Alien Genes Research Articles

Cytological stability of wheat amphidiploids and cultivars in meiosis I

Introgression of genes controlling useful traits into a common wheat gene pool is still a highly actual task. Amphidiploids usually serve as a bridge for transferring alien genes into the wheat genome. One of the conditions of successful use of amphidiploids as sources of alien genes is their cytological stability and fertility. Cytological stability of the genome substitution amphidiploids Aurotica and Auroale was determined through characterization of different meiosis stages by studding cytological preparations. Amphidiploids were characterized by deviations from the bivalent chromosome conjugation, appearance of multivalent chromosome associations, and univalent chromosomes in metaphase I. In the anaphase, bridges were observed. Univalents and chromosome fragments resulted from the bridges breakage caused appearance of micronuclei in tetrads. Conjugation of chromosomes in common wheat cultivars, studied for comparison, was bivalent, with the absolute preference of closed bivalents in metaphase plates. The meiotic index calculated on quantitative characteristics of amphidiploids with micronuclei and polyads was similar for Aurotica and Auroale and varied between 64–69 %. In tetrads of Auroale no triads were found, whereas in Aurotica triads were usual. So, the meiotic index in itself is not an indicator for the meiotic stability of a plant sample. More exhaustive information can be received through structuring of the meiotic index for assessment of components which are used for its calculation. The received results enable to assume that meiotic abnormalities in Aurotica may be caused by disorder of synchrony in meiosis II processes, whereas for Auroale this disorder is not typical. Gametogenesis in amphidiploids sometimes demonstrated appearance of the third generative nucleus in the male gametophyte. Determined meiosis characteristics explain the decline in seed fertility of Aurotica, and in particular Auroale, compared to common wheat cultivars.Manuscript received 13.04.2020

Functional characterization of wheat myo-inositol oxygenase promoter under different abiotic stress conditions in Arabidopsis thaliana.

The production of wheat is severely affected by abiotic stresses such as cold, drought, salinity, and high temperature. Although constitutive promoters are frequently used to regulate the expression of alien genes, these may lead to undesirable side-effects in transgenic plants. Therefore, identification and characterization of an inducible promoter that can express transgene only when exposed to stresses are of great importance in the genetic engineering of crop plants. Previous studies have indicated the abiotic stress-responsive behavior of myo-inositol oxygenase (MIOX) gene in different plants. Here, we isolated the MIOX gene promoter from wheat (TaMIOX). The in-silico analysis revealed the presence of various abiotic stress-responsive cis-elements in the promoter region. The TaMIOX promoter was fused with the UidA reporter gene and transformed into Arabidopsis thaliana. The T3 single-copy homozygous lines were analyzed for GUS activity using histochemical and fluorometric assays. Transcript expression of TaMIOX::UidA was significantly up-regulated by heat (fivefold), cold (sevenfold), and drought (fivefold) stresses as compared to transgenic plants grown without stress-induced conditions. The CaMV35S::UidA plants showed very high GUS activity even in normal conditions. In contrast, the TaMIOX::UidA plants showed prominent GUS activity only in stress treatments (cold, heat, and drought), which suggests the inducible behavior of the TaMIOX promoter. The substrate myo-inositol feeding assay of TaMIOX::UidA plants showed lesser GUS activity as compared to plants treated in abiotic stress conditions. Results support that the TaMIOX promoter could be used as a potential candidate for conditional expression of the transgene in abiotic stress conditions.

Combining genome composition and differential gene expression analyses reveals that SmPGH1 contributes to bacterial wilt resistance in somatic hybrids.

Clarification of the genome composition of the potato + eggplant somatic hybrids cooperated with transcriptome analysis efficiently identified the eggplant gene SmPGH1 that contributes to bacterial wilt resistance. The cultivated potato is susceptible and lacks resistance to bacterial wilt (BW), a soil-borne disease caused by Ralstonia solanacearum. It also has interspecies incompatibility within Solanaceae plants. Previously, we have successfully conducted the protoplast fusion of potato and eggplant and regenerated somatic hybrids that showing resistance to eggplant BW. For efficient use of these novel germplasm and improve BW resistance of cultivated potato, it is essential to dissect the genetic basis of the resistance to BW obtained from eggplant. The strategy of combining genome composition and transcriptome analysis was established to explore the gene that confers BW resistance to the hybrids. Genome composition of the 90 somatic hybrids was studied using genomic in situ hybridization coupled with 44 selected eggplant-specific SSRs (smSSRs). The analysis revealed a diverse set of genome combinations among the hybrids and showed a possibility of integration of alien genes along with the detection of 7 smSSRs linked to BW resistance (BW-linked SSRs) in the hybrids. Transcriptome comparison between the resistant and susceptible gene pools identified a BW resistance associated gene, smPGH1, which was significantly induced by R. solanacearum in the resistant pool. Remarkably, smPGH1 was co-localized with the BW-linked SSR emh01E15 on eggplant chromosome 9, which was further confirmed that smPGH1 was activated by R. solanacearum only in the resistant hybrids. Taken together, the identified gene smPGH1 and BW-linked SSRs have provided novel genetic resources that will aid in potato breeding for BW resistance.

Distant hybridization and introgression of alien genes for improving heterotic potential and resistance to various biotic stresses in vegetable and oilseed brassicas (Brassica Sp.)

Distant hybridization and introgression of alien genes for improving heterotic potential and resistance to various biotic stresses in vegetable and oilseed brassicas (Brassica Sp.)

Screening of pathogenicity-deficient Fusarium oxysporum mutants established by Agrobacterium tumefaciens-mediated transformation

Apple replant disease (ARD) occurs frequently in old orchards and is an important disease that limits apple production in China. Fusarium oxysporum is one of the causal agents of ARD and its pathogenic mechanism is still unclear. To explore the potential pathogenesis-related genes of this pathogen, a T-DNA insertion library of F. oxysporum HS2 was constructed via optimized Agrobacterium tumefaciens-mediated transformation (ATMT). The ATMT system yielded 160–200 transformants/106 conidia, indicating a relatively high conversion efficiency. The genetically stable transformants were tested through five generations of successive subculture on hygromycin-free media, and the alien gene was detected via PCR. A total of 3500 transformants were obtained to produce a T-DNA insertion library of F. oxysporum HS2, and 223 of these mutants were randomly selected for sporulation and pathogenicity tests. Most of the tested mutants presented weakened virulence, and one of them displayed obviously attenuated sporulation and reduced pathogenicity. The T-DNA in six pathogenicity-deficient mutants existed as a single copy, as confirmed by Southern blotting. The T-DNA flanking sequence was obtained rapidly by successive chromosome walking via the high-efficiency thermal asymmetric interlaced polymerase chain reaction (hiTAIL-PCR) method. The T-DNA right flanking sequences of five transformants were identified further, and the obtained sequences were aligned to the genomic sequence, revealing novel loci related to pathogenesis. This study provided a large number of various pathogenesis-related mutants and pathogenesis-related genes, which will be valuable resources for characterizing the molecular mechanisms of pathogenesis-related genes.

Crossing the pond: genetic assignment detects lobster hybridisation

American lobsters (Homarus americanus) imported live into Europe as a seafood commodity have occasionally been released or escaped into the wild, within the range of an allopatric congener, the European lobster (H. gammarus). In addition to disease and competition, introduced lobsters threaten native populations through hybridisation, but morphological discriminants used for species identification are unable to discern hybrids, so molecular methods are required. We tested an array of 79 single nucleotide polymorphisms (SNPs) for their utility to distinguish 1,308 H. gammarus from 38 H. americanus and 30 hybrid offspring from an American female captured in Sweden. These loci provide powerful species assignment in Homarus, enabling the robust identification of hybrid and American individuals among a survey of European stock. Moreover, a subset panel of the 12 most powerful SNPs is sufficient to separate the two pure species, even when tissues have been cooked, and can detect the introduced component of hybrids. We conclude that these SNP loci can unambiguously identify hybrid lobsters that may be undetectable via basic morphology, and offer a valuable tool to investigate the prevalence of cryptic hybridisation in the wild. Such investigations are required to properly evaluate the potential for introgression of alien genes into European lobster populations.

Engineered Durum Wheat Germplasm with Multiple Alien Introgressions: Agronomic and Quality Performance

If genetic gains in wheat yield are to be achieved in today’s breeding, increasing the genetic variability of cultivated genotypes is an essential requisite to meet. To this aim, alien gene transfer through chromosome engineering (CE) is a validated and sound strategy. Attempts to incorporate more than one alien segment into cultivated wheat have been rare, particularly for tetraploid durum wheat. Here, we present the agronomic and quality performance of the first successful CE-mediated multiple introgression into the latter species. By assembling into 7AL, 3BS, and 1AS arms of a single genotype homoeologous segments of Thinopyrum ponticum 7el1L, Aegilops longissima 3SlS, and Triticum aestivum 1DS arms, respectively, we have stacked several valuable alien genes, comprising Lr19+Sr25+Yp (leaf and stem rust resistance and a gene increasing semolina yellowness), Pm13 (powdery mildew resistance), and Gli-D1/Glu-D3 (genes affecting gluten properties), respectively. Advanced progenies of single, double, and triple recombinants were field-tested across three years in a typical durum wheat growing area of central Italy. The results showed that not only all recombinants had normal phenotype and fertility, but also that one of the triple recombinants had the highest yield through all seasons compared with all other recombinants and control cultivars. Moreover, the multiple introgressions enhanced quality traits, including gluten characteristics and semolina yellow index. The presence of effective disease resistance genes confers additional breeding value to the novel and functional CE products, which can greatly contribute to crop security and safety.

Genome-wide impacts of alien chromatin introgression on wheat gene transcriptions

Agronomic characteristics and tolerance to biotic and abiotic stresses in hexaploid wheat can be drastically improved through wheat-alien introgression. However, the transcriptional level interactions of introduced alien genes in the wheat genetic background is rarely investigated. In this study, we report the genome-wide impacts of introgressed chromosomes derived from Ae. longissima on gene transcriptions of the wheat landrace Chinese Spring. RNA-seq analyses demonstrated 5.37% and 4.30% of the genes were significantly differentially expressed (DEGs) in CS-Ae. longissima disomic 3Sl#2(3B) substitution line TA3575 and disomic 6Sl#3 addition line TA7548, respectively when compared to CS. In addition, 561 DEGs, including 413 up-regulated and 148 down-regulated or not transcribed genes, were simultaneously impacted by introgressed chromosomes 3Sl#2 and 6Sl#3, which accounts for 41.25% of the DEGs in TA3575 and 38.79% in TA7548. Seventeen DEGs, annotated as R genes, were shared by both introgression lines carrying chromosomes 3Sl#2 and 6Sl#3, which confer resistance to powdery mildew. This study will benefit the understanding of the wheat gene responses as result of alien gene(s) or chromosome intogression and the plant defense response initiated by powdery mildew resistance genes in chromosomes 3Sl#2 and 6Sl#3.

MATHEMATICAL AND COMPUTER MODELLING REGULATORIKA OF HIERARCHICAL MOLECULAR-GENETIC SYSTEMS

The progress achieved in biology during the last century has led to development of mathematical and computer modelling of functioning regulatory mechanisms (regulatorika) in molecular-genetic processes in living systems. In this work we consider one of the possible methods for mathematical and computer mod- elling of molecular-genetic systems regulatorika. The corresponding equations (in the class of delay functional-differential equations) are developed, using the approaches by B.Goodwin, Bl. Sendov, M. Eigen, B.A. Ratner, and taking into account of tempo- rary relations, presence of multifunctional feedback and cooperative nature of processes in cell's regulatory loops. Results on the regulatorika for uniform molecular-genetic systems, as well as the problem of the origin and development of hierarchical molecular- genetic systems are considered. Results of using the considered method for analyzing cell's molecular-genetic systems in the presence of the alien genes (on the example of hepatic cell infections by hepatitis B virus) are given. 1 Introduction The analysis of main protein-ferments participating in the specific func- tioning of cells in a multicellular organism shows, that each cell contains different complex of protein molecules, though all cells have the same set of chromosomes and, consequently, identical genetic information (1, 2, 3). It happens because in eukaryotic cells there is mech- anism of hierarchical organizations of molecular-genetic system, regulating genes activity: which groups of genes at the moment must be active and which genes should be in the inactive condition. Existence of biochemical properties and processes, inherent all cells of the organism (syntheses of energy proteins, amino acid, to maintain and build membrane, etc) shows that there are universal groups of genes functioning in all cells regardless of specialization. Remaining part of genes consists of groups of general genes (its operation depends on activity conditions in universal groups of genes), containing information on general functions characteristic for many, but not all cells and groups of specific genes (its functioning depends on activity conditions of universal and general genes groups), keeping information on strictly specific functions of concrete cells (4). Under such approach, the whole cell genome of multicellular organism works as evolutionary established hierarchical system of universal, general and specific genes groups (Figure 1). Hierarchical organization of molecular-genetic systems is of the utmost importance in regulatorika of intracellular processes and cellular functions. Their account makes it possible to carry out studying mechanisms of origin, existence and development of living systems when quantitatively analyzing activity patterns of molecular-genetic systems. In this work we develop the mathematical modelling of genes activity (section 2), possible equations of molecular-genetic systems regulatorika (sections 3,4) and certain problems concerning the mathematical and computer modelling of hierarchical molecular-genetic systems (sections

Scale development and utilization of universal PCR-based and high-throughput KASP markers specific for chromosome arms of rye (Secale cereale L.)

BackgroundRye (Secale cereale L., 2n = 2x = 14, RR), a relative of common wheat, is a large gene resource pool for wheat improvement. Accurate and convenient identification of the rye chromatin in wheat background will facilitate the transfer and utilization of elite genes derived from rye in wheat breeding.ResultsIn the present study, five rye cultivars including Imperial, German White, Jingzhouheimai, Baili and Guyuan were sequenced by specific-locus amplified fragment sequencing (SLAF-seq) to develop large-scale rye-specific markers. Based on SLAF-seq and bioinformatics analyses, a total of 404 universal PCR-based and a whole set of Kompetitive allele-specific PCR (KASP) markers specific for the 14 individual rye chromosome arms were developed and validated. Additionally, two KASP markers specific for 1RS and 2RL were successfully applied in the detection of 1RS translocations in a natural population and 2RL chromosome arms in wheat-rye derived progenies that conferred adult resistance to powdery mildew.ConclusionThe 404 PCR-based markers and 14 KASP markers specific for the 14 individual rye chromosome arms developed in this study can enrich the marker densities for gene mapping and accelerate the utilization of rye-derived genes in wheat improvement. Especially, the KASP markers achieved high-throughput and accurate detection of rye chromatin in wheat background, thus can be efficiently used in marker-assisted selection (MAS). Besides, the strategy of rye-specific PCR-based markers converting into KASP markers was high-efficient and low-cost, which will facilitate the tracing of alien genes, and can also be referred for other wheat relatives.

Breeding of bread wheat for leaf rust resistance in Russia

Leaf rust, caused by the fungus Puccinia triticina Erikss., is one of the most common diseases of wheat in Russia. The paper reviews Lr-genes diversity in Russian commercial wheat varieties. Two hundred and sixty-four winter and one hundred and forty-three spring wheat varieties indexed by the State Register of Breeding Achievements in 2005-2018 were studied. It was found that among new varieties, as many as 5% of winter wheat and 30% of spring wheat possess effective seedling resistance. The wide presence of Lr19 and Lr9 genes was detected in the spring wheat. Besides, the high resistance to leaf rust was found in spring wheat varieties with new alien Lr genes (originated from Thinopyrum intermedium (Host) Barkworth & D.R. Dewey and Aegilops speltoides Tausch. Over 40% of winter wheat varieties have different levels of field resistance as well. The molecular screening revealed three varieties with effective adult plant resistance gene Lr37. Other winter wheat varieties include a range of ineffective genes (Lr1, Lr3, Lr10, Lr26, and Lr34), alone or in various combinations.

Characterization of a wheat\u2013tetraploid Thinopyrum elongatum 1E(1D) substitution line K17\u2013841-1 by cytological and phenotypic analysis and developed molecular markers

BackgroundTetraploid Thinopyrum elongatum (2n = 4x = 28) is a promising source of useful genes, including those related to adaptability and resistance to diverse biotic (Fusarium head blight, rust, powdery mildew, and yellow dwarf virus) and abiotic (cold, drought, and salt) stresses. However, gene transfer rates are low for this species and relatively few species-specific molecular markers are available.ResultsThe wheat-tetraploid Th. elongatum line K17–841-1 derived from a cross between a hexaploid Trititrigia and Sichuan wheat cultivars was characterized based on sequential genomic and fluorescence in situ hybridizations and simple sequence repeat markers. We revealed that K17–841-1 is a 1E (1D) chromosomal substitution line that is highly resistant to stripe rust pathogen strains prevalent in China. By comparing the sequences generated during genotyping-by-sequencing (GBS), we obtained 597 specific fragments on the 1E chromosome of tetraploid Th. elongatum. A total of 235 primers were designed and 165 new Th. elongatum-specific markers were developed, with an efficiency of up to 70%. Marker validation analyses indicated that 25 specific markers can discriminate between the tetraploid Th. elongatum chromosomes and the chromosomes of other wheat-related species. An evaluation of the utility of these markers in a F2 breeding population suggested these markers are linked to the stripe rust resistance gene on chromosome 1E. Furthermore, 28 markers are unique to diploid Th. elongatum, tetraploid Th. elongatum, or decaploid Thinopyrum ponticum, which carry the E genome. Finally, 48 and 74 markers revealed polymorphisms between Thinopyrum E-genome- containing species and Thinopyrum bessarabicum (Eb) and Pseudoroegneria libanotica (St), respectively.ConclusionsThis new substitution line provide appropriate bridge–breeding–materials for alien gene introgression to improve wheat stripe rust resistance. The markers developed using GBS technology in this study may be useful for the high-throughput and accurate detection of tetraploid Th. elongatum DNA in diverse materials. They may also be relevant for investigating the genetic differences and phylogenetic relationships among E, Eb, St, and other closely-related genomes and for further characterizing these complex species.

Molecular cytogenetic characterization of wheat\u2013Elymus repens chromosomal translocation lines with resistance to Fusarium head blight and stripe rust

BackgroundFusarium head blight (FHB) caused by the fungus Fusarium graminearum Schwabe and stripe rust caused by Puccinia striiformis f. sp. tritici are devastating diseases that affect wheat production worldwide. The use of disease-resistant genes and cultivars is the most effective means of reducing fungicide applications to combat these diseases. Elymus repens (2n = 6x = 42, StStStStHH) is a potentially useful germplasm of FHB and stripe rust resistance for wheat improvement.ResultsHere, we report the development and characterization of two wheat–E. repens lines derived from the progeny of common wheat–E. repens hybrids. Cytological studies indicated that the mean chromosome configuration of K15–1192-2 and K15–1194-2 at meiosis were 2n = 42 = 0.86 I + 17.46 II (ring) + 3.11 II (rod) and 2n = 42 = 2.45 I + 14.17 II (ring) + 5.50 II (rod) + 0.07 III, respectively. Genomic and fluorescence in situ hybridization karyotyping and simple sequence repeats markers revealed that K15–1192-2 was a wheat–E. repens 3D/?St double terminal chromosomal translocation line. Line K15–1194-2 was identified as harboring a pair of 7DS/?StL Robertsonian translocations and one 3D/?St double terminal translocational chromosome. Further analyses using specific expressed sequence tag-SSR markers confirmed that the wheat–E. repens translocations involved the 3St chromatin in both lines. Furthermore, compared with the wheat parent Chuannong16, K15–1192-2 and K15–1194-2 expressed high levels of resistance to FHB and stripe rust pathogens prevalent in China.ConclusionsThus, this study has determined that the chromosome 3St of E. repens harbors gene(s) highly resistant to FHB and stripe rust, and chromatin of 3St introgressed into wheat chromosomes completely presented the resistance, indicating the feasibility of using these translocation lines as novel material for breeding resistant wheat cultivars and alien gene mining.

Alien genes from bacteria helped plants conquer the land

Alien genes from bacteria helped plants conquer the land

Using CRISPR/Cas9 to produce haploid inducers of carrot through targeted mutations of centromeric histone H3 (CENH3)

The generation of haploids is one of the most powerful means to accelerate the plant breeding process. Based on recent results published for Arabidopsis thaliana, manipulating the centromeres of the chromosomes has been proposed as a novel breeding tool for the production of haploid crop plants. By this way, haploids can be generated through cross-fertilizations after manipulating a single centromere protein, the centromere-specific histone H3 variant CENH3, in one of the parents designated as ‘haploid inducer’. In our carrot research, we are using the CRISPR/Cas9 technique in combination with an Agrobacterium rhizogenes-mediated transformation system to induce mutations in the carrot CENH3 gene. We are investigating two different approaches for CENH3-based uniparental genome elimination called as ‘1-Step’ and ‘2-Step’ strategies. In the ‘1-Step’ approach we are testing regenerated carrot plants carrying non-lethal mutations within the endogenous CENH3 gene for putative haploid inducer effects. The ‘2-Step’ strategy is based on a fully knocked-out carrot CENH3 gene which is rescued by an alien CENH3 gene isolated from a related plant species. Co-transformations of CRISPR/Cas9-based knockout constructs together with a ginseng (Panax ginseng) CENH3 gene were performed by using A. rhizogenes. We show that we could successfully target the carrot CENH3 gene and that the ginseng CENH3 protein is accumulated inside the kinetochore region. We also discuss preliminary results from crosses with putative haploid inducer genotypes developed by the ‘2-step’ approach.

Dissection and cytological mapping of chromosome arm 4VS by the development of wheat-Haynaldia villosa structural aberration library.

A cytological map of Haynaldia villosa chromosome arm 4VS was constructed to facilitate the identification and utilization of beneficial genes on 4VS. Induction of wheat-alien chromosomal structure aberrations not only provides new germplasm for wheat improvement, but also allows assignment of favorable genes to define physical regions. Especially, the translocation or introgression lines carrying alien chromosomal fragments with different sizes are useful for breeding and alien gene mapping. Chromosome arm 4VS of Haynaldia villosa (L.) Schur (syn. Dasypyrum villosum (L.) P. Candargy) confers resistances to eyespot and wheat yellow mosaic virus (WYMV). In this research, we used both irradiation and the pairing homoeologous gene (Ph) mutant to induce chromosomal aberrations or translocations. By using the two approaches, a structural aberration library of chromosome arm 4VS was constructed. In this library, there are 57 homozygous structural aberrations, in which, 39 were induced by the Triticum aestivum cv. Chinese Spring (CS) ph1b mutant (CS ph1b) and 18 were induced by irradiation. The aberrations included four types, i.e., terminal translocation, interstitial translocation, deletion and complex structural aberration. The 4VS cytological map was constructed by amplification in the developed homozygous aberrations using 199 4VS-specific markers, which could be allocated into 39 bins on 4VS. These bins were further assigned to their corresponding physical regions of chromosome arm 4DS based on BLASTn search of the marker sequences against the reference sequence of Aegilops tauschii Cosson. The developed genetic stocks and cytological map provide genetic stocks for wheat breeding as well as alien gene tagging.

Plasticity in Triticeae centromere DNA sequences: a wheat × tall wheatgrass (decaploid) model.

Centromeres mediate chromosome attachment to microtubules and maintain the integrity of chromosomes for proper segregation of the sister chromatids during cell division. Advances in the assembly of Triticeae genome sequences combined with the capacity to recover hybrid species derived from very distantly related species provides potential experimental systems for linking retrotransposon amplification and repositioning of centromeres via non-mendelian inheritance in partial amphiploid breeds. The decaploid tall wheatgrass (Thinopyrum ponticum) is one of the most successfully used perennial species in wheat breeding for generating translocation lines with valuable agronomic traits. We found that wheat centromere retrotransposons CRW and Quinta widely occur within the tall wheatgrass genome. In addition, one of the genome donors to Th. ponticum, Pseudoroegneria stipifolia (StSt), has been shown to have Abigail and a satellite repeat, CentSt. We also found two other centromeric retrotransposons, Abia and CL135 in Th. ponticum by ChIP-seq. Examination of partial amphiploid lines that were generated in the 1970s demonstrated extensive modification in centromere sequences using CentSt, Abigail and Abia as probes. We also detected that St-genome chromosomes were more enriched with Abigail and CentSt, whereas E-genome chromosomes were enriched with CRW and Quinta in tall wheatgrass and its closer relatives. It can be concluded that bursts of transposition of retrotransposons and repositioning of centromeres via non-mendelian segregation are common in partial amphiploids derived from interspecific hybrids. Practically speaking, our study reveals that the existence of homologous centromere functional sequences in both a donor and its receptor can substantially contribute to the successful transfer of alien genes into crop species. OPEN RESEARCH BADGES: This article has earned an Open Data Badge for making publicly available the digitally-shareable data necessary to reproduce the reported results. The data is available at https://www.ncbi.nlm.nih.gov/sra/SRR9089557; https://www.ncbi.nlm.nih.gov/sra/SRR9089558; https://www.ncbi.nlm.nih.gov/sra/SRR9089559; https://www.ncbi.nlm.nih.gov/sra/SRR9089560; https://www.ncbi.nlm.nih.gov/sra/SRR9089561; https://www.ncbi.nlm.nih.gov/sra/SRR9089562; https://www.ncbi.nlm.nih.gov/sra/SRR9089563; https://www.ncbi.nlm.nih.gov/sra/SRR9089564; https://www.ncbi.nlm.nih.gov/nuccore/MK999394; https://www.ncbi.nlm.nih.gov/nuccore/MK999395; https://www.ncbi.nlm.nih.gov/nuccore/MK999396.

Development of wheat—Hordeum chilense Chromosome 2Hch Introgression Lines Potentially Useful for Improving Grain Quality Traits

The chromosome 2Hch of Hordeum chilense. has the potential to improve seed carotenoid content in wheat as it carries a set of endosperm carotenoid-related genes. We have obtained structural changes in chromosome 2Hch in a common wheat (Triticum aestivum L. “Chinese Spring”) background by crossing a wheat double disomic substitution 2Hch(2D) and 7Hch(7D) line with a disomic addition line carrying chromosome 2Cc from Aegilops cylindrica Host.. Seven introgressions of chromosome 2Hch into wheat were characterized by fluorescence in situ hybridization (FISH) and DNA markers. Chromosome-specific simple sequence repeats (SSRs) were used for identifying wheat chromosomes. In addition, we tested 82 conserved orthologous set (COS) markers for homoeologous group 2, of which 65 amplified targets in H. chilense and 26 showed polymorphism between H. chilense and wheat. A total of 24 markers were assigned to chromosome 2Hch with eight allocated to 2HchS and 16 to 2HchL. Among the seven introgressions there was a disomic substitution line 2Hch(2D), a ditelosomic addition line for the 2HchL arm, an isochromosome for the 2HchL arm, a homozygous centromeric 2HchS·2DL translocation, a double monosomic 2HchS·2DL plus 7HchS·D translocation, a homozygous centromeric 7HchS·2HchL translocation and, finally, a 2HchL·7HchL translocation. Wheat—H. chilense macrosyntenic comparisons using COS markers revealed that H. chilense chromosome 2Hch exhibits synteny to wheat homoeologous group 2 chromosomes, and the COS markers assigned to this chromosome will facilitate alien gene introgression into wheat. The genetic stocks developed here include new wheat—H. chilense recombinations which are useful for studying the effect of chromosome 2Hch on grain quality traits.

Chromosome specific microsatellite analysis of common wheat lines resistant to powdery mildew

Aim. Determine the chromosome localization of introgressions containing alien genes for resistance to powdery mildew transferred to the wheat genome from three Aegilops species: Ae. sharonensis, Ae. speltoides, and Ae. umbellulata. Methods. Comparative microsatellite analysis of amplicons’ spectra, derived from PCR with primers to SSR loci localized on seven chromosomes of wheat D subgenome. Results. Spectra of amplification of products with DNA of Aurora cultivar, genome substitution amphidiploids Aurosis, Aurodes and Aurolata, using primers to 44 microsatellite loci localized on seven chromosomes of common wheat D subgenome have been obtained. Absence of genome specificity has been determined for most of the analyzed loci. All the studied introgressive lines have been characterized by allele polymorphism for different number of microsatellite loci from all seven chromosomes of D subgenome. This polymorphism included new components in amplicons spectra, which have been different from components of Aurora and genome substituted amphidiploids. Heterozygous genotypes have been also observed. A part of polymorphic loci has been uninformative because the chromosome of genome substituted amphidiploid had null-allele for such loci. For specification of the information about homeological identity of alien chromatin in resistant lines, genes of morphological traits with known chromosome localization have been used. Conclusions. Screening of resistant to powdery mildew wheat introgressive lines for microsatellite loci does not allow an unambiguous identification of chromosome localization of resistance gene because of high polymorphism of microsatellite loci in the genomes of introgressive lines, and because many loci are non-informative. Assumptions have been made about possible connections of resistance genes with chromosomes of homeological groups 3 and 6 in lines derived from Aurodes; 1, 2, 3, and 6 – in lines derived from Aurolata; and homeological group 2 in lines derived from Aurosis.

Use of introgression winter bread wheat lines to increase the protein content in grain

Introduction. The problem of genetic increase in the protein content is the most important scientific and practical objective in plant breeding. Interspecies hybridization is a tools to expand the genetic diversity of wheat, in particular with respect to the protein content. Several breeding lines with alien polygenic complexes for disease resistance, high 1000-grain weight, protein content and morphological characters were obtained using crosses of original introgressive lines, collection accessions, amphiploids and elite synthetics derived from Ae. tauschii with modern wheat varieties.Aim and objectives of research. To perform comparative breeding evaluation of newly developed introgressive lines; to determine correlations between some agronomic characters and economic features; to select large-seeded, high-protein donor lines with high performance and a set of valuable characters of alien origin.Material and methods. 736 introgressive lines of bread wheat of different generations, saturation degrees and origin were studied. Generally, they were derivatives with different alien characters from distant hybridization and properties from several winter bread wheat varieties (Odesskaya 267, Albatros, Nikoniya, Selianka, Kuyalnik, Panna, Gurt), which were crossed with two original recombinant introgressive lines, one collection accession, two original amphiploids derived from Elymus sibiricus L., and six amphiploids derived from Ae. tauschii. The field experiments were laid out in compliance with the conventional design of the breeding of self-pollinating crops. The endosperm consistency and SDS30 sedimentation index were measured by the methods developed in the Department of Genetic Basics of Breeding of PBGI– NCSCI; the protein content - by the Kjeldahl digestion on a Kjeltec-Auto 1030 analyzer; 1000-grain weight – by the conventional technique; the data were statistically processed by standard methods.Results and discussion. The results of the 2015/16-2017/18 trials distinguished several lines (IL910/16, IL911/16, IL914/16, IL940/16, and IL953/16) with a high relative protein content. They are of interest for transgressive breeding for large grain and increased protein content. In addition, promising breeding lines (E196/09, E2792/14, IL299/16, IL997/16, IL1073/16, IL1100/16, IL1161/16, IL334/17, and IL480/17) combining performance equal to or higher than that of the standard, with alien complexes of disease resistance, high protein content and xeromorphic morphological characters but without negative features of wild species, were singled out.Conclusions. The studied lines may be of interest for further breeding in the South of Ukraine, provided preservation of the alien gene complexes.