Molecular marker analysis of <Emphasis Type="Italic">Cynanchum wilfordii</Emphasis> and <Emphasis Type="Italic">C. auriculatum</Emphasis> using the simple ARMS-PCR method with mismatched primers

SNPs can be used to discriminate allele-specific genotypes based on the 3′-terminal nucleotide of a primer corresponding to a specific SNP site. However, reliable discrimination between alleles in closely related species is not sufficient for molecular genetic identification. To overcome this problem, the present study evaluated the amplification refractory mutation system (ARMS)-PCR analysis method to discriminate closely related species, which utilizes specific primers that have a base pair change within three bases closest to the SNP site. The aim of this study was to develop a simple and precise DNA-based method for molecular authentication of C. wilfordii when compared with the highly similar species C. auriculatum. Molecular authentication of C. wilfordii and C. auriculatum was achieved using specific modified primers for DNA sequences of chloroplast TrnL-F and nuclear internal transcribed spacer (ITS) regions. A species-specific SNP was detected for each of the two species, and mismatched ARMS-PCR was conducted to specifically identify the SNP site. Plant samples collected from different locations were used to validate the selectively modified SNP markers, and the established method was determined to be effective. Therefore, this study provides a rapid and reliable method for specific identification of the medicinal plants, C. wilfordii and C. auriculatum.     

Genome-wide association mapping of resistance to eyespot disease (<Emphasis Type="Italic">Pseudocercosporella herpotrichoides</Emphasis>) in European winter wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) and fine-mapping of <Emphasis Type="Italic">Pch1</Emphasis>

Key message

Genotypes with recombination events in the Triticum ventricosum introgression on chromosome 7D allowed to fine-map resistance gene Pch1, the main source of eyespot resistance in European winter wheat cultivars.

Abstract

Eyespot (also called Strawbreaker) is a common and serious fungal disease of winter wheat caused by the necrotrophic fungi Oculimacula yallundae and Oculimacula acuformis (former name Pseudocercosporella herpotrichoides). A genome-wide association study (GWAS) for eyespot was performed with 732 microsatellite markers (SSR) and 7761 mapped SNP markers derived from the 90 K iSELECT wheat array using a panel of 168 European winter wheat varieties as well as three spring wheat varieties and phenotypic evaluation of eyespot in field tests in three environments. Best linear unbiased estimations (BLUEs) were calculated across all trials and ranged from 1.20 (most resistant) to 5.73 (most susceptible) with an average value of 4.24 and a heritability of H ² = 0.91. A total of 108 SSR and 235 SNP marker–trait associations (MTAs) were identified by considering associations with a ?log₁₀ (P value) ≥3.0. Significant MTAs for eyespot-score BLUEs were found on chromosomes 1D, 2A, 2D, 3D, 5A, 5D, 6A, 7A and 7D for the SSR markers and chromosomes 1B, 2A, 2B, 2D, 3B and 7D for the SNP markers. For 18 varieties (10.5%), a highly resistant phenotype was detected that was linked to the presence of the resistance gene Pch1 on chromosome 7D. The identification of genotypes with recombination events in the introgressed genomic segment from Triticum ventricosum harboring the Pch1 resistance gene on chromosome 7DL allowed the fine-mapping of this gene using additional SNP markers and a potential candidate gene Traes_7DL_973A33763 coding for a CC-NBS-LRR class protein was identified.

     

Association analysis of the glutelin synthesis genes <Emphasis Type="Italic">GluA</Emphasis> and <Emphasis Type="Italic">GluB1</Emphasis> in a <Emphasis Type="Italic">Japonica</Emphasis> rice collection

Glutelin is the most significant seed storage protein and is regarded as an important nutrient quality trait in rice. Research on the genetic basis of the glutelin content distinction in rice will provide more choices for the diets of people with kidney disease and diabetes. The GluA and GluB1 genes play important roles in the process of glutelin synthesis. In this study, 128 Japonica rice accessions with wide geographic distributions were collected to construct the association panel. Among all the 128 accessions, both sequences of the GluA and GluB1 genes were obtained, and nucleotide polymorphisms were detected. A total of 46 SNPs and eight InDels, six SNPs and four InDels were found in the GluA and GluB1 gene sequences, respectively. Eight haplotypes and two haplotypes were classified based on the SNPs in the coding region of the GluA and GluB1 genes, respectively. Moreover, the association of the polymorphic sites in the two genes with glutelin content in the tested population was estimated. The results revealed that five SNPs in the GluA gene, one SNP and one InDel in the GluB1 gene were associated with glutelin content at a significant level (P < 0.01). Corresponding markers were also designed to check the alleles of GluA and GluB1 genes. These results suggested that polymorphisms in the GluA and GluB1 genes in rice could be utilized in molecular marker-assisted selection to improve the nutrient quality of rice breeding programmes.     

Comparative analysis of the effectiveness of STR and SNP markers for intraspecific and interspecific differentiation of the genus <Emphasis Type="Italic">Ovis</Emphasis>

A comparative study of the informativeness of SNP and STR markers for interspecific and intraspecific differentiation of the two species of the genus Ovis, snow sheep (O. nivicola) and domestic sheep (O. aries), was conducted. Eleven STR loci combined into two multiplex panels were examined. SNP analysis was performed with the DNA microarray OvineSNP50K BeadChip featuring 54241 SNPs. The possibility of clear differentiation of the studied Ovis species with both types of genetic markers was demonstrated. The advantages of SNP markers for intraspecific differentiation of the O. aries breeds and O. nivicola geographical groups were revealed. The areas of application of the studied types of DNA markers are discussed.     

Complete chloroplast genome sequence of <Emphasis Type="Italic">Capsicum</Emphasis><Emphasis Type="Italic">baccatum</Emphasis> var. <Emphasis Type="Italic">baccatum</Emphasis>

Molecular markers derived from the complete chloroplast genome can provide effective tools for species identification and phylogenetic resolution. Complete chloroplast (cp) genome sequences of Capsicum species have been reported. We herein report the complete chloroplast genome sequence of Capsicum baccatum var. baccatum, a wild Capsicum species. The total length of the chloroplast genome is 157,145 bp with 37.7 % overall GC content. One pair of inverted repeats, 25,910 bp in length, was separated by a small single-copy region (17,974 bp) and large single-copy region (87,351 bp). This region contains 86 protein-coding genes, 30 tRNA genes, 4 rRNA genes, and 11 genes contain one or two introns. Pair-wise alignments of chloroplast genome were performed for genome-wide comparison. Analysis revealed a total of 134 simple sequence repeat (SSR) motifs and 282 insertions or deletions variants in the C. baccatum var. baccatum cp genome. The types and abundances of repeat units in Capsicum species were relatively conserved, and these loci could be used in future studies to investigate and conserve the genetic diversity of the Capsicum species.     

Genome-wide single nucleotide polymorphisms (SNPs) for a model invasive ascidian <Emphasis Type="Italic">Botryllus schlosseri</Emphasis>

Invasive species cause huge damages to ecology, environment and economy globally. The comprehensive understanding of invasion mechanisms, particularly genetic bases of micro-evolutionary processes responsible for invasion success, is essential for reducing potential damages caused by invasive species. The golden star tunicate, Botryllus schlosseri, has become a model species in invasion biology, mainly owing to its high invasiveness nature and small well-sequenced genome. However, the genome-wide genetic markers have not been well developed in this highly invasive species, thus limiting the comprehensive understanding of genetic mechanisms of invasion success. Using restriction site-associated DNA (RAD) tag sequencing, here we developed a high-quality resource of 14,119 out of 158,821 SNPs for B. schlosseri. These SNPs were relatively evenly distributed at each chromosome. SNP annotations showed that the majority of SNPs (63.20%) were located at intergenic regions, and 21.51% and 14.58% were located at introns and exons, respectively. In addition, the potential use of the developed SNPs for population genomics studies was primarily assessed, such as the estimate of observed heterozygosity (H _O ), expected heterozygosity (H _E ), nucleotide diversity (π), Wright’s inbreeding coefficient (F _IS ) and effective population size (Ne). Our developed SNP resource would provide future studies the genome-wide genetic markers for genetic and genomic investigations, such as genetic bases of micro-evolutionary processes responsible for invasion success.     

The effects of polymorphisms in <Emphasis Type="Italic">growth hormone</Emphasis> and <Emphasis Type="Italic">growth hormone receptor</Emphasis> genes on production and reproduction traits in Aberdeen-Angus cattle (<Emphasis Type="Italic">Bos taurus</Emphasis> L., 1758)

The study was aimed to analyze the relation between individual genotypes and allelic variants of SNPs g.2141C>G of growth hormone gene, g.914T>A and g.257A>G of growth hormone receptor gene with growth and reproduction traits and to evaluate the populationgenetic structure in Aberdeen-Angus cattle (Bos taurus L., 1758) sample of Eastern Ukraine according SNPs studied. Allele C of SNP g.2141C>G has a positive correlation with birth weight, body stature, bigger rump, udder and total exterior evaluation score, shorter calving interval and better calve birth weight and negative correlation with calve average daily gain. Allele T of SNP g.914T>A has positive correlation with the muscle and udder size; live weight in each age, average daily gain, weight and average daily gain of calves born conform to the principle AA>TT≥TA. SNP g.257A>G showed a positive correlation for G allele with muscle size. The population is in equilibrium for SNPs g.2141C>G and g.257A>G, and in disequilibrium for SNP g.914T>A. The analysis showed no linkage disequilibrium between SNPs g.914T>A and g.257A>G. Inbreeding coefficient F_ST in Aberdeen-Angus group studied was 16.1%.     

Nucleotide polymorphisms of candidate genes of adaptive significance in the ural populations of <Emphasis Type="Italic">Larix sibirica</Emphasis> Ledeb.

The objectives of conservation and sustainable forest management require in depth study of genomes of woody plants and definition of their intraspecific genetic diversity. In recent years, an approach was developed based on the study of “candidate genes” that can potentially be involved in the formation of adaptive traits. In this study, we investigated nucleotide polymorphism of several adaptive candidate genes in the populations of Siberian larch (Larix sibirica Ledeb.) in the Urals. Representatives of this genus are among the most valuable and widely distributed forest tree species in Russia. From ten selected gene loci in the genome of L. sibirica, we isolated and investigated three loci, one of which (ABA-WDS) was sequenced in L. sibirica for the first time. The total length of the analyzed sequence in each individual amounted to 2865 bp. The length of locus alignment was from 360 bp to 1395 bp. In total, we identified 200 polymorphic positions. The most conservative is locus 4CL1-363, and the most polymorphic is locus sSPcDFD040B03103-274. The studied populations of L. sibirica are characterized by a high level of nucleotide polymorphism in comparison with other species and genuses (Picea, Pinus, Pseudotsuga, Abies) conifers plants (Hd = 0.896; π = 0.007; θ_W = 0.015). The most selectively neutral polymorphism (D _T =–0.997) was attributed to locus 4CL1-363, and polymorphism with high probability of adaptability (D _T =–1.807) was determined for the ABA-WDS locus. We identified 54 SNP markers, only five of which were nonsynonymous (9.26%) replacements. The average frequency of SNPs in the three studied loci of L. sibirica was one SNP in 53 bp. We detected unique SNP markers for eight populations, which could potentially be used to identify populations. Populations that are characterized by the highest number of unique SNP markers can be recommended for selection in order to preserve the gene pool of the species.     

A multiplexed set of microsatellite markers for discriminating <Emphasis Type="Italic">Acacia mangium</Emphasis>, <Emphasis Type="Italic">A. auriculiformis</Emphasis>, and their hybrid

In order to assist breeding and gene pool conservation in tropical Acacias, we aimed to develop a set of multipurpose SSR markers for use in both Acacia mangium and A. auriculiformis. A total of 51 SSR markers (developed in A. mangium and natural A. mangium x A. auriculiformis hybrid) were tested. A final set of 16 well-performing SSR markers were identified, six of which were species diagnostic. The markers were optimized for assay in four multiplex mixes and used to genotype range-wide samples of A. mangium, A. auriculiformis, and putative F₁ hybrids. Simulation analysis was used to investigate the power of the markers for identifying the pure species and their F₁, F₂, and backcross hybrids. The six species diagnostic markers were particularly powerful for detecting F₁ hybrids from pure species but could also discriminate the pure species from F₂ and backcross progenies in most cases (97 %). STRUCTURE analysis using all 16 markers was likewise able to distinguish these cross types and pure species sets. Both sets of markers had difficulties in distinguishing F₂ and backcross progenies. However, identifying F₁ from pure species is the current primary concern in countries where these species are planted. The SSR marker set also has direct application in DNA profiling (probability of identity?=?4.1?×?10^?13), breeding system analysis, and population genetics.     

Identification of candidate genes of QTLs for seed weight in <Emphasis Type="Italic">Brassica napus</Emphasis> through comparative mapping among <Emphasis Type="Italic">Arabidopsis</Emphasis> and <Emphasis Type="Italic">Brassica</Emphasis>species

Background

Map-based cloning of quantitative trait loci (QTLs) in polyploidy crop species remains a challenge due to the complexity of their genome structures. QTLs for seed weight in B. napus have been identified, but information on candidate genes for identified QTLs of this important trait is still rare.

Results

In this study, a whole genome genetic linkage map for B. napus was constructed using simple sequence repeat (SSR) markers that covered a genetic distance of 2,126.4 cM with an average distance of 5.36 cM between markers. A procedure was developed to establish colinearity of SSR loci on B. napus with its two progenitor diploid species B. rapa and B. oleracea through extensive bioinformatics analysis. With the aid of B. rapa and B. oleracea genome sequences, the 421 homologous colinear loci deduced from the SSR loci of B. napus were shown to correspond to 398 homologous loci in Arabidopsis thaliana. Through comparative mapping of Arabidopsis and the three Brassica species, 227 homologous genes for seed size/weight were mapped on the B. napus genetic map, establishing the genetic bases for the important agronomic trait in this amphidiploid species. Furthermore, 12 candidate genes underlying 8 QTLs for seed weight were identified, and a gene-specific marker for BnAP2 was developed through molecular cloning using the seed weight/size gene distribution map in B. napus.

Conclusions

Our study showed that it is feasible to identify candidate genes of QTLs using a SSR-based B. napus genetic map through comparative mapping among Arabidopsis and B. napus and its two progenitor species B. rapa and B. oleracea. Identification of candidate genes for seed weight in amphidiploid B. napus will accelerate the process of isolating the mapped QTLs for this important trait, and this approach may be useful for QTL identification of other traits of agronomic significance.

     

Discovery and introgression of the wild sunflower-derived novel downy mildew resistance gene <Emphasis Type="Italic">Pl</Emphasis><Subscript><Emphasis Type="Italic">19</Emphasis></Subscript> in confection sunflower (<Emphasis Type="Italic">Helianthus annuus</Emphasis> L.)

Key message

A new downy mildew resistance gene, Pl ₁₉ , was identified from wild Helianthus annuus accession PI 435414, introduced to confection sunflower, and genetically mapped to linkage group 4 of the sunflower genome.

Abstract

Wild Helianthus annuus accession PI 435414 exhibited resistance to downy mildew, which is one of the most destructive diseases to sunflower production globally. Evaluation of the 140 BC₁F_2:3 families derived from the cross of CMS CONFSCLB1 and PI 435414 against Plasmopara halstedii race 734 revealed that a single dominant gene controls downy mildew resistance in the population. Bulked segregant analysis conducted in the BC₁F₂ population with 860 simple sequence repeat (SSR) markers indicated that the resistance derived from wild H. annuus was associated with SSR markers located on linkage group (LG) 4 of the sunflower genome. To map and tag this resistance locus, designated Pl ₁₉ , 140 BC₁F₂ individuals were used to construct a linkage map of the gene region. Two SSR markers, ORS963 and HT298, were linked to Pl ₁₉ within a distance of 4.7 cM. After screening 27 additional single nucleotide polymorphism (SNP) markers previously mapped to this region, two flanking SNP markers, NSA_003564 and NSA_006089, were identified as surrounding the Pl ₁₉ gene at a distance of 0.6 cM from each side. Genetic analysis indicated that Pl ₁₉ is different from Pl ₁₇ , which had previously been mapped to LG4, but is closely linked to Pl ₁₇ . This new gene is highly effective against the most predominant and virulent races of P. halstedii currently identified in North America and is the first downy mildew resistance gene that has been transferred to confection sunflower. The selected resistant germplasm derived from homozygous BC₂F₃ progeny provides a novel gene for use in confection sunflower breeding programs.

     

A high-density linkage map with 2560 markers and its application for the localization of the male-sterile genes <Emphasis Type="Italic">ms3</Emphasis> and <Emphasis Type="Italic">ms4</Emphasis> in <Emphasis Type="Italic">Cryptomeria japonica</Emphasis> D. Don

Cryptomeria japonica pollinosis is one of the most serious allergic diseases in Japan; this is a social problem because C. japonica is the most important Japanese forestry species. In order to reduce the amount of pollen dispersed, breeding programs using trees with male-sterile genes have been implemented. High-density linkage maps with stable ordering of markers facilitate the localization of male-sterile genes and the construction of partial linkage maps around them in order to develop markers for use in marker-assisted selection. In this study, a high-density linkage map for C. japonica with 2560 markers was constructed. The observed map length was 1266.2 cM and the mean distance between adjacent markers was 0.49 cM. Using information from this high-density map, we newly located two male-sterile genes (ms3 and ms4) on the first and fourth linkage groups, respectively, and constructed partial linkage maps around these loci. We also constructed new partial linkage maps around the ms1 and ms2 loci using additional SNP markers. The closest markers to the ms1, ms2, ms3, and ms4 male-sterile loci were estSNP04188 (1.8 cM), estSNP00695 (7.0 cM), gSNP05415 (3.1 cM), and estSNP01408 (7.0 cM) respectively. These results allowed us to develop SNP markers tightly linked to the male sterile genes for use in MAS; this will accelerate the future isolation of these genes by map-based cloning approaches.     

<Emphasis Type="Italic">Cantharellus</Emphasis> sect. <Emphasis Type="Italic">Amethystini</Emphasis> in Asia

In this contribution on the genus Cantharellus in Asia, C. subvaginatus is described from the Republic of Korea as a close relative to the Chinese C. vaginatus, which is here reported for the first time from India. Both species are here placed in Cantharellus subg. Cantharellus sect. Amethystini, together with the Indian C. pseudoformosus (syn.: C. umbonatus) and the Malayan C. subamethysteus. As such, Asia has suddenly become the continent with the highest diversity for Amethystini. Species delimitation in sect. Amethystini is molecularly supported by a combined phylogenetic analysis of rDNA sequences obtained for LSU and ITS and additionally suggests the existence of a still undescribed species in North America. Character variability is discussed for all known members of Amethystini, including atypical specimens of the North American C. lewisii that are morphologically more reminiscent of the South Korean C. subvaginatus.     

A <Emphasis Type="Italic">bean common mosaic virus</Emphasis> (BCMV)-resistance gene is fine-mapped to the same region as <Emphasis Type="Italic">Rsv1</Emphasis>-<Emphasis Type="Italic">h</Emphasis> in the soybean cultivar Suweon 97

Key message

In the soybean cultivar Suweon 97, BCMV-resistance gene was fine-mapped to a 58.1-kb region co-localizing with the Soybean mosaic virus (SMV)-resistance gene, Rsv1-h raising a possibility that the same gene is utilized against both viral pathogens.

Abstract

Certain soybean cultivars exhibit resistance against soybean mosaic virus (SMV) or bean common mosaic virus (BCMV). Although several SMV-resistance loci have been reported, the understanding of the mechanism underlying BCMV resistance in soybean is limited. Here, by crossing a resistant cultivar Suweon 97 with a susceptible cultivar Williams 82 and inoculating 220 F₂ individuals with a BCMV strain (HZZB011), we observed a 3:1 (resistant/susceptible) segregation ratio, suggesting that Suweon 97 possesses a single dominant resistance gene against BCMV. By performing bulked segregant analysis with 186 polymorphic simple sequence repeat (SSR) markers across the genome, the resistance gene was determined to be linked with marker BARSOYSSR_13_1109. Examining the genotypes of nearby SSR markers on all 220 F₂ individuals then narrowed down the gene between markers BARSOYSSR_13_1109 and BARSOYSSR_13_1122. Furthermore, 14 previously established F_2:3 lines showing crossovers between the two markers were assayed for their phenotypes upon BCMV inoculation. By developing six more SNP (single nucleotide polymorphism) markers, the resistance gene was finally delimited to a 58.1-kb interval flanked by BARSOYSSR_13_1114 and SNP-49. Five genes were annotated in this interval of the Williams 82 genome, including a characteristic coiled-coil nucleotide-binding site-leucine-rich repeat (CC-NBS-LRR, CNL)-type of resistance gene, Glyma13g184800. Coincidentally, the SMV-resistance allele Rsv1-h was previously mapped to almost the same region, thereby suggesting that soybean Suweon 97 likely relies on the same CNL-type R gene to resist both viral pathogens.

     

Phylogenetic Relationships within <Emphasis Type="Italic">Phyllophaga</Emphasis> Harris (sensu <Emphasis Type="Italic">lato</Emphasis>) (Coleoptera: Melolonthidae,Melolonthinae) with Emphasis on <Emphasis Type="Italic">Listrochelus</Emphasis> Blanchard

As partial results of a long-term project for the revision of the supraspecific classification of the American Melolonthini, using phylogenetic methods, interesting information on the relationships between the subgeneric groups of Phyllophaga Harris proposed by Saylor were obtained. The genus Listrochelus was described by Blanchard in 1851. However, in 1940, Saylor reduced it as a subgenus of Phyllophaga. The objective of the present study is to confirm the monophyly of Listrochelus by means of a phylogenetic analysis. A total of 132 species were analyzed; 31 species of them belong to Listrochelus, 76 are from other groups of Phyllophaga, and 25 species are from the outgroup. A morphological matrix with 281 characters was codified. A traditional search with 1000 iterations was performed in TNT. Branch support was investigated using the bootstrap method. Parsimony analysis resulted in ten equally parsimonious trees. The topology obtained in the strict consensus tree shows that the limits of Listrochelus are very clear (bootstrap 99%), supported by five synapomorphies and a combination of eight character states that are not exclusive to the group. Based on the hypothesis obtained, the restitution of the genus Listrochelus is proposed.     

Adult plant stripe rust resistance gene <Emphasis Type="Italic">Yr71</Emphasis> maps close to <Emphasis Type="Italic">Lr24</Emphasis> in chromosome 3D of common wheat

Australian cultivar Sunco carries three adult plant stripe rust resistance genes. One of these genes corresponded to Yr18 in chromosome 7DS; the second, YrCK, was mapped on chromosome 2D. Here, we describe the characterization of the third adult plant resistance (APR) gene from Sunco. Sunco/2*Avocet S-derived lines SA65 (resistant) and SA67 (susceptible) were crossed and a recombinant inbred line F₆ population was generated. Monogenic segregation among SA65/SA67-derived RIL population was demonstrated and the resistance locus was designated YrSA3. Selective genotyping using an iSelect 90 K Infinium SNP array and SSR markers located YrSA3 on chromosome 3D. Development of KASP markers for SNP loci showing association with YrSA3 allowed construction of a genetic map harboring the resistance gene. Ten KASP markers (KASP_8306, KASP_9142, KASP_10438, KASP_16434, KASP_17207, KASP_20836, KASP_23518, KASP_23615, KASP_57983 and KASP_63653), one SSR marker (gwm114b) and Lr24/Sr24 were mapped 1.8 cM distal to YrSA3. Comparison of marker data indicated that the previously named seedling stripe rust resistance gene Yr45 was located proximal to YrSA3, and therefore the latter was formally designated Yr71. Two recombinants carrying Lr24/Sr24 and Yr71 in combination were identified for use as donor sources in wheat breeding programs. The robustness of gwm114b, KASP_16434, KASP_17207 and KASP_20836 for marker-assisted selection of these genes was demonstrated through tests on 74 Australian wheat cultivars.     

Molecular mapping of a rust resistance gene <Emphasis Type="Italic">R</Emphasis><Subscript><Emphasis Type="Italic">14</Emphasis></Subscript> in cultivated sunflower line PH 3

Sunflower, the fifth largest oilseed crop in the world, plays an important role in human diets. Recently, sunflower production in North America has suffered serious yield losses from newly evolved races of sunflower rust (Puccinia helianthi Schwein.). The rust resistance gene, designated R ₁₄ , in a germplasm line PH 3 originated from a wild Helianthus annuus L. population resistant to 11 rust races. PH 3 has seedling with an extraordinary purple hypocotyl color. The objectives of this study were to map both the R ₁₄ rust resistance gene and the purple hypocotyl gene-designated PHC in PH 3, and to identify molecular markers for marker-assisted breeding for sunflower rust resistance. A set of 517 mapped SSR/InDel and four SNP markers was used to detect polymorphisms between the parents. Fourteen markers covering a genetic distance of 17.0 cM on linkage group (LG) 11 were linked to R ₁₄ . R ₁₄ was mapped to the middle of the LG, with a dominant SNP marker NSA_000064 as the closest marker at a distance of 0.7 cM, and another codominant marker ORS542 linked at 3.5 cM proximally. One dominant marker ZVG53 was linked on the distal side at 6.9 cM. The PHC gene was also linked to R ₁₄ with a distance of 6.2 cM. Chi-squared analysis of the segregation ratios of R ₁₄ , PHC, and ten linked markers indicated a deviation from an expected 1:2:1 or 3:1 ratio. The closely linked molecular or morphological markers could facilitate sunflower rust-resistant breeding and accelerate the development of rust-resistant hybrids.