Marker-assisted Selection Method Research Articles

Localization of Genetic Factors that Determine the Economically-Useful Traits of the PEAR (<i>Pyrus</i>) and Methods of Marker-Assisted Selection

DNA markers are an alternative method for accelerated identification of interested genes and loci at the early stages of ontogenesis, and, consequently, DNA markers are able to intensify the breeding process. This article represents overview of research on the localization of economically useful traits in the pear genome and the development and use of marker-assisted selection (MAS) techniques. At the moment, several traits have been localized in the pear genome, i.e.: resistance to scab European (V. pirina Aderh) and Asian (V. nashicola), black spot (Alternaria alternata (Fr.) Keissler), brown spot (Stemphylium vesicarium), fire blight (Erwinia amylovora), pear psylla (Cacopsylla pyri), pear sawfly (Caliroa cerasi), pear blister mite (Eriophyes pyri), self-incompatibility, dwarf trait. Major genes and loci of quantitative traits (QTLs) of fruits characteristics have also been identified, namely: skin color and rustiness of the fruit, size and weight of the fruit, taste, level of ethylene production, harvest time etc. It should be noted that currently Russian research is limited to the validation and use of MAS methods developed abroad. According to the experience of Japanese scientists, the use of MAS for several key traits has made it possible to triple the efficiency of the breeding process. Despite the currently limited list of MBC methods for pears, the high speed of genomic technologies development promises rapid development of new MAS methods in the future. In combination with new breeding technologies (New Breeding Techniques) based on accelerated flowering, the use of MAS for pears is a promising direction of breeding.

Evaluation of effectiveness resistance genes in wheat genotypes using marker-assisted selection for stripe rust resistance breeding”

Stripe rust, induced by Puccinia striiformis f. sp. tritici, is the most harmful and prevalent disease in temperate regions worldwide, affecting wheat production areas globally. An effective strategy for controlling the disease involves enhancing genetic resistance against stripe rust, achieved through Egyptian breeding efforts not previously conducted on wheat genotypes. The resistance level to stripe rust in thirty-eight wheat genotypes was assessed using marker-assisted selection methods. The investigation suggests that wheat breeding programs can utilize slow-rusting Yr genes, which are effective resistance genes, to develop novel genotypes with stripe rust resistance through marker-assisted breeding. Based on the four disease responses of the wheat genotypes under investigation, the results categorized the genotypes into three groups. The first group included resistant genotypes, the second group exhibited a slow-rusting character with the lowest disease symptom rates, and the last group displayed the highest disease characteristics rates throughout the three seasons, comprising fast-rusting genotypes. The rust-resistant genes identified were Yr5, Yr9, Yr10, Yr15, Yr17, Yr18, Yr26, Yr29, Yr30, and Yr36. Genes Yr26, Yr30, and Yr36 were present in all genotypes. Genotypes Misr3, Misr4, Giza168, Giza167, Giza170, Giza171, Gemmeiza9, and Gemmeiza10 carried the Yr9 gene. Only one genotype, Sids13, was found to have the Yr17 gene. Genes Yr18 and Yr29 were identified in Sids14, Giza168, Giza170, Gemmeiza9, and Gemmeiza10. However, none of the wheat genotypes showed the presence of Yr5, Yr10, or Yr15. Several backcrossing generations were conducted to introduce the Yr5 and Yr10 genes into susceptible genotypes (Misr1, Misr2, and Gemmeiza11). These genotypes are cultivated globally and are known for producing high-quality flour, making them of great importance to farmers. The study demonstrates significant potential for enhancing wheat genotypes for stripe rust resistance and increased production.

Development and validation of allele-specific PCR-based SNP typing in a gene on chromosome D03 conferring resistance to Fusarium wilt race 4 in Upland cotton (Gossypium hirsutum).

Upland cotton (Gossypium hirsutum) is the most important fiber crop for the global textile industry. Fusarium oxysporum f. sp. vasinfectum (FOV) is one of the most destructive soil-borne fungal pathogens in cotton. Among eight pathogenic races and other strains, FOV race 4 (FOV4) is the most virulent race in US cotton production. A single nucleotide polymorphism (SNP) in a glutamate receptor-like gene (GhGLR4.8) on chromosome D03 was previously identified and validated to confer resistance to FOV race 7, and targeted genome sequencing demonstrated that it was also associated with resistance to FOV4. The objective of this study was to develop an easy and convenient PCR-based marker assay. To target the resistance SNP, a forward primer for the SNP with a mismatch in the 3rd position was designed for both the resistance (R) and susceptibility (S) alleles, respectively, with addition of 20-mer T7 promoter primer to the 5' end of the forward primer for the R allele. The two forward primers, in combination with each of five common reverse primers, were targeted to amplify amplicons of 50-260bp in size with R and S alleles differing in 20bp. Results showed that each of three common reverse primers in combination with the two forward primers produced polymorphic markers between R and S plants that were consistent with the targeted genome sequencing results. The polymorphism was distinctly resolved using both polyacrylamide and agarose gel electrophoreses. In addition, a sequence comparative analysis between the resistance gene and homologous sequences in sequenced tetraploid and diploid A and D genome species showed that none of the species possessed the resistance gene allele, suggesting its recent origin from a natural point mutation. The allele-specific PCR-based SNP typing method based on a three-primer combination provides a fast and convenient marker-assisted selection method to search and select for FOV4-resistant Upland cotton.

Single- and multi-trait genomic prediction and genome-wide association analysis of grain yield and micronutrient-related traits in ICARDA wheat under drought environment.

Globally, over 2 billion people suffer from malnutrition due to inadequate intake of micronutrients. Genomic-assisted breeding is identified as a valuable method to facilitate developing new improved plant varieties targeting grain yield and micronutrient-related traits. In this study, a genome-wide association study (GWAS) and single- and multi-trait-based genomic prediction (GP) analysis was conducted using a set of 252 elite wheat genotypes from the International Center for Agricultural Research in Dry Areas (ICARDA). The objective was to identify linked SNP markers, putative candidate genes and to evaluate the genomic estimated breeding values (GEBVs) of grain yield and micronutrient-related traits.. For this purpose, a field trial was conducted at a drought-prone station, Merchouch, Morocco for 2 consecutive years (2018 and 2019) followed by GWAS and genomic prediction analysis with 10,173 quality SNP markers. The studied genotypes exhibited a significant genotypic variation in grain yield and micronutrient-related traits. The GWAS analysis identified highly significantly associated markers and linked putative genes on chromosomes 1B and 2B for zinc (Zn) and iron (Fe) contents, respectively. The genomic predictive ability of selenium (Se) and Fe traits with the multi-trait-based GP GBLUP model was 0.161 and 0.259 improving by 6.62 and 4.44%, respectively, compared to the corresponding single-trait-based models. The identified significantly linked SNP markers, associated putative genes, and developed GP models could potentially facilitate breeding programs targeting to improve the overall genetic gain of wheat breeding for grain yield and biofortification of micronutrients via marker-assisted (MAS) and genomic selection (GS) methods.

Genome-Wide Association Mapping of Processing Quality Traits in Common Wheat (Triticum aestivum L.).

Processing quality is an important economic wheat trait. The marker-assisted selection (MAS) method plays a vital role in accelerating genetic improvement of processing quality. In the present study, processing quality in a panel of 165 cultivars grown in four environments was evaluated by mixograph. An association mapping analysis using 90 K and 660 K single nucleotide polymorphism (SNP) arrays identified 24 loci in chromosomes 1A, 1B (4), 1D, 2A, 2B (2), 3A, 3B, 3D (2), 4A (3), 4B, 5D (2), 6A, 7B (2) and 7D (2), explaining 10.2-42.5% of the phenotypic variances. Totally, 15 loci were stably detected in two or more environments. Nine loci coincided with known genes or QTL, whereas the other fifteen were novel loci. Seven candidate genes encoded 3-ketoacyl-CoA synthase, lipoxygenase, pyridoxal phosphate-dependent decarboxylase, sucrose synthase 3 and a plant lipid transfer protein/Par allergen. SNPs significantly associated with processing quality and accessions with more favorable alleles can be used for marker-assisted selection.

Analysis of nucleotide sequences of the <i>GT47</i> glycosyltransferase gene in rye cultivars differing in the content of water-soluble pentosans in grain

Rye (Secale cereale L.) is the most important crop in Russia, its grain quality depends on the content of water-soluble pentosans. The grain of rye cultivars with high content of water-soluble pentosans has good baking properties, but low fodder qualities. Methods of marker-assisted selection for this trait in rye remain undeveloped. For Triticeae, the content of pentosans in grain may be associated with the GT47 glycosyltransferase genes, but the genes of this family have not been identified in rye. The aim of this study was amplification, sequencing, and search for single nucleotide substitutions or other mutations in the GT47 gene in various rye cultivars differing in the content of water-soluble pentosans in their grain and the viscosity of their aqueous extract. DNA from rye leaves was isolated by the standard CTAB method. Based on the nucleotide sequences of the bread wheat and barley GT47 genes, universal primers were selected, then a fragment of the open reading frames of the studied gene was amplified, and the nucleotide sequences were determined by automatic capillary sequencing. The population cultivars of rye, ‘Chulpan 7’ and ‘Podarok’, and F1 hybrids ‘KVS Aviator’, ‘KVS Magnifico’ and ‘KVS Eterno’ were analyzed. The highest content of pentosans and the highest kinematic viscosity of the aqueous extract were found in cv. ‘Chulpan 7’. The lowest values of these indicators were shown by the hybrid cv. ‘KVS Aviator’. The analysis of the nucleotide sequences of the GT47 gene revealed the presence of single-nucleotide substitutions in seven loci, in which the studied rye cultivars differed. Of these, the high-pentosan cv. ‘Chulpan 7’ and the low-pentosan cv, ‘KVS Aviator’ differed in three nucleotide substitutions: 159 (G/A), 204 (C/T), and 327 (G/A). It is suggested that these SNPs can be used for genotyping rye cultivars for the content of water-soluble pentosans in grain.

Five Regions of the Pea Genome Co-Control Partial Resistance to D. pinodes, Tolerance to Frost, and Some Architectural or Phenological Traits.

Evidence for reciprocal links between plant responses to biotic or abiotic stresses and architectural and developmental traits has been raised using approaches based on epidemiology, physiology, or genetics. Winter pea has been selected for years for many agronomic traits contributing to yield, taking into account architectural or phenological traits such as height or flowering date. It remains nevertheless particularly susceptible to biotic and abiotic stresses, among which Didymella pinodes and frost are leading examples. The purpose of this study was to identify and resize QTL localizations that control partial resistance to D. pinodes, tolerance to frost, and architectural or phenological traits on pea dense genetic maps, considering how QTL colocalizations may impact future winter pea breeding. QTL analysis revealed five metaQTLs distributed over three linkage groups contributing to both D. pinodes disease severity and frost tolerance. At these loci, the haplotypes of alleles increasing both partial resistance to D. pinodes and frost tolerance also delayed the flowering date, increased the number of branches, and/or decreased the stipule length. These results question both the underlying mechanisms of the joint control of biotic stress resistance, abiotic stress tolerance, and plant architecture and phenology and the methods of marker-assisted selection optimizing stress control and productivity in winter pea breeding.

Marker-Assisted Selection of Male-Sterile and Maintainer Line in Chili Improvement by Backcross Breeding

Cytoplasmic genic male sterility (CGMS) is a male sterility system that uses the maternal line for hybrid production, ensuring no obscurity of F1 seed purity and reducing the cost of hybrid seed production. Identification of the male sterility gene is important for plant improvement and classification when using the molecular marker-assisted selection (MAS) method. This study aimed to produce a new maternal line (A-line) and its maintainer line (B-line) by transferring a male-sterile line (A-line) and its maintainer line (B-line) gene from another variety to restorer lines (C-line) to achieve future hybrid seed production. In the process, the CGMS line (A-line) and B-line transferred to C1 and C3 lines, which finally resulted in new A-line (BC2F2A1 × C1, BC2F2A1 × C3), and B-line (BC1F2B1 × C1, BC1F2B1 × C3), and then used the MAS method for detecting genes and pollen viability test in the newly improved lines. The results indicated that the 3336-last2-SCAR (1639 bp) and 4162-SCAR (1046 bp) DNA markers classified the Rf locus, and the CMS-SCAR130/140 marker confirmed the S or N cytoplasm. The BC2F2A1 × C1 and BC2F2A1 × C3 lines represented both male-fertile (SRf_) and male-sterile (Srfrf) progenies in a Mendelian ratio of 3:1. Moreover, stained pollen grains with 1% acetocarmine confirmed abnormal pollen in male-sterile plants. The molecular markers that detect maintainer lines (Nrfrf) are BC1F2B1 × C1-14, BC1F2B1 × C3-10, and BC1F2B1 × C3-11. The 3336-last2-SCAR (1639 bp) and CMS-SCAR130/140 markers successfully identified the male-sterile line (Srfrf) and maintainer line (Nrfrf), and 4162-SCAR (1046 bp) detected the presence of the RfRf or Rfrf genotype in chilies at the seedling stage. The use of these markers was highly accurate and confirmed the results at the early generation stage of a conventional breeding program. It can be concluded that the CGMS and maintainer gene in chilies were successfully transferred during early generation using the backcross method.

Mechanistic Understanding of Leakage and Consequences and Recent Technological Advances in Improving Nitrogen Use Efficiency in Cereals

Although nitrogen (N) is the most limiting nutrient for agricultural production, its overuse is associated with environmental pollution, increased concentration of greenhouse gases, and several human and animal health implications. These implications are greatly affected by biochemical transformations and losses of N such as volatilization, leaching, runoff, and denitrification. Half of the globally produced N fertilizers are used to grow three major cereals—rice, wheat, and maize—and their current level of N recovery is approximately 30–50%. The continuously increasing application of N fertilizers, despite lower recovery of cereals, can further intensify the environmental and health implications of leftover N. To address these implications, the improvement in N use efficiency (NUE) by adopting efficient agronomic practices and modern breeding and biotechnological tools for developing N efficient cultivars requires immediate attention. Conventional and marker-assisted selection methods can be used to map quantitative trait loci, and their introgression in elite germplasm leads to the creation of cultivars with better NUE. Moreover, gene-editing technology gives the opportunity to develop high-yielding cultivars with improved N utilization capacity. The most reliable and cheap methods include agronomic practices such as site-specific N management, enhanced use efficiency fertilizers, resource conservation practices, precision farming, and nano-fertilizers that can help farmers to reduce the environmental losses of N from the soil–plant system, thus improving NUE. Our review illuminates insights into recent advances in local and scientific soil and crop management technologies, along with conventional and modern breeding technologies on how to increase NUE that can help reduce linked N pollution and health implications.

Review on trends of Selection superior Dairy cattle through marker assisted selection methods

Marker-Assisted Selection is selection that used for indirect selection of superior breeding animals that depend on identifying association between genetic marker and linked quantitative traits loci. Since the association between marker and quantitative traits loci depends on distance between marker and target traits. As soon as markers linked to quantitative traits loci have been identified, they can be used in selection programme of dairy cattle that is beneficial when the traits are difficult and expensive to measure and low heritability and recessive traits in dairy cattle. Therefore, Marker-Assisted Selection facilitate the exploitation of existing genetic diversity in breeding populations and can be used to improve desirable traits in dairy cattle. Indeed, currently Marker-Assisted Selection is the most widely used application of marker systems in selection of dairy breeding. Quantitative traits loci affecting milk yield has been identified on 20 of the 29 bovine chromosomes. quantitative traits loci for milk yield on chromosome 1, 3, 9 and 20 are with evidence of quantitative traits loci at lower reported frequency on other chromosomes (5, 7, 10, 12, 14 17, 18, 21, 23, 27 and 29). However, the main limitation of marker-assisted selection is increased cost involved in sample collection for genotyping and complete genotype information. Hence, this paper was aimed to review trends on selection of dairy cattle based on marker assisted selection approach.

Identification of carriers of Puccinia striiformis resistance genes in the population of recombinant inbred wheat lines

Stripe rust (yellow rust) caused by Puccinia striiformis f. sp. tritici, one of the most dangerous diseases of wheat. Marker assisted selection methods make it possible to accelerate the selection of resistance gene donors to improve breeding material through their introduction into hybridization programs. The goal of this study was to determine the presence/absence of yellow rust resistance genes in wheat recombinant inbred lines Almaly/Avocet (S) and to evaluate their response to Pst. Evaluation of seedling resistance to Pst allowed us to select 2 lines simultaneously resistant to races 111Е231 and 7E63. Race 7E63 was avirulent to most samples, and 111Е231 was highly virulent. All the studied lines demonstrated a resistant and moderately resistant reaction to the causative agent of yellow rust at the adult plant stage (R-MR). Molecular screening revealed the presence of a marker allele associated with the Yr18/Lr34 gene complex in 5 RIL. The frequency of resistant genotypes inheriting the Yr18 gene was 22.7%. The results can be used in MAS wheat breeding programs to increase resistance to yellow rust of wheat.

The Development of Two High-Yield and High-Quality Functional Rice Cultivars Using Marker-Assisted Selection and Conventional Breeding Methods.

Rice (Oryza sativa L.) is an important crop worldwide. Functional rice has exhibited health benefits. The aim of this study was to use marker-assisted selection (MAS) to introgress two genes, GE (giant embryo) and OsALDH7 (aldehyde dehydrogenase, golden-like endosperm) into colored rice and obtain high yield functional rice. CNY103108 and CNY103107 are two rice lines with golden-like endosperms and giant embryos. They were used as the donor parents. CNY922401, an elite purple waxy rice line, and TNGSW26, an indica red waxy rice cultivar were used as the recurrent parents. Foreground selection of the progenies was completed using functional markers for GE and OsALDH7, and background selection was completed using molecular markers to recover the background of the recurrent parents. MAS results showed a purple functional rice population (PFR) (CNY922401/CNY103108), with the recovery rate of the recurrent parental genome as 91.3%, and a red functional rice population (RFR) (TNGSW26/CNY103107) with the recovery as 89.8%. After five-season yield trials and several antioxidant activities analyses, PFR32 and RFR13 lines, which have similar yields and antioxidant activities, were selected as the recurrent parents with a golden-like endosperm and a giant embryo. For a biofortification purpose, they can become valuable products and be adapted to the current agricultural community.

Genomic regions controlling yield-related traits in spring wheat: a mini review and a case study for rainfed environments in Australia and China.

A genome-wide association study (GWAS) was performed in six environments to identify major or consistent alleles responsible for wheat yield traits in Australia and North China where rainfed farming system is adopted. A panel of 228 spring wheat varieties were genotyped by double digest restriction-site associated DNA genotyping-by-sequencing. A total of 223 significant marker-trait association (MTAs) and 46 candidate genes for large- or consistent-effect MTAs were identified. The results were compared with previous studies based on a mini-review of 23 GWAS analyses on wheat yield. A phenomenon seldom reported in previous studies was that MTAs responsible for the trait tended to cluster together at certain chromosome segments, and many candidate genes were in the form of gene clusters. Although linkage disequilibrium (LD) might contribute to the co-segregation of the regions, it also suggested that marker-assisted selection (MAS) or transgenic method targeting a single gene might not be as effective as MAS targeting a larger genomic region where all the genes or gene clusters underlying play important roles.

Association of single nucleotide polymorphisms in the CAPN, CAST, LEP, GH, and IGF-1 genes with growth parameters and ultrasound characteristics of the Longissimus dorsi muscle in Colombian hair sheep.

Recognition of the genes that influence livestock production characteristics has allowed researchers to identify single nucleotide polymorphisms (SNPs) associated with phenotypic traits that contribute to higher productivity. The objective of this research was to associate SNPs in the genes calpain (CAPN), calpastatin (CAST), leptin (LEP), growth hormone (GH), and insulin-like growth factor 1 (IGF-1) with the growth characteristics birth weight (BW), weaning weight adjusted at 120days (WW), daily pre-weaning gain (PRADG), adjusted weight at 210days (AW210), and daily post-weaning gain (POADG), and the measures of the Longissimus dorsi muscle based on ultrasound, namely loin eye area (LEA), loin depth (LD), and back fat thickness (BFT), in Colombian hair sheep (OPC). The association between phenotypic and genotypic characteristics was made using the PLINK v.1.9 program using linear regression analysis. There was a statistically significant association (p < 0.05) between the CAST polymorphism (M/N) and BW, a tendency (p = 0.07) for an association between the T → C SNP of the CAPN gene and AW210, and a trend (p = 0.07) for an association between the A → G SNP of the IGF-1 locus and POADG. The LEA and BFT characteristics were not associated with a SNP, while PL was significantly affected by SNPs in the GH and IGF-1 genes. In conclusion, all the genes evaluated were polymorphic, the CAST gene significantly influenced BW, and the GH and IGF-1 genes were associated with LD characteristics. These results could be used to identify individuals with favorable genotypes to implement a marker-assisted selection method.

Screening of blast resistance genes in rice breeding samples

Rice is one of the most widespread and cultivated crops in the world. It is necessary to increase the yield of crops or expand their sown areas to resolve a food security problem in Russia. Current impossibility of expanding rice cultivated areas in the Rostov region and the need to maintain and increase its yield require developing new disease-resistant varieties. Rice genotypes with multiple blast resistance genes avoid significant yield losses. Since pyramiding and selection of resistance genes in the same genotype through traditional selection methods are complicated, it is urgent to search for homozygous samples using marker-assisted selection methods. This study was aimed to identify Pi-1, Pi-2, Pi-33 and Pi-ta blast resistance genes in breeding rice samples by MAS-methods. The study used CTAB-method for DNA-isolation, PCR, electrophoresis on agarose and polyacrylamide gels. The resulting gels were stained in a solution of ethidium bromide and photographed in ultraviolet light. To control the presence of blast resistance genes the following parental cultivars were used: C104LAC for the Pi-1 and Pi-33 genes, C101-A-51 for the Pi-2 gene, IR36 for the Pi-ta gene; Novator and Boyarin as controls of non-functional alleles of all studied genes. The 446 selection samples of the seventh generation were analyzed. As a result of the research, 127 rice samples that combine 2 or 3 different blast resistance genes were identified. The Pi-2 and Pi-33 genes combination was identified in 43 samples (1128/1, 1149/3, 1171/2, 1177/3, 1177/4, 1186/4, et al.). Samples with three resistance genes are the most interesting for selection and further breeding. For developing new blast-resistant varieties, we recommend using rice samples with the following combinations of resistance genes Pi-1+Pi-2+Pi-33 (1197/1, 1226/2, 1271/1, 1272/2), Pi-1+Pi-2+Pi-ta (1197/4, 1304/2, 1304/3, 1482/3, 1482/4, 1486/1) and Pi-2+Pi-33+Pi-ta (1064/1, 1064/3, 1281/2, 1281/3, 1281/4, 1282/2, 1283/1, 1283/2, 1284/3).

Identification of Saltol QTL in the breeding rice samples

One of the main problems in most of the world rice-growing regions is soil salinity. Rice is considered a saline sensitive crop, especially at the early stages of development and in the period of maturity. In the Rostov region, rice is grown in the south-eastern parts, where there are currently difficulties with the operation of the existing reclamation facilities. The problem of saline soils for this region is especially urgent, since a significant part of the arable lands has alkali complexes. In order to return the saline lands into exploitation, it is necessary to develop salt tolerant varieties, which, under crop rotation and maintenance, can contribute to soil desalinization. Due to the difficulty of determining salt tolerance only by estimating the phenotype, it is necessary to use molecular markers associated with this trait. Thus, the purpose of the current work was to identify one of the main Saltol QTL in breeding rice samples of the eighth generation (F8) obtained from hybridizing the donor variety NSYC Rc106 with Russian varieties. For that purpose, there have been used such marker-assisted selection methods as DNA isolation, polymerase chain reaction (PCR), electrophoresis on 2% agarose gels, gels’ coloring in ethidium bromide solution, photography in ultraviolet light and evaluation of the obtained electrophoregrams. As a result of the study of 398 breeding rice samples, there have been identified 67 samples with the functional allele of Saltol QTL (6865/3, 6874/2, Don 7343/4, Don 7343/5, Don 7343/6, Don 7343/7, Don 7343/8, Don 7343/9, Don 7343/10, Don 7337/1, Don 7337/3, Don 7337/4, Don 7337/5, Don 7337/6, Don 7337/7, Don 7337/8, etc.). There have been recommended to use these samples in the further breeding process in order to develop new salinity resistant rice varieties.

ASSESSMENT AND APPLICATION OF MOLECULAR MARKERS IN BREEDING FOR THE RESISTANCE OF TOMATO (SOLANUM LYCOPERSICUM L.) TO LATE BLIGHT (PHYTOPHTHORA INFESTANS)

In order to use marker-assisted selection (MAS) methods in the development of hybrids and tomato varieties resistant to late blight, the efficiency of molecular markers to the alleles resistant to Phytophthora infestans known in the literature was assessed. High efficiency in the identification of homozygous and heterozygous forms using CAPS dTG63 (Hinf1) and SCAR NCLB-9-6678 markers to Ph2 and Ph3 alleles was established respectively. DNA extraction techniques, reaction mixture compositions, as well as amplification and visualization result modes were adapted. The&#x0D; presence of the Ph3 allele in F1-standard Adapt and Alamina hybrids, and F1 Azart, Agenchik, Dzivosny, and Black Brilliant hybrids included in the Register of Varieties of the Republic of Belarus, as well as in the breeding lines of the collections possessed by the Institute of Genetics and Cytology, NAS of Belarus, and the Belarusian State Agricultural Academy was demonstrated.

Effects of restricting energy during the gilt development period on growth and reproduction of lines differing in lean growth rate: responses in reproductive performance and longevity.

Longevity and reproductive performance are economically important traits in the swine industry that are largely influenced by nutrition and other environmental factors. Reproductive performance and longevity through 4 parities was assessed in gilts of 2 genetic lines developed on ad libitum access to feed or restricted to 75% of ad libitum intake. A total of 661 gilts were used in a 2 × 2 factorial with half of the gilts allocated to an ad libitum diet (AL; n = 330), while the other half were energy restricted by 25% (R; n = 331) from 123 to 235 d of age. All gilts were sired by an industry maternal line. Dams of the gilts were from either a Large White (W) by Landrace (L) industry maternal line or Nebraska Selection Line 45X, producing gilts designated as W × L (n = 355) and L45X (n = 306), respectively. Daily estrus detection began at 140 d of age to obtain age at puberty (AP). Gilts (n = 510) were mated on their second or later estrus, beginning at 240 d of age. Sow weight and backfat were recorded at 110 d of gestation and weaning of each parity. Number of live-born, stillborn, and mummified pigs per litter and piglet birth and weaning weights were recorded through 4 parities. More L45X than W × L and more AL than R gilts reached puberty by 230 d of age (P < 0.01). Dietary treatment did not affect probability to produce parities 1 to 4 or any litter trait analyzed. The L45X females tended to be more likely to produce parities 1 (P < 0.08) and 3 (P < 0.06), while W × L had heavier litters at birth (P < 0.01) and weaning (P = 0.01). Treatment by parity interactions (P < 0.01) existed for weight and backfat prior to farrowing and backfat at weaning, and weight at weaning exhibited a line by treatment by parity interaction (P = 0.04) as R sows had lower weights and backfats in earlier parities, but caught up to AL sows in later parities. A treatment by parity interaction (P < 0.01) was also present for backfat loss from farrowing to weaning as R gilts lost less backfat than AL in parities 1 and 2, but more in parities 3 and 4. No significant differences were detected between lines or treatments for lifetime production traits. The populations of pigs and data presented here provide a framework for a diverse array of further studies. Alternative approaches to restrict energy have been assessed in addition to methods of marker-assisted and genomic selection for improvement of litter size and sow longevity.

Correspondence between SOC1 Genotypes and Time of Endodormancy Break in Peach (Prunus persica L. Batsch) Cultivars

Knowledge of dormancy traits are important in peach breeding. Traditional method selection of seedlings takes a long time because of the juvenile period of plants; therefore, novel application of marker assisted selection methods are needed to accelerate this work. The aims of this study were to test the extent of variability in the PpSOC1 gene among 16 peach cultivars and to establish whether the variability of SOC1 can be used as a functional marker for the timing of endodormancy break based on a 14-year phenology evaluation covering nine consecutive phenology phases, from string stage to ripening. Based on an SSR motif of SOC1, three allele categories were detected: one peach cultivar was heterozygous (203/209), while five of the 15 homozygous cultivars carried a 203 bp allele and the remainder were characterized with 218 bp. There were significant correlations between the PpSOC1 alleles and the various phenology phases, the strongest one being observed at the string stage, marking the end of endodormancy. At this stage, PpSOC1 explained 82.6% of the phenotypic variance; cultivars with the 203 allele reached the string stage 11.7 days earlier than those with 218 bp allele. This finding makes the PpSOC1 screening a valuable method in breeding.

Comprehensive Assessment of Promising Potato Hybrids of Breeding VSC RAS

Using the traditional and marker-assisted selection methods, a comprehensive assessment of promising hybrids from the collection of the All-Russian Scientific Center was carried out. The assessment was conducted in 2018–2019 in the Republic of North Ossetia-Alania. As a result of molecular genetic analysis, hybrids were found with complex resistance to potato nematode, virus Y and X viruses - 2 / V, 5 / V, 6 / V, 17 / V, 40 / V, 43 / V, 46 / V, 54 / V, 124 / V, 9 / VI, 22a / VI, 35 / VI, 130 / VI, 71 / VII and 118 / VIII. Use of these selected forms allows optimal protection of potatoes, limitation of the spread of pathogens and prevention of the emergence of more aggressive pathotypes (races and strains). The hybrids with resistance to potato virus Y (with the presence of R-gene markers - 1/I, 3/I, 10/I, 13/I, 11/II, 15/III, 2/V, 5/V, 6/V, 7/V, 10/V/1140, 17/V, 40/V, 43/V, 46/V, 54/V, 124/V, 9/VI, 22a/VI, 35/VI, 100/VI, 130/VI, 71/VII) are of interest for practical breeding, as well as the hybrids with resistance to Phytophthora infestans such as 15/III, 119/IX and the hybrids 15 / III, 35 / VI, 130 / VI and 71 / VII, which have high marketable yield and weight of tuber.&#x0D; Keywords: potato, interspecific hybrids, marker-assisted breeding, resistance genes