Molecular markers in the genetic analysis of crossability of bread wheat with rye

Bread wheat (Triticum aestivum L.), the varieties of which are widely used for the grain production, is difficultly crossable with related species of Triticeae Dum. This factor limits the chance of introduction of alien genetic material into the wheat gene pool and the possibility of new varieties breeding with good adaptation to adverse environmental factors. The crossability between wheat and related species is controlled by Kr1-Kr4 genes (Crossability with Rye, Hordeum and Aegilops spp.) and the SKr gene (Suppressor of crossability). SKr and Kr1 have the largest influence on the trait. In the case of the recessive alleles, these genes do not function and the quantity of hybrid seeds after pollination with alien species can achieve more than 50 %. SKr is located on 5BS between the GBR0233 and Xgwm234 markers, closely linked with the markers Xcfb341, TGlc2 and gene12. Kr1 was mapped on 5BL, proximally to the Ph1 gene, between the EST-SSR markers Xw5145 and Xw9340. The markers of SKr were used to control the transfer of its recessive allele into other wheat genotypes, which made it possible to obtain highly crossable forms. However, the advantages of using the SKr and Kr1 markers in marker-assisted selection and in the screening of ex situ collections are not sufficiently studied. The published Kr1 sequence for varieties with different crossability offers great prospects, because it will be possible to create allele-specific markers. In this review, the following issues are considered: genetic resources created by wheat and rye hybridization, the geographical distribution of easy-to-cross forms of wheat, genetic control of the wheat and rye compatibility, advances of the use of molecular markers in the mapping of Kr-genes and their transmission control

A system of molecular markers to identify alleles of the Rht-B1 and Rht-D1 genes controlling reduced height in bread wheat

Mutant alleles of the Rht-B1 and Rht-D1 (Reduced height) genes are widely used in bread wheat breeding for the development of intensive-type cultivars. These genes and their f lanking regions have been sequenced and the point mutations leading to the nonsense codons (Rht-B1b, Rht-B1e, Rht-B1p and Rht-D1b alleles) and various insertions (Rht-B1c, Rht-B1h and Rht-B1i-1) associated with a change in plant height have been described. DNA-markers based on the allele-specif ic PCR have been developed to identify single-nucleotide changes. However, the use of such technique imposes stringent PCR conditions, and the resulting data are not always unambiguous. An alternative can be found in the CAPS technology: it detects differences in sequences by digesting PCR products. In the absence of restrictases capable of digesting DNA at the point mutation site, restriction sites can be introduced into the primer sequence (derived CAPS). The aim of this study was to propose a system of CAPS-, dCAPS- and STS-markers for identifying alleles of the reduced height genes frequently used in breeding programs. Three CAPS have been developed to identify the Rht-B1b, Rht-D1b, Rht-B1p alleles, as well as two dCAPS for Rht-B1b, Rht-B1e. STS-markers for the insertioncontaining alleles Rht-B1c, Rht-B1h and Rht-B1i-1 have been selected from publications. The proposed markers were tested during the genotyping of 11 bread wheat accessions from the VIR collection with the abovementioned mutant alleles and the wild-type Rht-B1a and Rht-D1a. The presence of nonsense mutations was also conf irmed by the results of allele-specif ic PCR. This marker system, along with the existing ones, can be used to identify dwarf ing alleles of the Rht-B1 and Rht-D1 genes in bread wheat for genetic screening of accessions from ex situ collections and/or for marker-assisted selection

Comparative analysis of the DNA isolated from thyme leaves using different methods

Background. The base for a molecular analysis is DNA of high quality. For DNA isolation, different kits or classical methods are used. For mass analysis, isolation with kits is a very expensive process. So, the objective of our investigation was to find a cheap method for high-quality DNA isolation from leaves of various thyme cultivars.Materials and methods. Leaves cut from thyme accessions (Thymus mastichina L. cv. ‘Svetliachok’, T. striatus Vahl. cv. ‘Jubileiniy’, T. vulgaris L. cv. ‘Fantasia’, and T. vulgaris cv. ‘Jalos’.) maintained ex situ in the collection of the Nikita Botanical Gardens were used as the material for the analysis. Light microscopy was used to study leaf anatomy and localize essential oil on leaf cross sections. Essential oil was extracted on Ginsberg devices, and phenolic content was measured with The Folin–Ciocâlteu reagent (FCR). Commercial kits (DiamondDNATM, PureLink® Plant Total DNA Purification Kit) and classical methods (CTAB, CTAB with 2% polyvinylpyrrolidone) were used for DNA isolation. DNA quality was evaluated spectrophotometrically, with electrophoresis (horizontal, automated system Agilent 4200 TapeStation) and PCR.Results. The analysis showed that the leaf blade mesophyll of four thyme cultivars had inclusions with essential oil. The content of essential oil and phenolic compounds was measured biochemically. Since the plants were characterized by the presence of secondary metabolites, DNA was isolated by different methods. Spectrophotometry demonstrated that the classical CTAB method and CTAB with 2% PVP provided the best results. Using an automated electrophoresis system, the presence of high-molecularweight DNA (more than 52000 bp) in significant amounts was detected in the samples isolated with DiamondDNATM kit and CTAB + 2% PVP.Conclusion. Among the tested kits and methods, CTAB + 2% PVP provided thyme DNA suitable for PCR and, presumably, for genome library preparation. The low cost of reagents for this technique makes it applicable for future mass analysis of plant material

The rate of weight gain and productivity of chicken broiler cross with various polymorphic types of myostatin gene

The search for single nucleotide polymorphisms (SNP) in the myostatin gene is a promising direction of research as this gene is involved in the development of important biological and productive traits in chicken. Using PCR-RFLP technique, an analysis of allele and genotype frequencies in Cornish chicken breed of G5 line of Smena-8 cross has been conducted. Two pairs of primers allowing PCR product to be obtained in the myostatin gene have been used. Two single nucleotide substitutions on exon 1 of the myostatin gene have been under investigation: G/A in MST2109 and G/С in MST2244. A signifiant predominance of deoxynucleotide G in MST2244 over C and deoxynucleotide A over G in MST2109 has been observed. Differences in productive traits between genotypes in MST2109 were not detected. Analysis of allelic variability by MST2244 locus showed statistically significant differences in live weight at the age of 7 days between CC and G2G2 genotypes (p < 0.01), CG2 and G2G2 (p < 0.05). G2G2 individuals (203.52 g) were significantly heavier than CC (179.5 g) and CG2 (193.95 g) chickens at the age of 7 days. Statistically significant differences between the CC and G2G2 genotypes in live weight at the age of 33 days have been revealed (p < 0.05). Thus, this research has led to a better understanding of allele frequencies in the myostatin gene in line G5 of Cornish breed. The results obtained will allow particular myostatin gene-based genotypes to be taken into account for accelerating the breeding process in the broiler poultry industry

Genome-wide association studies targeting the yield of extraembryonic fluid and production traits in Russian White chickens

Background: The Russian White is a gene pool breed, registered in 1953 after crossing White Leghorns with local populations and, for 50 years, selected for cold tolerance and high egg production (EL). The breed has great potential in meeting demands of local food producers, commercial farmers and biotechnology sector of specific pathogen-free (SPF) eggs, the former valuing the breed for its egg weight (EW), EL, age at first egg (AFE), body weight (BW), and the latter for its yield of extraembryonic fluid (YEF) in 12.5-day embryos, ratio of extraembryonic fluid to egg weight, and embryo mass. Moreover, its cold tolerance has been presumably associated with day-old chick down colour (DOCDC) white rather than yellow, the genetic basis of these traits being however poorly understood. Results: We undertook genome-wide association studies (GWASs) for eight performance traits using single nucleotide polymorphism (SNP) genotyping of 146 birds and an Illumina 60KBeadChip. Several suggestive associations (p <5.16*10(-5)) were found for YEF, AFE, BW and EW. Moreover, on chromosome 2, an association with the white DOCDC was found where there is an linkage disequilibrium block of SNPs including genes that are responsible not for colour, but for immune resistance. Conclusions: The obtained GWAS data can be used to explore the genetics of immunity and carry out selection for increasing YEF for SPF eggs production.Peer reviewe

Features of the electron structure of FeTe compounds

A theoretical and experimental study of the electron structure and nature of the chemical bonds in FeTe compounds in antiferromagnetic (AFM) and paramagnetic phases. It is established that the nature of the chemical bonds is mainly metallic, and the presence of covalent bonds Fe-Te and Te-Te helps to stabilize the structural distortions of the tetragonal phase of FeTe in the low-temperature region. It is found that the bicollinear AFM structure corresponds to the ground state of the FeTe compound and the calculated value of the magnetic moment MFe = -2.4μB is in good agreement with the data from neutron diffraction measurements. At the same time, the Fermi surface (FS) of the low-temperature AFM phase is radically different from the FS of the paramagnetic FeTe. Reconstructing the FS can lead to a sign change of the Hall coefficient observed in FeTe. The calculation results serve as evidence of the fact that the electron structures and magnetic properties of FeTe are well-described by the model of itinerant d-electrons and the density functional theory (DFT-GGA)

A tendency towards leaf rust resistance decrease in common wheat introgression lines with genetic material from Aegilops speltoides Tausch

Leaf rust, caused by the fungus Puccinia triticina Erikss., inflicts serious crop loss of common wheat Triticum aesti­vum L. The species Aegilops speltoides Tausch (2n = 14, SS) is considered a promising issue of genes to protect bread wheat from diseases. The objective of this study was the monitoring of resistance to leaf rust of Ae. speltoides ac­cessions and introgressive lines and cultivars with genetic material of this species to the Western Siberian popula­tion of fungus. The estimation of specimens in the field conditions on natural infectious background showed that the Ae. speltoides accessions were immune to leaf rust, however, а tendency towards increasing susceptibility of the introgressive lines and varieties was detected. The protective effect of the known genes Lr28, Lr36 and Lr35 decreased, but Lr47 remained efficient in West Siberia, as confirmed by the results of testing of the Omsk population of P. triticina for virulence to the mentioned genes. During the study (2003-2017) the resistance has been overcome of lines Od 26/89, 156/90, analogs of cv. Novosibirskaya 67 – ANK-39 (B, C), and L-500 from the “Arsenal” сollection. High resistance to leaf rust was preserved of lines Od (35/1, 35/89, 210/90, 278/89); ANK39 (A, D, E); L-501 and cvs. Chelyaba 75 and Mit. Analysis of DNA markers and phytopathological tests showed that the studied variet­ies and lines lacked the known genes Lr28, Lr36, and Lr47 from Ae. speltoides (except for the lines of cvs. Thatcher and Pavon). On the base of analysis of DNA markers, it was assumed that Chelyaba 75 and seven resistant lines from the Odand ANK-39-series have translocations bearing the LrSp gene. Presumably, the rest of samples possess additional not yet identified genes of Ae. speltoides. The trend of overcoming of resistance to leaf rust of introgres­sive lines and varieties with Ae. speltoides genes should be taken into consideration in common wheat breeding in Western Siberia

Genetic variability in local and imported germplasm chicken populations as revealed by analyzing runs of homozygosity

Simple Summary To maintain the uniqueness of conserved chicken populations of local and imported breeds is of great importance. In this study, we genotyped small populations belonging to 14 breeds and 7 crossbreds using an Illumina Chicken 60K SNP (Single Nucleotide Polymorphisms) BeadChip and looked for appropriate methods to characterize their purity/variability. It was not straightforward to identify crossbred individuals, and the best approach was based on calculating the length and number of homozygous regions, or runs of homozygosity (ROH), in the populations studied. The latter enabled most accurate identification of crossbreds and can be served as an effective tool in testing genome-wide purity of chicken breeds. Abstract Preserving breed uniqueness and purity is vitally important in developing conservation/breeding programs for a germplasm collection of rare and endangered chicken breeds. The present study was aimed at analyzing SNP genetic variability of 21 small local and imported purebred and F1 crossbred populations and identifying crossbreeding events via whole-genome evaluation of runs of homozygosity (ROH). The admixture models more efficiently reflected population structure, pinpointing crossbreeding events in the presence of ancestral populations but not in their absence. Multidimensional scaling and FST-based analyses did not discriminate properly between purebred populations and F1 crossbreds, especially when comparing related breeds. When applying the ROH-based approach, more and longer ROHs were revealed in purebred individuals/populations, suggesting this as an effective implement in genome-wide analysis of germplasm breed purity