a deeper soil penetration by its roots, and it had a higher accumulation level of primary metabolites, including well recognized osmoprotectants, such as proline, sucrose or maltose, and an increase in phosphatidylcholine to phosphatidylethanolamine ratio compared to the low resistant form. A comprehensive model of root performance under water deficit conditions is presented here for the first time for the grass species of the Lolium-Festuca complex.

Experimental evidence for selection against hybrids between two interfertile red oak species

Abstract Reproductive isolation between related oak species within one taxonomic section is incomplete. Even though pre- and post­zygotic isolation mechanisms have been described for interfer­tile oak species, natural hybridization is common in contact zones between related oaks. The apparent restriction of inter­specific hybrids between ecologically divergent species to intermediate environments in contact zones suggests postzy­gotic isolation via environmental selection against hybrids in parental environments. Overrepresentation of hybrids in seeds as compared to adult trees provides additional indirect evi­dence for selection against hybrids. Here, we used genetic assignment analyses in progeny obtained from a sympatric stand of Quercus rubra and Quercus ellipsoidalis, two interfertile species with different adaptations to drought, to characterize the number of hybrids and “pure” species in the non-germinated acorns and in seedlings. The occurrence of 43.6 % F1 hybrids and introgressive forms among the non-germinated acorns and their very low frequency in the seedlings (9.3 %) is to our knowledge the first direct evidence for early selection against hybrids in oaks possibly as result of genetic incompatibilities. Additionally, we found a signature of positive selection on EST-SSR PIE200 in Q. rubra which needs further confirmation. These results contribute to our under­standing of reproductive isolation and divergence between interfertile oak species with different ecological adaptations.

Leaf morphological and genetic variation between Quercus rubra and Quercus ellipsoidalis: comparison of sympatric and parapatric populations

Species boundaries in oaks are often not clear-cut, which is potentially a result of interspecific hybridization with trait introgression and phenotypic plasticity. Quercus rubra L. and Quercus ellipsoidalis E.J. Hill are two interfertile partially sympatric red oak species (section Lobatae) with different adaptations to drought. Quercus ellipsoidalis is the most drought tolerant of the North American red oak species and is characterized by deep tap roots, a shrubby growth and by deeply dissected leaves. Genetic differentiation between species is low for most molecular markers. However, one genic microsatellite in a CONSTANS-like (COL) gene, FIR013, was previously identified as outlier locus under strong divergent selection between species. In this study, we analyzed leaf morphometric traits in neighboring (parapatric) Q. rubra/Q. ellipsoidalis populations and in one sympatric population from the same region along an environmental gradient. Using multivariate statistics of leaf traits both species showed distinct bimodal frequency distributions for the first canonical discriminant function with some overlap in the phenotypic extremes, especially in the sympatric population. Leaf dissection traits showed strong and consistent differentiation between species in sympatric and parapatric populations, while differentiation for leaf size was lower in the sympatric population under more similar environmental conditions. Leaf phenotypes in F1 hybrids and introgressive forms suggested maternal effects and introgression of leaf traits between species. The association of outlier gene copy number at FIR013 with species-discriminating leaf traits in Quercus rubra can be a reflection of population differences since outlier gene copy number and population membership show significant collinearity. Similar environmental selection pressures on outlier alleles and leaf shape could also have resulted in this association. In future studies, segregating full-sib families could be used to test whether outlier alleles and associated genomic regions are indeed associated with leaf traits or other species-discriminating characters.

Wheat chromosome instability in the selfed progeny of the double monosomics 1Rv-1A

Structural alterations of chromosomes are often found in wheat-rye hybrids. In the majority of cases modifications are observed for rye chromosomes, yet chromosome aberration cases are described for wheat, including the progeny of Triticum aestivum disomic and monosomic addition lines. Since wheat-rye substitution and translocation lines are the source of rye chromatin in wheat breeding programs, the information on possible chromosome changes in the genomes of introgressive forms is important. Chromosome behavior in F1 meiosis and chromosomal composition of F2 karyotypes for double monosomics 1Rv-1A were studied by applying C-banding, genomic in situ hybridisation (GISH) using rye genomic DNA, and sequential in situ hybridization using repetitive sequences pAs1, pSc119.2 and centromere specific pAet-06 as probes. The double monosomics 1Rv-1A were obtained by crossing of disomic substitution line with chromosome 1A replaced by Secale cereale 1Rv in the bread wheat Saratovskaya 29 (S29) background with S29. The results indicated a high frequency of bipolar chromosome 1Rv orientation, as compared to 1A, at metaphase I (MI) (58.6 and 34.7 % of meiocytes, respectively), and, at anaphase I (AI), chromatid segregation of 1Rv compared to 1A (70.53 and 32.14 % of meiocytes, respectively). In few cases desynapsis of wheat homologues was observed, at AI, the chromosomes randomly distributed between the poles or underwent chromatid segregation. At AI, the two wheat homologues separated onto sister chromatids in 10.89 % of cells.The plants F2 karyotypes were marked with aneuploidy not only of chromosomes 1A and 1Rv, but also of 1D, 2D, 3D, 3B, 3A, 4A, 6D, 6B, 6A, and 7D. Structural changes were observed for the chromosomes of the first homoeologous group (1Rv, 1A, 1D, 1B), as well as for 2B, 5D, 6B, and 7B. The chromosomes 1Rv and 6B often demonstrated aberrations. The types of aberrations were centromeric break, deletions of various sizes, and a changed repeat pSc119.2 localization pattern.

THE WHEAT INTROGRESSIVE FORM EVALUATION BY GRAIN BIOCHEMICAL AND TECHNOLOGICAL PROPERTIES

To create stress-resistant, productive and quality wheat varieties, the genetic diversity of wild and cultured relatives is often used – various species belonging to the genera Triticum and Aegilops. Previously, with Triticum militinae, T. timopheevii, T. kiharae, Aegilops cylindrical and Ae. triaristata samples participation, introgressive winter common wheat forms were created and selected for stability and yield. The purpose of this work was to evaluate the biochemical composition and technological grains properties of these forms. Analysis of gluten content in flour by the ISO method revealed a variability level from 28.5 % for the form Erythrospermum 350 × T. militinae to up to 39.6 % for the Zhetysu × T. militinae genotype. In this case, the 1st groups gluten quality (class “strong”) was found only for the genotypes Erythrospermum 350 × T. militinae (Bezostaya 1 × T. militinae) × T. militinae. According to the physical properties of flour and dough, the introgressive forms vary in the test dilution from 80 to 170 FU at the level of “filler” and “weak” bread wheat with the best value for both liquefaction and valorimetric evaluation for the genotypes Bezostaya 1 × Ae. triaristata and Erythrospermum 350 × T. militinae (80 liquefaction units 49 FU and 80–45 FU, respectively). Bread making evaluation for the introgressive forms was comparable with winter wheat varieties including the Almaly standards (720–760 ml) and Karakhan (800 ml), at the bread quality and the baking evaluation. As for hardness, wild relatives and introgressive forms were characterized mainly as medium and hard (52–93 SKCS units). Thus, the introgressive forms studied were mainly related to the “valuable” and “filler” classes according to the technological bakery type evaluation, to the “weak” class according to the flour strength and bread volume, and to the “strong” class at the glutenin HMW composition forecast and the translocation of 1B/1R.

Insight into cellular proteome of Lolium multiflorum/Festuca arundinacea introgression forms to decipher crucial mechanisms of cold acclimation in forage grasses

Frost tolerance is the main component of winter-hardiness. To express this trait, plants sense low temperature, and respond by activating the process of cold acclimation. The molecular mechanisms of this acclimation have not been fully understood in the agronomically important group of forage grasses, including Lolium-Festuca species. Herein, the introgression forms of L. multiflorum/F. arundinacea distinct with respect to their frost tolerance, were used as models for the comprehensive, proteomic and physiological, research to recognize the crucial components of cold acclimation in forage grasses. The obtained results stressed the importance of photosynthetic performance under acclimation to low temperature. The stable level of photochemical processes after three weeks of cold acclimation in the introgression form with a higher level of frost tolerance, combined simultaneously with only slightly (but not significantly) decreased level of CO2 assimilation after that period, despite significantly lower stomatal conductance, indicated the capacity for that form to acclimate its photosynthesis to low temperature. This phenomenon was driven by the Calvin cycle efficiency, associated with revealed here accumulation profiles and activities of chloroplastic aldolase. The capacity to acclimate the photosynthetic machinery to cold could be one of the most crucial components of forage grass metabolism to improve frost tolerance.

MINERAL COMPOSITION OF WILD RELATIVES AND INTROGRESSIVE FORMS IN WHEAT SELECTION

The study of seed mineral composition of wheat and its wild relatives revealed higher content of all elements in Aegilops ovata and Ae. triuncialis, as well as an overall increased background in relatives compared to modern varieties of Triticum aestivum (standards). By content of macro- and microelements, synthetic forms of wheat occupy an intermediate position between wild relatives and modern varieties. Transitional forms with the level of mineral composition typical of wild forms (Zhetysu×T. militinae; Zhetysu×T. kiharae; Bezostaya 1×Ae. cylindrica) have been identified. All genotypes have been differentiated into 3 clusters. The first consists predominantly of introgressive forms, Ae. triaristata and the Komsomolskaya 1 variety, which has wild forms in its origin. The second cluster includes mainly varieties (parental forms), T. timopheevii and the introgressive form (Steklovidnaya 24×T. militinae). The third cluster consists largely of T. militinae, T. kiharae, Ae. cylindrica species and introgressive forms originated from them: Zhetysu×T. militinae and Bezostaya 1× Ae. cylindrica. Such division allows us to classify genotypes according to the level of metabolism: wild relatives (3rd cluster), varieties (2nd cluster) and an intermediate group – introgressive forms (1st cluster). In general, inclusion of cultural forms (backcrossing with varieties) to crosses with introgressive forms is usually accompanied by a decrease in the total metabolic level, but it varies in cultivars and wild species characterized by polymorphism. Sources of high content of elements have been revealed: wild relatives and introgressive forms, some of which are donors. According to the results of topcross breeding with testers – commercial common wheat varieties Steklovidnaya 24, Almali, Zhetysu – inheritance of this trait by progenies in F 2 –F 3 generations has been revealed in two constant lines: (Bezostaya 1×Ae. cylindrica)×T. kiharae and Zhetysu×T. kiharae.