Search Results (1,919)

Pecan (Carya illinoinensis [Wangenh]. K. Koch) germplasm resources are abundant, yet the characteristics of each cultivar at the seedling stage remain insufficiently understood. This study systematically evaluated the growth parameters, photosynthetic traits, and anatomical structures of one-year-old grafted seedlings from five pecan cultivars: “Pawnee”, “Mandan”, “Nacono”, “Caddo”, and “Creek”. Principal component analysis (PCA) was employed to comprehensively assess 56 indicators. The results indicated that, in terms of vegetative growth, leaf area and biomass of “Nacono” and “Creek” were significantly greater than those of “Pawnee” (p < 0.05). “Mandan” ranked second. Additionally, the seedling quality index of “Creek” was markedly superior to all other cultivars (p < 0.05). Anatomically, “Pawnee” exhibited greater leaf thickness, more highly differentiated palisade tissue, and the development of the main vein. By contrast, “Mandan” displayed larger branch radius, cortex thickness, and pith radius, accompanied by finer vessels and large but sparsely distributed stomata (p < 0.05). Regarding photosynthetic performance, “Mandan” accumulated the highest concentrations of photosynthetic pigments and achieved the greatest photosynthetic efficiency, significantly outperforming the remaining cultivars (p < 0.05). The PCA-based comprehensive evaluation revealed that “Mandan” outperformed the other cultivars in seedling growth, making it the most suitable for promotion, followed by “Creek”, “Nacono”, “Caddo”, and “Pawnee”. This research offers a theoretical foundation for the breeding, promotion, and application of superior pecan cultivars. Full article

Polystyrene microplastic (MP) and its co-existing contaminants may exert different toxic effects on its surrounding aquatic organisms. In order to detect the intestinal harmful responses, tilapia were subjected to exposure with 75 nm of MPs, 100 ng·L⁻¹ of sulfamethoxazole (SMZ), 5 ng·L⁻¹ of BDE153, and combinations thereof over periods of 2, 4, and 8 days. Enzymatic assays, transcriptomics, proteomics, and metabolomics were employed to evaluate intestinal histopathological effects. Results showed that significant reductions were observed in ATP, ROS, SOD, EROD, lipid metabolism-related enzymes, pro-inflammatory cytokines (TNFα and IL-1β), and apoptosis marker caspase 3 across all groups at day 8. Histological evaluation revealed diminished goblet cell density, with distinct vacuole formation in the BDE153+MPs group. KEGG pathway analysis highlighted disruptions in endocytosis, MAPK signaling, phagosome formation, and actin cytoskeleton regulation. Proteomic findings indicated notable enrichment in endocytosis (decreased sorting nexin-2; increased Si:dkey-13a21.4), MAPK/PPAR signaling, protein processing in the endoplasmic reticulum (Sec61 subunit gamma), and cytoskeletal modulation (reduced fibronectin; elevated activation peptide fragment 1), with or without SMZ and BDE153. Metabolomic profiling showed significant alterations in ABC transporters, aminoacyl-tRNA biosynthesis, protein digestion and absorption, and linoleic acid metabolism. In summary, these findings suggest that BDE153 and MPs synergistically exacerbate intestinal damage and gene/protein expression over time, while SMZ appears to exert an antagonistic, mitigating effect. Full article

Sea urchin aquaculture has experienced remarkable growth in recent years. However, this growth has been accompanied by increased disease prevalence. Notably, spotting disease has particularly severe impacts. In this study, we isolated the pathogen HZ-3-2 from 10 sea urchins with spotting disease, and it was identified as Vibrio splendidus through morphological observations, 16S rDNA sequencing, and whole-genome sequencing. Subsequently, experimental infection confirmed that V. splendidus (HZ-3-2) is the causative agent of spotting disease in this outbreak. The drug sensitivity confirmed the presence of drug resistance genes, such as CPR, QNRS5, and rsmA, which were identified in the genome. The tests indicated that V. splendidus was sensitive to various antibiotics, including fluoroquinolones and florfenicol. Finally, we used the transcriptome to explore the molecular response of the diseased sea urchin. Compared to the control group, a group of sea urchins immersed in a pathogen suspension with a concentration of 10⁷ CFU/mL (group M) resulted in 439 annotated differentially expressed genes. KEGG pathway analysis indicated significant activation of cholesterol metabolism and starch and sucrose metabolism in the S. intermedius. This study highlights the genes NPC1, AMY2A, and MGAM as critical regulators of energy metabolism, and cholesterol synthesis in infected sea urchins. These findings confirm V. splendidus as the bacterium responsible for spotting disease and provide valuable insights into the intestinal molecular response of S. intermedius to infection. Full article

Buckwheat (Fagopyrum tataricum) is native to Yunnan, China, and as a miscellaneous grain crop with high nutritional value, it has received increased attention from farmers and enterprises in recent years. In June 2024, we observed severe anthracnose in the buckwheat cultivation area in Malu Township and Jiache Township, Huize County, Qujing City, Yunnan Province, China. In this study, six isolates (SM01–SM06) of anthracnose with similar morphology were obtained using the tissue isolation method, which was due to the fact that this disease is highly pathogenic to buckwheat. The strain SM02 was selected as a representative isolate for biological characterization and molecular phylogenetic analysis, and a phylogenetic tree was constructed based on the ACT, CHS, and ITS genes to determine its taxonomic status. The selected SM02 isolate was further identified as Colletotrichum kahawae. Biological characterization showed that the representative strain SM02 exhibited optimal growth for in vitro cultivation under a photoperiod, temperature, pH, carbon source, and nitrogen source of 12L:12D, 25 °C, pH 7.0, glucose, and beef extract, respectively. Host range testing demonstrated that C. kahawae might infect important field crops, including maize, wheat, oats, and potatoes. In conclusion, C. kahawae causes buckwheat anthracnose in China, which might hinder the production of buckwheat. This study provides insight into anthracnose disease in buckwheat and provides a basis for further investigations to assess and implement effective disease management strategies. Full article

Cowpea (Vigna unguiculata L. Walp.) is a species with superior tolerance to drought stress compared to other legumes. It is a promising crop with increasing importance in the face of global climate changes. Local forms, well adapted to particular agro-climatic conditions, are useful germplasm resources. Five Bulgarian cowpea landraces, which had displayed differences in osmotic stress tolerance at the germination stage, were subjected to severe stress (15% PEG 6000 in Hoagland nutrient media) during 16 days at the vegetative growth stage (plants with expanded trifoliate leaves). All local forms responded to the imposed stress by biomass and leaf area diminution, a slight increase in leaf water deficit and electrolyte leakage, proline accumulation in roots and leaves, and an increase in root starch and leaf phenol content. Roots presented more pronounced metabolic changes than leaves, including increased total antioxidant activity, phenolic and carbohydrate content, and proline accumulation. Under osmotic stress, tight control of oxidative stress and concerted upregulation of superoxide dismutase, catalase, glutathione transferase, and peroxidase activities in leaves were registered along with changes in certain specific isoforms, while glutathione reductase activity diminished. Antioxidant enzyme activities had different changes in stressed roots, compared to leaves, and among genotypes. The accession most sensitive to osmotic stress at germination presented more symptoms of oxidative stress at the vegetative growth stage. Full article

Nitrogen is an essential nutrient for the growth and development of maize (Zea mays L.), and soil nitrogen deficiency is an important factor limiting maize yield. Although excessive application of nitrogen fertilizer can increase yield, it can also cause environmental problems. Therefore, screening low-nitrogen-tolerant (LNT) germplasm resources and analyzing their genetic mechanisms are of great significance for the development of efficient and environmentally friendly agriculture. In this study, 201 maize inbred lines were used as materials. Two levels of low nitrogen (LN) (0.05 mmol/L, N1) and normal nitrogen (4 mmol/L, N2) were set up. Phenotypic indicators such as seedling length, root length and biomass were measured, and they were classified into LNT type (18 samples), nitrogen-sensitive (NS) type (27 samples) and intermediate type (156 samples). A total of 47 significant SNP loci were detected through a genome-wide association study (GWAS), and 36 candidate genes were predicted. Transcriptome sequencing (RNA-seq) analysis revealed that the differentially expressed genes (753 upregulated and 620 downregulated) in LNT materials under low nitrogen stress (LNS) were significantly fewer than those in NS materials (2436 upregulated and 2228 downregulated). Further analysis using WGCNA identified a total of eight co-expression modules. Among them, the red module was significantly correlated with root length and underground fresh weight under LN conditions (r = 0.75), and three key genes for stress response (Zm00001d005264, Zm00001d053931, Zm00001d044292) were screened out. Combined with GWAS, RNA-seq and qRT-PCR verification, eight candidate genes closely related to LNT at the seedling stage of maize were finally determined, involving biological processes such as stress response, nitrogen metabolism and substance formation. This study initially revealed the molecular mechanism of maize tolerance to LN through multi-omics analysis, providing a theoretical basis and genetic resources for breeding new nitrogen-efficient maize varieties. 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

The GRF (Growth-Regulating Factor) gene family has indispensable regulatory functions in the morphological and physiological development of plants. Nonetheless, comprehensive investigations of GRF gene family members and their functional roles in Cymbidium goeringii, Cymbidium ensifolium, and Cymbidium sinense are still lacking. Therefore, the GRF gene family members in three Cymbidium species were systematically identified, and their expression profiles and potential biological functions were comprehensively evaluated in the study. The results provided evidence that eleven, eleven, and nine GRF genes were identified in C. goeringii, C. ensifolium, and C. sinense, respectively. These genes encode proteins considered as 153–584 amino acids and have been postulated to be located in the cell nucleus. The promoter contains cis-acting elements associated with hormone response regulation, tissue-specific expression, modulation of organismal growth and development, and environmental signal response. The analyses of gene architecture and motif composition demonstrated that introns and motifs within each evolutionary branch are highly similar, whereas significant differences exist between evolutionary branches. The results of chromosome localization and collinearity analysis showed that only a pair of segmental duplication genes was identified in C. goeringii. Moreover, transcriptome data and qRT-PCR results indicated that GRF genes are involved in various organs of C. goeringii. In conclusion, these findings may establish a foundation for theoretical inquiry into the future functional analysis of GRF genes in orchids. Full article

In this study, we aimed to explore the biological characteristics and quality of crayfish (Procambarus clarkii) reared in different modes and fill in the research gap regarding assessments of Procambarus clarkii quality in the cold regions of China. To achieve this, typical rice–crayfish coculture (RCCC) and pond culture (PC) modes were established in Northeast China to evaluate the chelae proportion (CP), hepatosomatic index (HSI), abdominal meat yield (MY), proximate composition, fatty acids, free amino acids, and mineral elements of Procambarus clarkii. Extremely significantly higher CP (32.50%) but lower HSI (6.22%) and MY (9.54%) were observed in P. clarkii reared in the RCCC compared with those reared in the PC. The RCCC contained higher levels of total lipids, ∑MUFA, ∑EFA, h/H, ∑EFAA, ∑FAA, ∑TUV, ∑TBV, and ∑TME but lower levels of crude protein, ∑SFA, DHA + EPA, DHA/EPA, AI, and ∑TSV in the hepatopancreas. In addition, the RCCC had higher levels of ∑SFA, ∑EFA, AI, TI, ∑EFAA, ∑FAA, ∑TUV, and ∑TBV but lower levels of ∑HUFA, ∑n-6 PUFA, DHA/EPA, h/H, ∑TSV, and ∑TME in muscle. In summary, the culture modes of P. clarkii reared in the cold regions of China have an influence on the biological characteristics and quality of this species. Full article

To explore the phenotypic diversity of jujube germplasm resources and identify superior genotypes, this study systematically evaluated 150 jujube accessions. Multiple organ-related traits—including branches, thorns, bearing shoots, leaves, flowers, and fruits—were investigated. A comprehensive, multidimensional analysis was conducted to assess phenotypic variation and diversity. The results provide valuable insights for germplasm conservation and the selection of elite jujube varieties. The results showed that the variation coefficient of 18 quantitative traits ranged from 5.07% to 21.43%; the variation coefficient of fruit quality traits ranged from 4.25% to 13.48%; and the results of the cluster analysis showed that the germplasm resources were classified into three categories according to the quantitative traits and four categories according to the fruit quality traits. Principal component analysis extracted six significant components for fruit quality traits, accounting for 86.88% of the total variance. Based on the comprehensive evaluation of factor analysis, Sanlengzao, Linyilajiaozao, Zan 2, Jinmanguo, and Jing 39 performed well and ranked high in the comprehensive ranking, which can be used as an important reference for the evaluation of jujube germplasm resources and the selection and breeding of good varieties. Full article

Selenium can be absorbed and utilized by plants, influencing their growth by altering their physiological metabolism. In this study, based on plant physiology methods, compared to the CK treatment, the height and leaf length of oat seedlings under the T0.02 (0.02 g/kg Na₂SeO₃) treatment significantly increased by 18.36% and 15.81%, respectively (p < 0.05). Under the T0.1 (0.1 g/kg Na₂SeO₃) treatment, the levels of malondialdehyde (MDA), proline, soluble sugar content, and peroxidase (POD) activity significantly increased (p < 0.05). However, the seedling height and leaf length under the T0.1 treatment significantly decreased by 33.24% and 23.25%, respectively. Additionally, the contents of chlorophyll a, chlorophyll b, and carotenoids, as well as ascorbate peroxidase (APX) activity and the superoxide anion radical generation rate (O₂⁻) significantly decreased (p < 0.05). The total selenium, organic selenium, and inorganic selenium contents, as measured by the atomic fluorescence spectroscopy method, were also increased in oat seedling roots and leaves under T0.1 treatment (p < 0.05). Selenium had a high coefficient of mobility from root to leaf of 6.01 under T0.02 and 4.65 under T0.1 treatment, and from soil to leaf of 4.98 under T0.02 and 4.55 under T0.1 treatment. Through untargeted metabolomics, six differential phenylpropanoid compounds and 18 differential flavonoid compounds were found in oat seedlings. Based on transcriptomic analysis of oat seedlings, 29 DEGs associated with phenylpropanoid metabolism and 13 DEGs related to flavonoid biosynthesis were identified. Over 60% of the genes (25/42) in the phenylpropanoid and flavonoid biosynthesis pathway were associated with the accumulation of about 74% (20/27) of the compounds in oat leaves. Based on transcriptomic and metabolomics analysis, there were nine major genes (including PAL1, PAL4, CHS2, PAL7, POD3, PAL6, CCR1, CCR4, POD4) modulating the metabolism of phenylpropanoid and flavonoid biosynthesis pathway. This study offers novel insights and genetic resources for exploring the mechanisms underlying plant responses to selenium treatment, thereby further enhancing selenium tolerance in plants. Full article

Nile tilapia (Oreochromis niloticus) is a key species due to its rapid growth, high nutritional value, and adaptability to diverse environments. However, changes in water salinity pose significant challenges to tilapia farming. Elucidating the adaptive strategies of tilapia to fluctuating salinity environments is crucial for improving aquaculture efficiency. This study investigated the transcriptional signature of growth-hormone-releasing hormone, somatostatin, growth hormone, and insulin-like growth factor (grhr-sst-gh-igf) axis in Nile tilapia under different salinity conditions (0 g/L, 16 g/L, and 30 g/L). The results showed that in brackish or seawater, Nile tilapia rapidly upregulate brain igfbp5 paralogues and their regulators (sst5, sstr2) to sustain growth-active IGF-1 signaling, while in the liver and gut, they downregulate sstr2b, igfbp1/7, and ghrh to reallocate energy toward osmoregulation. Physiological regulation, such as the use of ligand analogs, or genetic enhancement targeting these genes might hold promise for improving salt acclimation, which would enable profitable farming in brackish or coastal ponds and offer a simple tool for more resilient and efficient tilapia production. Full article

Drought stress is one of the key abiotic stress factors limiting the growth and development, yield formation, and improvement in the quality of jackfruit (Artocarpus heterophyllus). However, systematic evaluations of drought tolerance in jackfruit germplasm resources remain limited. In this study, six jackfruit cultivars were used as materials. By systematically comparing 26 indicators, including leaf structural characteristics, chlorophyll concentration, and photosynthetic parameters, the primary evaluation indicators for jackfruit drought tolerance were identified, and clear microscopic structural images of leaves from different jackfruit cultivars were obtained. In this study, significant differences were observed among different jackfruit germplasm resources in terms of leaf structure, chlorophyll concentration, and photosynthetic characteristics. Comprehensive analysis identified A. ‘Changyou’ as the jackfruit cultivar with the highest drought tolerance score and A. ‘Siji’ as the variety with the lowest drought tolerance score. By establishing a systematic evaluation system for jackfruit drought tolerance, it was found that jackfruit cultivars with high drought tolerance had significantly thicker palisade parenchyma than other cultivars, a rougher leaf epidermis, and more densely distributed stomata on the leaves, while their chlorophyll concentration was significantly lower than that of cultivars with lower drought tolerance scores. Jackfruit cultivars with the lowest drought resistance scores had significantly lower net photosynthetic rates, transpiration rates, stomatal conductance, and light saturation points than other cultivars. This study’s results established a drought resistance evaluation system for jackfruit germplasm resources, providing theoretical support for the selection and breeding of high-drought-resistant superior jackfruit cultivars. Full article

Germplasm resources embody the genetic diversity of plants and form the foundation for breeding and the ongoing improvement of elite cultivars. The establishment of germplasm banks, along with their systematic evaluation, constitutes a critical step toward the conservation, sustainable use, and innovative utilization of these resources. Liriodendron, a rare and endangered tree genus with species distributed in both East Asia and North America, holds considerable ecological, ornamental, and economic significance. However, a standardized evaluation system for Liriodendron germplasm remains unavailable. In this study, 297 Liriodendron germplasm accessions were comprehensively evaluated using 34 phenotypic traits and whole-genome resequencing data. Substantial variation was observed in most phenotypic traits, with significant correlations identified among several characteristics. Cluster analysis based on phenotypic data grouped the accessions into three distinct clusters, each exhibiting unique distribution patterns. This classification was further supported by principal component analysis (PCA), which effectively captured the underlying variation among accessions. These phenotypic groupings demonstrated high consistency with subsequent population structure analysis based on SNP markers (K = 3). Notably, several key traits exhibited significant divergence (p < 0.05) among distinct genetic clusters, thereby validating the coordinated association between phenotypic variation and molecular markers. Genetic diversity and population structure were assessed using 4204 high-quality single-nucleotide polymorphism (SNP) markers obtained through stringent filtering. The results indicated that the Liriodendron sino-americanum displayed the highest genetic diversity, with an expected heterozygosity (He) of 0.18 and a polymorphic information content (PIC) of 0.14. In addition, both hierarchical clustering and PCA revealed clear population differentiation among the accessions. Association analysis between three phenotypic traits (DBH, annual height increment, and branch number) and SNPs identified 25 highly significant SNP loci (p < 0.01). Of particular interest, the branch number-associated locus SNP_17_69375264 (p = 1.03 × 10⁻⁵) demonstrated the strongest association, highlighting distinct genetic regulation patterns among different growth traits. A minimal set of 13 core SNP markers was subsequently used to construct unique DNA fingerprints for all 297 accessions. In conclusion, this study systematically characterized phenotypic traits in Liriodendron, identified high-quality and core SNPs, and established correlations between key phenotypic and molecular markers. These achievements enabled differential analysis and genetic diversity assessment of Liriodendron germplasm, along with the construction of DNA fingerprint profiles. The results provide crucial theoretical basis and technical support for germplasm conservation, accurate identification, and utilization of Liriodendron resources, while offering significant practical value for variety selection, reproduction and commercial applications of this species. Full article

Capsicum is one of the most economically significant vegetable crops worldwide, owing to its high content of bioactive compounds with nutritional, pharmacological, and industrial relevance. However, research has focused on C. annuum, often disregarding local diversity and secondary gene pools, which may contain hidden variation for quality traits. Therefore, this study evaluated the genetic and phenotypic diversity of 283 accessions from the Colombian germplasm collection in the agrobiodiversity hotspot of northwest South America, representing all five domesticated species of the genus. A total of 18 morphological, physicochemical, and biochemical fruit traits were assessed, including texture, color, capsaicinoid, and carotenoid content. The phenotypic data were integrated with genomic information obtained through genotyping-by-sequencing (GBS) using the C. annuum reference genome and a multispecies pangenome. Fixed-and-Random-Model-Circulating-Probability-Unification (FarmCPU) and Bayesian-information-and-Linkage-disequilibrium-Iteratively-Nested-Keyway (BLINK) genome-wide association studies (GWAS) were performed on both alignments, respectively, leading to the identification of complex polygenic architectures with 144 and 150 single nucleotide polymorphisms (SNPs) significantly associated with key fruit quality traits. Candidate genes involved in capsaicinoid biosynthesis were identified within associated genomic regions, terpenoid and sterol pathways, and cell wall modifiers. These findings highlight the potential of integrating pangenomic resources with multi-omics approaches to accelerate Capsicum improvement programs and facilitate the development of cultivars with enhanced quality traits and increased agro-industrial value. Full article