Search Results (545)

Veronica nakaiana Ohwi and Veronica pusanensis Y.N.Lee are rare and endemic plants native to Korea, with increasing interest in their cultivation and breeding for industrial applications. Mutation breeding is important for developing horticultural cultivars. Among mutation breeding techniques, chemical mutagenesis is particularly accessible and effective. Colchicine-induced mutagenesis was performed in vivo at various concentrations (0.2%, 0.4%, 0.6%, 0.8%, and 1.0%) and treatment durations (1, 2, 3, 4, and 5 h). Both V. nakaiana Ohwi and V. pusanensis Y.N.Lee showed the highest survival (23.4% and 34.8%, respectively) and mutation (1.6% and 0.5%, respectively) rates with 0.2% colchicine. Flow cytometry and chromosome number analyses revealed mutants as tetraploid, with chromosome numbers ranging from 2n = 66 to 2n = 68. Stomatal analysis indicated increased stomatal length and width and decreased stomatal density. Morphological analysis of the mutants revealed that the leaves of V. nakaiana Ohwi and V. pusanensis Y.N.Lee were significantly larger and had different shapes compared to the control. This study successfully generated new mutant plants of two Veronica species using chemical mutagen treatment, which could be utilized as new genetic resources for various Veronica species breeding programs in the future. Full article

Neo-tetraploid rice is a highly fertile variety created from autotetraploid rice. It demonstrates stronger heterosis and produces stable hybrid progeny. However, there is insufficient data regarding abiotic stress in neo-tetraploid hybrid progeny, especially in relation to salt stress. Two hybrid progenies, high salt-resistance tetraploid rice hybrid progeny (HSRTH) and low salt-resistance tetraploid rice hybrid progeny (LSRTH), were generated by crossing the neo-tetraploid rice cultivars ‘Huaduo 3’ and ‘Huaduo 8’ with the autotetraploid rice Huanghuazhan-4x. Here, we assessed the germination characteristics and seedling growth of two neo-tetraploid hybrids at six NaCl concentrations: 0, 50, 100, 150, 200, and 250 mmol/L. HSRTH demonstrated a higher tolerance to salt stress, achieving a grain germination rate of 48.00 ± 2.63% compared to LSRTH, which reached only 5.00 ± 1.41% under a 250 mmol/L NaCl treatment. Cytological observations showed that the root tip differentiation zone and coleoptiles of HSRTH were less affected by NaCl stress treatment, resulting in fewer cortical cell abnormalities, decreased stele issues, and fewer rhizodermis cell problems, such as shrinkage. Gene expression analysis revealed nine genes that showed differential expression in HSRTH compared to LSRTH. Our study demonstrated that HSRTH showed strong salt stress tolerance, providing a basis for selecting salt-resistant rice germplasm and offering insights for developing salt-tolerant rice varieties using neo-tetraploid resources. Full article

Phenolic compounds contribute significantly to the nutritional and functional properties of wheat, particularly due to their antioxidant activity. In this study, a genome-wide association study was conducted to elucidate the genetic basis of total phenolic content (TPC) and antioxidant activity (AA) in a panel of 144 tetraploid wheat accessions representing diverse subspecies. The panel was evaluated under two different environments, located in Chile and Italy, to assess the influence of genotype, environment, and their interaction. Significant variability was observed for both TPC and AA, with TPC ranging from 0.26 to 0.82 mg gallic acid equivalent (GAE)/g and AA from 0.04 to 0.99 µmol Trolox equivalent (TE)/g. Substantial phenotypic variation and high broad-sense heritability were observed for both traits, underscoring the predominant genetic control. The genome-wide association study, using a mixed linear model (MLM), and the Bayesian information and Linkage-disequilibrium Iteratively Nested Keyway (BLINK) approaches identified 17 significant marker–trait associations, including quantitative trait loci on chromosomes 2B, 3A, 4B, 5A, 5B, and 6B. Notably, QTLs on chromosome 5A were co-localized for both TPC and AA, suggesting potential pleiotropic loci. Candidate genes linked to these loci included flavonol 3-sulfotransferase and peptidylprolyl isomerase, which are involved in phenylpropanoid metabolism and oxidative stress response, respectively. These findings offer valuable insights into the genetic basis of wheat phenolic traits and provide molecular targets for the development of biofortified cultivars through marker-assisted selection. Full article

Although previous studies have investigated the reproductive (performance and mode) and lifespan traits of parthenogenetic Artemia, ploidy level has not been considered. Four parthenogenetic Artemia lineages, i.e., diploid, triploid, tetraploid, and pentaploid, were examined to determine the role of ploidy level under osmotic stress conditions (50, 100, and 150 ppt). Although the reproductive mode of the pentaploid lineage is unaffected by changes in salinity, it is entirely switched to oviparity in the diploid lineage at 50 ppt and in the tetraploid lineage at 100 ppt. Moreover, tetraploid reproduction is completely inhibited at 50 ppt. Although oviparity has been proposed as an adaptive strategy enhancing Artemia fitness at high salinities, the exclusive oviparous reproduction observed in the diploid parthenogenetic lineage at 50 ppt suggests that low salinity may also act as an environmental stressor, driving oviparity to ensure the next generation. On the basis of lifespan data, the tetraploid lineage presents greater euryhalinity than other ploidy levels do, whereas the pentaploid lineage is more stenohaline. Additionally, discriminant function analysis revealed that diploid and tetraploid lineages display heterogeneous reproductive/lifespan patterns across salinities, whereas triploid and pentaploid lineages exhibit homogeneous patterns within their respective groups. Our findings challenge the prevailing view that the ploidy level of parthenogenetic Artemia is correlated with tolerance to critical hypersaline conditions. In conclusion, we propose that the life history of parthenogenetic Artemia is influenced not only by ploidy level but also by the multifactorial integration of environmental conditions (particularly salinity and temperature) and local intra-variation/adaptation within isolated habitats. Full article

The immortal murine hepatic stellate cell line Col-GFP HSC was comprehensively characterized using genetic and molecular approaches. Short tandem repeat (STR) profiling and karyotyping combined with multiplex fluorescence in situ hybridization (M-FISH) confirmed the identity of the cell line and revealed no contamination. Col-GFP HSCs showed a near tetraploid karyotype. Additionally, next-generation sequencing (NGS) data, quantitative reverse transcription PCR, and Western blot analyses demonstrated robust expression of genes and proteins associated with hepatic stellate cells, including those involved in extracellular matrix remodeling and fibrogenic pathways. Phalloidin staining revealed filamentous actin patterns characteristic of stellate cells, providing additional support for their cytoskeletal organization and functional status. These findings provide strong evidence that the Col-GFP HSC cell line originates from hepatic stellate cells and can serve as a reliable in vitro model to study stellate cell biology and related pathophysiological processes. Full article

In this study, GH19 chitinase (Chi) gene family was systematically identified and characterized using genomic assemblies from four cotton species: Gossypium barbadense, G. hirsutum, G. arboreum, and G. raimondii. A suite of analyses was performed, including genome-wide gene identification, physicochemical property characterization of the encoded proteins, subcellular localization prediction, phylogenetic reconstruction, chromosomal mapping, promoter cis-element analysis, and comprehensive expression profiling using transcriptomic data and qRT-PCR (including tissue-specific expression, hormone treatments, and Fusarium oxysporum infection assays). A total of 107 GH19 genes were identified across the four species (35 in G. barbadense, 37 in G. hirsutum, 19 in G. arboreum, and 16 in G. raimondii). The molecular weights of GH19 proteins ranged from 9.9 to 97.3 kDa, and they were predominantly predicted to localize to the extracellular space. Phylogenetic analysis revealed three well-conserved clades within this family. In tetraploid cotton, GH19 genes were unevenly distributed across 12 chromosomes, often clustering in certain regions, whereas in diploid species, they were confined to five chromosomes. Promoter analysis indicated that GH19 gene promoters contain numerous stress- and hormone-responsive motifs, including those for abscisic acid (ABA), ethylene (ET), and gibberellin (GA), as well as abundant light-responsive elements. The expression patterns of GH19 genes were largely tissue-specific; for instance, GbChi23 was predominantly expressed in the calyx, whereas GbChi19/21/22 were primarily expressed in the roots and stems. Overall, this study provides the first comprehensive genomic and functional characterization of the GH19 family in G. barbadense, laying a foundation for understanding its role in disease resistance mechanisms and aiding in the identification of candidate genes to enhance plant defense against biotic stress. Full article

Rubus magurensis Wolanin, M. Nobis & Oklej. (Rosaceae), a new species from the Northern Carpathians, described and illustrated here, is a tetraploid (2n = 28) belonging to the subgenus Rubus series Micantes. Among the most characteristic features of this species are first-year stems that are almost glabrous, leaflets most often arched downward, and inflorescences leafy to the apex with a few simple oval leaves in the upper part, which make this species easy to recognise. This species resembles R. tabanimontanus Figert, from which it differs in having smaller primocane prickles, digitate to subpedate leaves, larger flowers, and inflorescences leafy to the apex. Rubus magurensis is currently known from 11 populations located in southeastern Poland (7 ATPOL 2 × 2 km units). Most of them were found in the central part of the Low Beskid Mts., with two populations located in the northwestern part of the Strzyżów Foothills. Full article

Diploid Vaccinium fuscatum is a wild blueberry species with a low chilling requirement, an evergreen growth habit, and soil adaptability to southeast US growing regions. Regardless of its potential to improve the abiotic and biotic resilience of cultivated blueberries, this species has rarely been used for blueberry breeding. One hurdle is the ploidy barrier between diploid V. fuscatum and tetraploid cultivated highbush blueberries. To overcome the ploidy barrier, vegetative shoots micro-propagated from one genotype of V. fuscatum, selected because it grew vigorously in vitro and two southern highbush cultivars, ‘Emerald’ and ‘Rebel,’ were treated with colchicine. While shoot regeneration was severely repressed in ‘Emerald’ and ‘Rebel,’ shoot production from the V. fuscatum clone was not compromised at either 500 µM or 5000 µM colchicine concentrations. Due to the high number of shoots produced in vitro via the V. fuscatum clone shoots of this clone that had an enlarged stem diameter in vitro were subjected to flow cytometer analysis to screen for induced polyploidy. Sixteen synthetic tetraploid V. fuscatum, one synthetic octoploid ‘Emerald,’ and three synthetic octoploid ‘Rebel’ were identified. Growth rates of the polyploid-induced mutants were reduced compared to their respective wildtype controls. The leaf width and length of synthetic tetraploid V. fuscatum and synthetic octoploid ‘Emerald’ was increased compared to the wildtypes, whereas the leaf width and length of synthetic octoploid ‘Rebel’ were reduced compared to the wildtype controls. Significant increases in stem thickness and stomata guard cell length were found in the polyploidy-induced mutant lines compared to the wildtypes. In the meantime, stomata density was reduced in the mutant lines. These morphological changes may improve drought tolerance and photosynthesis in these mutant lines. Synthetic tetraploid V. fuscatum can be used for interspecific hybridization with highbush blueberries to expand the genetic base of cultivated blueberries. Full article

(1) Background: Polyploid fish are highly important in increasing fish production, improving fish quality, and breeding new varieties. The loach (Misgurnus anguillicaudatus), as a naturally polyploid fish, serves as an ideal biological model for investigating the mechanisms of chromosome doubling; (2) Methods: In this study, tetraploidization in diploid loach was induced by heat shock treatment, and, for the first time, the role of the key cell cycle gene cdk1 (cyclin-dependent kinase 1) in chromosome doubling was investigated; (3) Results: The experimental results show that when eggs are fertilized for 20 min and then subjected to a 4 min heat shock treatment at 39–40 °C, this represents the optimal induction condition, resulting in a tetraploid rate of 44%. Meanwhile, the results of the cdk1 knockout model (2n cdk1^−/−) constructed using CRISPR/Cas9 showed that the absence of cdk1 significantly increased the chromosome doubling efficiency of the loach. The qPCR analysis revealed that knockout of cdk1 significantly upregulated cyclin genes (ccnb3,ccnc, and ccne1), while inhibiting expression of the separase gene espl1 (p < 0.05); (4) Conclusions: During chromosome doubling in diploid loaches induced by heat shock, knocking out the cdk1 gene can increase the tetraploid induction rate. This effect may occur through downregulation of the espl1 gene. This study offers novel insights into optimizing the induced breeding technology of polyploid fish and deciphering its molecular mechanism, while highlighting the potential application of integrating gene editing with physical induction. Full article

Potato (Solanum tuberosum L.) crop yields may be reduced by nitrogen deficiency stress tolerance. An evaluation of 144 tetraploid potato genotypes was carried out during two consecutive seasons (2019 and 2020), with the objective of characterizing their variability in key physiological and agronomic parameters. Physiological parameters included chlorophyll content and fluorescence, stomatal conductance, NDVI, leaf area, and perimeter, while agronomic characteristics such as yield, tuber fresh weight, tuber number, starch content, dry matter, and reducing sugars were evaluated. To genotype the population, the GGP V3 Potato array was used, generating 18,259 high-quality SNP markers. Marker–trait association analysis was conducted using the GWASpoly package in R, applying Q + K linear mixed models to enhance precision. This methodology enabled the identification of 18 SNP markers that exhibited statistically significant associations with the traits analyzed in both trials and periods, relating them to genes whose functional implication has already been described. Genetic loci associated with chlorophyll content and tuber number were detected across non-stress and stress treatments, while markers linked to leaf area and leaf perimeter were identified specifically under nitrogen deficiency stress. The genomic distribution of these markers revealed that genetic markers or single-nucleotide polymorphisms (SNPs) correlated with phenotypic traits under non-stress conditions were predominantly located on chromosome 11, whereas SNPs linked to stress responses were mainly identified on chromosomes 2 and 3. These findings contribute to understanding the genetic mechanisms underlying potato tolerance to nitrogen deficiency stress, offering valuable insights for the development of future marker-assisted selection programs aimed at improving nitrogen use efficiency and stress resilience in potato breeding. Full article

Peanut (Arachis hypogaea L.) is a globally important oilseed cash crop, yet its limited genetic diversity and unique reproductive biology present persistent challenges for conventional crossbreeding. Traditional breeding approaches are often time-consuming and inadequate, mitigating the pace of cultivar development. Essential for double fertilization and programmed cell death (PCD), DUF679 membrane proteins (DMPs) represent a membrane protein family unique to plants. In the present study, a comprehensive analysis of the DMP gene family in peanuts was conducted, which included the identification of 21 family members. Based on phylogenetic analysis, these genes were segregated into five distinct clades (I–V), with AhDMP8A, AhDMP8B, AhDMP9A, and AhDMP9B in clade IV exhibiting high homology with known haploid induction genes. These four candidates also displayed significantly elevated expression in floral tissues compared to other organs, supporting their candidacy for haploid induction in peanuts. Subcellular localization prediction, confirmed through co-localization assays, demonstrated that AhDMPs primarily localize to the plasma membrane, consistent with their proposed roles in the reproductive signaling process. Furthermore, chromosomal mapping and synteny analyses revealed that the expansion of the AhDMP gene family is largely driven by whole-genome duplication (WGD) and segmental duplication events, reflecting the evolutionary dynamics of the tetraploid peanut genome. Collectively, these findings establish a foundational understanding of the AhDMP gene family and highlight promising targets for future applications in haploid induction-based breeding strategies in peanuts. Full article

Polyploidy in plants can enhance stress resistance and secondary metabolite production, offering potential benefits for Clausena lansium (L.) Skeel, a medicinally valuable species. However, systematic studies of polyploidy-induced morphological, anatomical, and metabolic changes in this species are lacking. This study aimed to induce and characterize polyploid C. lansium lines, assess ploidy-dependent variations, and evaluate their impact on bioactive metabolite accumulation. Three cultivars were hybridized, treated with colchicine, and bred, yielding 13 stable polyploid lines confirmed by flow cytometry and chromosome counting. The polyploids exhibited distinct traits, including larger pollen grains, altered leaf margins, increased leaflet numbers, enlarged guard cells with reduced stomatal density, and thicker leaf tissues. Metabolomic analysis revealed that tetraploids accumulated significantly higher levels of flavonoids, alkaloids, and phenolic acids compared to diploids, while triploids showed moderate increases. These findings demonstrate that polyploidization, particularly tetraploidy, enhances C. lansium’s medicinal potential by boosting pharmacologically active compounds. The study expands germplasm resources and supports the development of high-quality cultivars for pharmaceutical applications. Full article

Quinoa (Chenopodium quinoa Willd) is a tetraploid crop that has provided vital subsistence, nutrition, and medicine for Andean indigenous cultures. In recent years, quinoa has gained global importance all over the world. However, variations in fertility have been frequently observed during the flower development of quinoa, severely affecting quinoa production. To comprehend the fundamental causes of fertility variation in quinoa, this research examined hormonal metabolism and gene expression across three ecotypes: normal fertility (F), absent stamens (S1), and abnormal stamens (S3). S1 and S3 presented absent and abnormal stamens, respectively, compared with F. Phytohormone profiling yielded 60 metabolites and revealed the clear separation between different ecotypes at different developmental stages according to principal component analysis (PCA). The results of transcriptomics showed more DEGs (differentially expressed genes) identified between F and S1 ecotypes (8002 and 10,716 for earlier and later stages, respectively) than F vs. S3 (4500 and 9882 for earlier and later stages, respectively) and S1 vs. S3 (4203 and 5052 for earlier and later stages, respectively). Zeatin biosynthesis and hormone signal transduction pathways were enriched among 19 KEGG (Kyoto Encyclopedia of Genes and Genomes) terms, indicating their potential roles in quinoa flower fertility regulation. The correlation-based network presented the associations between selected hormones and genes, possibly regulating fertile ecotypes. Furthermore, we explored the expression of flower development-related genes in three ecotypes using RT-PCR, showing the higher expressions of AP1, AP3, and FLS in sterile ecotypes than fertile ecotypes at both stages. These findings reveal new insights into the hormonal and genetic regulations of floral fertility in quinoa, which may have consequences for developing high-yielding cultivars. Full article

Polyploidy plays a significant role in loquat breeding, particularly in triploid breeding for seedless fruit production. Currently, loquat polyploid breeding primarily relies on natural seedling selection and sexual hybridization approaches. In this study, unfertilized ovules from four loquat varieties were in vitro cultured. Gynogenesis and embryoid regeneration were achieved in ‘Xingning 1’ and ‘Huabai 1’, with ‘Xingning 1’ demonstrating the highest gynogenesis efficiency (21.63%). Flow cytometry and chromosome counting revealed that the obtained embryoid lines included haploid, diploid, tetraploid, hexaploid, and chimeric ploidy types. Further characterization of ‘Xingning 1’-derived embryoid lines through SSR markers and whole-genome resequencing confirmed that the haploid, diploid, tetraploid, and hexaploidy embryoid originated from haploid–somatic chimeras, diploid, doubled diploid and tripled diploid, respectively. Metabolic analysis showed a positive correlation between ploidy level and the content of both soluble sugars and organic acids. This study explored a novel platform for polyploid induction in loquat and may provide methodological insights for improvement of other perennial fruit trees. Full article

Modern wheat breeding has largely emphasized aboveground traits, often at the expense of belowground characteristics such as root biomass, architecture, and beneficial microbial associations. This has narrowed genetic diversity, impacting traits essential for stress resilience and efficient nutrient and water acquisition—factors expected to become increasingly critical under climate change. In this study, we evaluated 36 primary synthetic (PS) hexaploid wheat lines developed by crossing Aegilops tauschii with the durum wheat cultivar Langdon (LNG) and compared them with LNG and the hexaploid variety Norin 61 (N61). We observed significant variation in root length, biomass, and associations with fungal endophytes, including beneficial Arbuscular Mycorrhizal Fungi (AMF) and Serendipita indica, and pathogenic Alternaria sp. Clustering analysis based on these traits identified three distinct PS groups: (1) lines with greater root length and biomass, high AMF and S. indica colonization, and low Alternaria infection; (2) lines with intermediate traits; and (3) lines with reduced root traits and high Alternaria susceptibility. Notably, these phenotypic patterns corresponded closely with the soil classification of the Ae. tauschii progenitors’ origin, such as Cambisols (supportive of root growth), and Gleysols and Calcisols (restrictive of root growth). This highlights the soil microenvironment as a key determinant of belowground trait expression. By comparing PS lines with domesticated tetraploid and hexaploid wheat, we identified and selected PS lines derived from diverse Ae. tauschii with enhanced root traits. Our study emphasizes the potential of wild D-genome diversity to restore critical root traits for breeding resilient wheat. Full article