Search Results (1,163)

Sweet cherry (Prunus avium L.) exhibits relatively low genetic diversity because of the self-compatibility of some varieties and repeated crossings of the same genotypes. High-quality markers are therefore needed for their reliable discrimination. However, the most currently used simple sequence repeat (SSR) markers offer only limited resolution for genotyping purposes. Here, thirty new highly polymorphic SSR markers were extracted from whole-genome sequences of 299 sweet cherry genotypes. Then, 16 highly polymorphic SSR markers were selected, multiplexed into one PCR, and successfully verified on a collection containing 294 unique genotypes. Compared with the set of 16 SSR markers recommended by the European Cooperative Programme for Plant Genetic Resources (ECPGR) for sweet cherry genotyping, our newly developed system has a seven orders of magnitude lower probability of the random identity of two genetically distinct samples than the ECPGR set (10⁻¹⁹ vs. 10⁻¹²). This higher resolution not only enables more precise genotyping but can also be successfully used for parentage or population analyses. This new and unique one-tube approach for sweet cherry genotyping will substantially simplify genotyping workflows, minimize errors, and save labor, time, and cost. Full article

Taxus cuspidata is a threatened subalpine conifer in South Korea, necessitating evidence-based restoration strategies to counter the impacts of climate change. In this study, we assessed 13 natural populations using 15 polymorphic nuclear simple sequence repeat (nSSR) markers developed in Taxus species and spatial autocorrelation analysis to provide a scientific foundation for conservation. The results showed an intermediate level of genetic diversity, with the Mt. Gariwangsan population exhibiting higher diversity. This highlights its priority as a source for restoration materials. Bayesian clustering supported four distinct management units. Spatial autocorrelation analysis revealed significant positive genetic structure within approximately 50 m, indicating a localized genetic patch size. Based on these results, we suggest maintaining a minimum 50 m sampling distance during seed collection to avoid collecting closely related individuals and to reduce the risk of genetic homogeneity in restoration materials. Such restoration strategies informed by spatial genetic structure and broader genetic data are critical for enhancing the long-term resilience of T. cuspidata in the face of accelerating environmental shifts. Full article

Cibotium barometz (L.) J. Sm., a medicinally significant fern in traditional Chinese medicine, is little explored at the genomic level regarding its bioactive compounds. Using an integrated approach combining Illumina and PacBio sequencing technologies, we profiled its root, rachis, and pinna transcriptomes, identifying 12,718, 21,341, and 11,441 unigenes, respectively. Our analysis systematically characterized the transcriptional features of transcription factors (TFs), simple sequence repeats (SSRs), long non-coding RNAs (lncRNAs), and differentially expressed genes (DEGs). Enrichment analyses highlighted the roles of highly expressed unigenes in secondary metabolism. Seventeen key enzymes involved in polysaccharide biosynthesis showed tissue-specific expression patterns. Notably, total polysaccharide content correlated positively with UDP-arabinose 4-epimerase (UXE) expression but negatively with phosphoglucomutase (PGM) and 3,5-epimerase/4-reductase (UER1). Flavonoid accumulation inversely correlated with chalcone synthase (CHS) expression. Two lignin pathways (H-lignin and G-lignin) were characterized, with phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H), and cinnamyl alcohol dehydrogenase (CAD) as key genes. The absence of ferulate-5-hydroxylase (F5H) explains the undetected S-lignin pathway. Regulatory network analysis revealed positive correlations between PAL expression and NAC72/NAC78/WRKY35 and C4H expression and WRKY65/WRKY69/WRKY71, while a negative correlation was revealed between flavonoid 3′,5′-hydroxylase (F3′5′H) and MYB3R4. This study provides comprehensive transcriptomic insights into C. barometz bioactive compound biosynthesis, serving as a foundation for mechanistic research. Full article

Sympatric species share identical geographical spaces, climatic conditions and survival pressures. Comparative chloroplast genomes among Anna and Lysionotus sympatric species enable exploration of genome-wide evolutionary dynamics of sympatric species. In this study, we assembled and annotated 10 complete chloroplast genomes, representing sympatric species distributed along the Sino-Vietnamese border. We conducted a comparison of chloroplast genomes, characterized their adaptive evolution and used multiple methods to clarify their phylogenetic relationships. Key findings included the following: 1. The number of CDs, rRNA and tRNA varied among different species, whereas they were relatively conserved between the two genera; 2. psaB-psaA, trnL-UAG and ndhD-psaC were identified as potential molecular markers for Anna species, with clpP and ycf1 proposed as effective molecular markers for Lysionotus species; 3. the types of simple sequence repeats (SSRs) and large sequence repeats (LRSs) showed a higher conservation in Lysionotus compared with Anna; 4. the codon usage preferences of the two genera showed convergent evolutionary trends and natural selection played a dominant role, with ycf1 and atpH being confirmed as significantly positively selected genes; 6. phylogenetic analyses using multiple approaches (ML, BI and NJ) consistently verified that Anna and Lysionotus each formed a well-supported monophyletic group. This study offers molecular insights into adaptation and differentiation patterns among distinct plant genera inhabiting the same extreme habitat. Full article

Sugar beet (Beta vulgaris L.) is an economically important crop that accounts for approximately 20% of global sugar production. The success of future breeding programs depends on the effective utilization of existing genetic resources. The aim of this study was to assess the genetic diversity and population structure of 192 sugar beet (Beta vulgaris L.) genotypes, including commercial cultivars and accessions obtained from the USDA gene bank, using SCoT and ISSR molecular markers, and to identify potential genetic resources for sugar beet breeding programs. In this study, a total of 192 sugar beet genotypes, including 187 accessions from the USDA (U.S. Department of Agriculture) gene bank and 5 commercial cultivars, were evaluated for genetic diversity using Start Codon Targeted (SCoT) and Inter Simple Sequence Repeat (ISSR) markers. A total of 68 scorable bands were obtained from five SCoT and three ISSR primers, and all bands were found to be polymorphic (100% polymorphism). Parameters such as polymorphic information content (PIC), Nei’s genetic diversity, and Shannon’s index indicated a high level of variation within the gene pool, with SCoT markers being more informative than ISSR markers. Dendrogram analyses based on Nei’s genetic distance revealed that the populations were separated into two main groups, while the sub-clusterings contained broad genetic variation. STRUCTURE analysis identified four (K = 4) populations for the SCoT data and three (K = 3) populations for the ISSR data; the inclusion of a high number of individuals in the admixture population indicated extensive gene flow. Principal component analysis (PCA) revealed both homogeneous groups and differentiated genotypes contributing to within-population diversity. The results demonstrate that the combined use of SCoT and ISSR markers provides powerful and complementary tools for assessing genetic diversity in sugar beet. The findings provide a solid scientific basis for the development of new, high-yielding and high-quality sugar beet cultivars as well as for the conservation of existing genetic resources. Molecular data constitute an important reference for guiding sugar beet breeding programs and for the effective utilization of genetic resources. Full article

Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system is a simple and powerful tool, which enables gene knockout or insertion of new gene cassettes. This method has been applied to various plants and is used for crop improvement. Cultivated strawberry (Fragaria× ananassa), a member of the Rosaceae family, is a high-value horticultural crop. However, its complex octoploid genome poses challenges for precise genome editing in polyploids. This study aimed to establish a protoplast-based, DNA-free genome-editing approach in the cultivated octoploid strawberry. We optimized the culture conditions and enzyme combinations to enable efficient protoplast isolation from the fully developed leaves. The highest protoplast yield was obtained with a Murashige and Skoog medium containing 1% sucrose and 2 mg/L 6-benzylaminopurine (BA), along with enzymatic digestion using 2% Viscozyme, 1% Celluclast, and 1% Pectinex. Transient transfection conditions were optimized using a green fluorescence protein (GFP) plasmid with the highest expression efficiency (up to 52.5%) observed using 40% PEG 4000 and 20 min incubation. Under these conditions, Cas9 ribonucleoproteins (RNPs) targeting the FaPDS and FaPG1 genes were introduced, and guide RNA (gRNA) screening was conducted by targeted deep sequencing. In conclusion, this study successfully demonstrated protoplast isolation and DNA-free CRISPR/Cas9 genome editing in cultivated strawberry. The optimized protoplast-based system provides a valuable platform for functional genomics and molecular breeding efforts in octoploid strawberries. Full article

Wheat is among the most important staple crops worldwide; however, its yield and quality are severely threatened by stripe rust caused by Puccinia striiformis f. sp. tritici (Pst). CH806 is a Thinopyrum intermedium-derived resistant breeding line developed in our laboratory that is highly resistant to the prevalent Chinese Pst races CYR32, CYR33, and CYR34 in field trials. A genetic population was developed by crossing CH806 with the susceptible cultivar Chuanmai 24. Phenotypic evaluation of the progeny under field conditions revealed segregation for stripe rust resistance in the F₂ generation. On the basis of the resistance phenotypes of the F₂ and F_2:3 populations, homozygous resistant and homozygous susceptible F₂ individuals were selected to construct resistant and susceptible DNA bulks, respectively, for genotyping using the Wheat 120K SNP array. Bulked segregant analysis indicated that the most significant SNPs were predominantly clustered on chromosome 4A. Subsequently, publicly available simple sequence repeat (SSR) markers on chromosome 4A and newly developed SSR markers within the candidate region that were enriched for polymorphic SNPs were used for linkage analysis. The resistance locus, temporarily designated YrCH806, was mapped to an interval flanked by markers Xwmc48/Xwmc89 and SSR4A-60, with genetic distances of 4.4 cM and 2.5 cM, respectively, corresponding to a physical position of 515.8–574.7 Mb on the wheat reference genome. The closest flanking marker, SSR4A-60, was successfully converted into a Kompetitive Allele-Specific PCR (KASP) marker. This high-throughput marker was subsequently utilized to screen a panel of wheat germplasms for the distribution of YrCH806. This study provides a novel resistance source and associated molecular markers for improving stripe rust resistance in wheat breeding programs. Full article

We investigate time-resolved wave-packet transport in monolayer graphene patterned with asymmetric arrays of circular electrostatic scatterers. Using the Dirac continuum model with a split-operator scheme, we track how transmission evolves with scatterer radius and polarity sequence. To this end, we consider three potential configurations (Samples 1–3). The results reveal a geometry-controlled crossover from near-ballistic propagation at small radii to interference-dominated backscattering at large radii. Sample 1, where the potential exhibit two parallel lines of circles, each line sharing the same potential sign, preserves the highest transmission. Conversely, in Sample 3, where potential signs are intercalated between circles of the same line, the dwell time increases, which produces stronger confinement. As the radius increases, pronounced temporal oscillations emerge due to repeated internal reflections (similar to Fabry–Pérot interferometer), and the radius dependence of the saturated transmission probability exhibits anti-resonant dips that are tunable by geometry and potential magnitude. These behaviors establish simple design rules for graphene nanodevices: small-radius Sample 1 for high-throughput transport, Sample 2 (with inverted potential signs as compared to Sample 1) for broadband suppression, and Sample 3 for finely tunable, interference-based confinement. Full article

Pseudolysimachion pyrethrinum var. gasanensis (Gasan spike speedwell) is a valuable Korean endemic variety with significant horticultural potential. Despite its morphological distinctiveness, its taxonomic status and evolutionary position have remained a subject of debate. In this study, we assembled and characterized the first complete chloroplast (cp) genome of P. pyrethrinum var. gasanensis using high-throughput sequencing. The complete plastome is 152,251 bp in length, exhibiting a typical quadripartite structure with a large single-copy (LSC) region (83,191 bp), a small single-copy (SSC) region (17,690 bp), and two inverted repeats (IRs) (25,685 bp each). The genome contains 133 genes, including 88 protein-coding, 37 tRNA, and 8 rRNA genes. Genomic analysis identified 42 simple sequence repeat (SSR) units across 38 distinct loci, predominantly mononucleotide A/T motifs, which serve as potential molecular markers for variety-level identification. Selective pressure analysis revealed that the majority of protein-coding genes are under strong purifying selection (Ka/Ks < 1.0), emphasizing the evolutionary stability of the plastome. Comparative analysis of IR boundaries using IRscope revealed a high degree of structural conservation among Pseudolysimachion species, with minor variations at the junction sites. Phylogenetic analysis based on 18 complete plastomes strongly supported the monophyly of the genus Pseudolysimachion (Bootstrap = 100%) and placed P. pyrethrinum var. gasanensis as a sister to the European P. spicatum. These genomic resources provide a foundational tool for the molecular breeding, systematic conservation, and sustainable utilization of this endemic variety, while offering clarity to its taxonomic classification within the tribe Veroniceae. Full article

In this study, a targeted SSR (Simple Sequence Repeat) marker resource was developed based on genes and protein families associated with pathogen- and pest-related defense–resistance mechanisms in Camellia sinensis. Forty-one genes and protein families reported to show upregulation, increased expression, or functional validation under disease and pest stress were selected, and the corresponding 195 loci were mapped onto the Camellia sinensis cv. Shuchazao genome. SSR screening within gene bodies and gene-flanking regions (±5 kb) identified 5197 SSR loci. Putative QTL hotspot regions were defined using locus-based sliding-window analysis, Z-score calculations, and permutation tests, yielding 633 SSRs filtered at the 99% and 95% significance thresholds. Proteome-wide scans based on conserved amino acid motifs identified multiple loci within the WRKY, NAC, LRR, PRX, and CHI families, and Random Forest analysis was used to prioritize SSRs within these families. Finally, 386 SSR primer sets were designed and evaluated by in silico PCR across six tea genomes. Of these, 245 primers produced amplicons in more than one genome, and 124 exhibited polymorphic information content values greater than 0.500. Overall, the developed SSR panels represent a biologically contextualized and experimentally transferable marker resource targeting defense–resistance-associated genic and gene-proximal regions. Full article

Rhizoctonia solani anastomosis group (AG)-2-2IIIB and AG-4HGI are the main pathogens causing sugar beet seedling damping-off and crown and root rot disease. In this study, 1232 loci of simple sequence repeats (SSRs) were obtained via transcriptome sequencing, with 592 from AG-2-2IIIB and 640 from AG-4HGI. Fourteen and twenty loci of SSRs were selected for studying the genetic structure of the AG-2-2IIIB and AG-4HGI populations, respectively. A population of 134 strains of AG-2-2IIIB and 145 strains of AG-4HGI, sampled from three geographic regions in China, indicated that both AG-2-2IIIB and AG-4HGI had a high level of genetic diversity, and that the selected SSR markers could reliably capture the genetic variation. Genetic analysis indicated that the individual strains of AG-2-2IIIB and AG-4HGI randomly mated within their respective population, and that a considerable degree of inbreeding was present among the populations. High to moderate gene flow and low to moderate population subdivision were detected among the populations of AG-2-2IIIB and AG-4HGI, which indicated that weak differentiation existed in these two subgroups. In addition, a founder effect (genetic drift) or a bottleneck effect was inferred to have occurred in the AG-4HGI population. This study provides the first analysis of the population genetic structure of AG-2-2IIIB and AG-4HGI associated with sugar beet seedling damping-off and crown and root rot disease, and the present results offer useful guidance for developing effective integrated disease management. Full article

Rye (Secale cereale L.) is a small-grain cereal traditionally cultivated under low-input conditions, where locally adapted populations have contributed substantially to the maintenance of genetic diversity. Despite this importance, Greek rye germplasm has received limited attention at the molecular level. In the present study, 33 rye accessions, including gene bank landraces, locally cultivated populations and one commercial variety, were analyzed using inter-simple sequence repeat (ISSR), start codon-targeted (SCoT), and exon-based amplified polymorphism (EBAP) markers. All three marker systems generated high proportions of polymorphic loci and comparable estimates of expected heterozygosity, indicating considerable genetic variability within the studied material. Multivariate analyses revealed moderate population structuring and consistently identified a small number of genetically divergent accessions, most notably T-492, K-163, and K-166. No clear clustering according to geographical origin was detected, as in most cases of landraces or local populations. Taken together, the results provide a detailed molecular overview of Greek rye germplasm—which has never been performed before for Greek rye genetic material—and offer a useful basis for conservation priorities and future pre-breeding efforts. Full article

Triticale (×Triticosecale Wittmack), a synthetic hybrid of wheat (Triticum spp.) and rye (Secale cereale), is a valuable dual-purpose crop for its high yield and stress tolerance. Introducing beneficial alien chromatin is crucial for expanding genetic diversity and improving cultivars. This study aimed to introduce Thinopyrum intermedium St genome chromatin into hexaploid triticale via trigeneric hybridization to develop novel germplasm. Six stable lines were selected from crosses between an octoploid wheat-Th. intermedium partial amphiploid line Maicao 8 and a hexaploid triticale cultivar Hashi 209. Agronomic traits were evaluated over two cropping seasons, revealing that the translocation lines exhibited superior agronomic performance compared to the parental triticales. These lines showed longer spikes, higher tiller numbers, and increased grain protein content, without compromising thousand-kernel weight. Cytogenetic analysis using sequential multicolor genomic in situ hybridization (smGISH), fluorescence in situ hybridization (FISH), and oligonucleotide probes, alongside validation with species-specific molecular markers, identified all six lines as St-R terminal translocation lines containing 14 rye chromosomes. Three lines carried a small terminal St segment on chromosome 1R, while the other three carried St segments on both 1RL and 4RS chromosomes. This work demonstrates that trigeneric hybridization is an effective strategy for inducing intergeneric recombination between Thinopyrum intermedium and rye chromosomes, leading to stable, small-segment terminal translocations. The developed St-R translocation lines represent a novel and valuable germplasm resource for enriching genetic diversity and breeding improved triticale cultivars with enhanced yield and quality traits. Full article

Background/Objectives: The Fagopyrum dibotrys complex is a specialized high-altitude lineage in southwestern China with medicinal and breeding potential, but species delimitation remains unresolved. Methods: We sequenced 26 complete chloroplast genomes from the Hengduan Mountains to the Yunnan–Guizhou Plateau, analyzing genomic structures, variation patterns, and phylogenetic relationships. Results: All genomes exhibited typical quadripartite structures (152,213–160,302 bp), containing 133 genes (88 protein-coding, 8 rRNA, and 37 tRNA) with GC content of 37.9%. Collinearity analysis revealed highly conserved structures without structural rearrangements. Variations were concentrated in the large single-copy(LSC)/small single-copy(SSC) non-coding regions, with hotspots at ycf4–cemA and ndhF–rpl32. Codon usage showed an A/U bias, with leucine being most abundant and cysteine the least. Simple sequence repeats (SSRs) were predominantly mononucleotide repeats enriched in the LSC, while long repeats were mainly palindromic/forward. Maximum likelihood and Bayesian phylogenies consistently resolved three clades: Tibetan high-altitude specialists, limestone specialists, and a widespread Hengduan–Yunnan–Guizhou clade, with geographic clustering indicating isolation as the primary differentiation driver. Conclusions: This study refines the phylogenetic resolution of the F. dibotrys complex and identifies informative chloroplast markers, providing a genomic foundation for reliable species delimitation, evolutionary inference, and conservation management of this medicinal lineage. Full article

This study addresses a critical gap in seismic design by quantifying how plan asymmetry and multiple earthquake sequences interact to affect the nonlinear reaction of reinforced concrete (RC)-framed models. While earthquake-resistant design provisions have evolved, most current codes are based on single-event assumptions and simplified symmetry considerations, overlooking the cumulative effects of repeated ground motions observed in recent international studies. In this research, symmetrical and asymmetrical low-rise RC buildings are analyzed through nonlinear dynamic simulations, with both single- and multiple-event ground excitations considered for comparison. The analyses incorporate three-dimensional ground motions in horizontal and vertical orientations, while explicitly modeling the nonlinear inelastic response of RC sections under severe seismic demands. The evaluation of elastoplastic findings relies on normalized indices, by considering a simple dimensionless parameter to quantify the physical symmetry or asymmetry of the RC models. Results show that increasing plan asymmetry amplifies inter-story drift, torsional rotations, and plastic hinge concentrations, particularly under successive earthquake sequences. These findings indicate that existing design provisions may underestimate the vulnerability of irregular RC buildings. This work is among the first to integrate plan asymmetry and multi-event seismic loading into a unified evaluation framework, offering a novel tool for refining earthquake-resistant design standards. Full article