Effects of high NaHCO3 alkalinity on growth, tissue structure, digestive enzyme activity, and gut microflora of grass carp juvenile.

With the gradual decrease in freshwater resources, the available space for freshwater aquaculture is diminishing. As a result, saline-alkaline water aquaculture has emerged as a crucial method to fulfill the increasing demand. This study investigates the impact of alkaline water on the growth performance, tissues (gill, liver, and kidney), digestive enzyme activity, and intestinal microbiology in grass carp (Ctenopharyngodon idella). The aquarium conditions were set with sodium bicarbonate (18 mmol/L (LAW), 32 mmol/L (HAW)) to simulate the alkaline water environment. A freshwater group was the control (FW). The experimental fish were cultured for 60 days. The findings revealed that NaHCO3 alkaline stress significantly reduced growth performance, caused alterations in the structural morphology of gill lamellae, liver, and kidney tissues, and led to decreased activity of intestinal trypsin and lipase amylase (P < 0.05). Analysis of 16S rRNA sequences demonstrated that alkalinity influenced the abundance of dominant bacterial phyla and genera. Proteobacteria showed a significant decrease under alkaline conditions, while Firmicutes exhibited a significant increase (P < 0.05). Furthermore, alkalinity conditions significantly reduced the abundance of bacteria involved in protein, amino acid, and carbohydrate metabolism, cell transport, cell decomposition, and environmental information processing. Conversely, the abundance of bacteria associated with lipid metabolism, energy metabolism, organic systems, and disease functional flora increased significantly under alkalinity conditions (P < 0.05). In conclusion, this comprehensive study indicates that alkalinity stress adversely affected the growth performance of juvenile grass carp, likely due to tissue damage, reduced activity of intestinal digestive enzymes, and alterations in intestinal microorganisms.

Land carbon metabolism in Xiamen-Zhangzhou-Quanzhou region based on ecological network analysis.

Discovering the underlying mechanisms between carbon metabolism and carbon balance of human-natural system is of important theoretical and practical significance for reducing regional carbon emissions and promoting low-carbon development. Taking Xiamen-Zhangzhou-Quanzhou region from 2000 to 2020 as an example, we constructed the framework of spatial network model of land carbon metabolism based on carbon flow, and inquired into the spatial and temporal heterogeneity in the carbon metabolic structure, function and ecological relationships by using the ecological network analysis. The results showed that the dominant negative carbon transitions related with land use changes came from the conversion of cultivated land to industrial and transportation land, and that the high value areas of negative carbon flow were mainly distributed in the areas with relatively developed industries in the middle and east parts of Xiamen-Zhangzhou-Quanzhou region. Competition relationships were the dominant type and the spatial expansion was obvious, which led to the decreases of the integral ecological utility index and affected the regional carbon metabolic balance. The ecological network hierarchy of driving weight changed from a pyramid structure to a relatively more regular structure, with the producer contributing the most. The ecological network hie-rarchy of pull weight changed from a pyramid structure to an inverted pyramid structure, mainly due to the excessive increase of industrial and transportation land weights. Low-carbon development should focus on the sources of negative carbon transitions caused by land use conversion and its comprehensive impacts on carbon metabolic balance, to formulate differentiated low-carbon land use patterns and carbon emission reduction policies.

Effects of hypoxia and reoxygenation on oxidative stress, histological structure, and apoptosis in a new hypoxia-tolerant variety of blunt snout bream (Megalobrama amblycephala).

A new hypoxia-tolerant variety of blunt snout bream was obtained by successive breeding of the wild population, which markedly improved hypoxia tolerance. In this study, the hypoxia-tolerant variety was exposed to hypoxia (2.0 mg O2·L-1) for 4, 7 days. The contents of blood biochemical indicators including the number of red blood cells (RBC), total cholesterol (T-CHO), total protein (TP), triglyceride (TG), glucose (GLU), and lactic acid (LD) increased significantly (P < 0.05) under hypoxia. The glycogen content in the liver and muscle decreased significantly (P < 0.05) and the LD content in the brain, muscle and liver increased significantly (P < 0.05) under hypoxia. The levels of oxidative stress-related indicators i.e., superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), catalase (CAT), and total antioxidant capacity (T-AOC) also changed significantly (P < 0.05) in the heart, liver, and intestine of the new variety under hypoxia. Additionally, hypoxia has caused injuries to the heart, liver, and intestine, but it shows amazing repair ability during reoxygenation. The apoptotic cells and apoptosis rate in the heart, liver, and intestine increased under hypoxia. Under hypoxia, the expression of the B-cell lymphomas 2 (Bcl-2) gene in the heart, liver, and intestine was significantly (P < 0.05) down-regulated, while the expression of the BCL2-associated agonist of cell death (Bad) gene was significantly (P < 0.05) up-regulated. These results are of great significance for enriching the basic data of blunt snout bream new variety in response to hypoxia and promoting the healthy development of its culture industry.

Gill remodeling increases the respiratory surface area of grass carp (Ctenopharyngodon idella) under hypoxic stress.

Seasonal changes, diurnal variations, and eutrophication result in periodic hypoxia in fish habitats, thus affecting the success of commercial aquaculture. In this study, the grass carp (Ctenopharyngodon idella) presented moderate hypoxia tolerance; they showed a medium critical oxygen tension during the loss of equilibrium. In response to 7 d of hypoxic exposure, the erythrocyte count and hemoglobin (Hb) concentration significantly increased (p < 0.01). To cope with the hypoxic environment, the grass carp underwent gill remodeling marked by reduction in the interlamellar cell mass (ILCM) and an increase in respiratory surface area. The gill remodeling under hypoxia was enabled by apoptosis induction. Although apoptotic signals were not found on ILCM cells, transferase dUTP nick end labeling (TUNEL) assay results indicated that after 1 d of hypoxic exposure, the number of TUNEL-positive cells per lamella increased until 4 d and then began to decrease. Consistent with the results of the TUNEL assay, the mRNA expression of apoptosis-related genes, caspase-3, Bax, and Bcl-2, increased at 1, 4, and 7 d of the hypoxia treatment. In addition, gill remodeling significantly (p < 0.01) decreased the concentration of sodium and chloride ions in the fish serum. These findings provide evidence that grass carps increase their respiratory surface area through gill remodeling by apoptosis in the gill filaments to acclimate to a hypoxic environment. This study expands our understanding of the morphological and physiological changes in grass carp in response to a hypoxic environment; therefore, it could be useful for maintaining grass carp production.

[Spatial relationship between landscape ecological risk and ecosystem service value in Fujian Province, China during 1980-2020]. / 1980­2020å¹´ç¦å»ºçœæ™¯è§‚ç”Ÿæ€é£Žé™©ä¸Žç”Ÿæ€ç³»ç»ŸæœåŠ¡ä»·å€¼çš„ç©ºé—´å ³ç³».

Understanding the relationship between landscape ecological risk and ecosystem service value (ESV) is important for building an ecological security pattern and enhancing human well-being. Taking Fujian Province as the research area, based on the remote sensing monitoring data of land use in 1980, 2000, and 2020, we carried out a grid resampling size of 5 km × 5 km in the study area, quantitatively evaluated the landscape ecological risk and ESV, and analyzed the spatio-temporal variations. The spatial correlation between landscape ecological risk and ESV was investigated by using the bivariate spatial autocorrelation analysis and the spatial regression models. The results showed that the landscape ecological risk level in Fujian Province changed from medium level to low level, with the situation being improved. The landscape ecological risk level was generally higher in the east region and lower in the west region. ESV generally declined. The functional structure of each ecosystem was relatively stable. ESV spread from high to low with high value area as the core. There was a significant negative spatial correlation between landscape ecological risk and ESV. Landscape ecological risk had a negative effect on ecosystem total ser-vice value, with the strongest impact on the supply function.

Clinical characteristics and postoperative outcomes of systemic artery-to-pulmonary vessel fistula in hemoptysis patients.

OBJECTIVES: To investigate the clinical characteristics and outcomes on the success of bronchial arterial embolization (BAE) in patients with and without systemic artery-to-pulmonary vessel fistula (SA-PF) and to evaluate the feasibility of CTA in the assessment of SA-PF. METHODS: We retrospectively enrolled 420 consecutive patients that underwent BAE for hemoptysis control in our hospital from September 2011 to May 2019. The clinical characteristics, preprocedural CTA findings, BAE procedural findings, and follow-up outcomes were collected. Patients were divided into two groups according to DSA findings: patients with SA-PF and those without. RESULTS: A total of 184 (43.7%) patients presented with SA-PF. Pneumonia was less likely to be the concomitant condition in patients with SA-PF (p < 0.001). The mean number of culprit arteries per patient was significantly higher in patients with SA-PF compared to that in patients without SA-PF (p = 0.017). The SA-PF patients saw a greater probability of recurrence (HR: 2.782, 95% CI: 1.617-4.784, p < 0.001). SA-pulmonary venous fistula (SA-PVF) favored lower hemoptysis recurrence rate (HR: 0.199, 95%CI: 0.052-0.765, p = 0.019). SA-pulmonary artery fistula (SA-PAF) can be detected by optimized CTA protocol with a detection rate of 65.3% (49/75). CONCLUSIONS: The presence of SA-PF is an independent risk factor predicting early recurrence of hemoptysis after BAE. SA-PVF seems to be a protective factor for longer hemoptysis control compared to SA-PAF. Optimized preprocedural CTA is a reliable examination to identify SA-PAF. KEY POINTS: • The appearance of SA-PF is associated with a greater probability of early recurrent hemoptysis after bronchial artery embolization. • The presence of SA-PVF seems to be a protective factor for longer hemoptysis control after BAE compared to SA-PAF. • Optimized CTA protocol seems to be a promising auxiliary examination to detect SA-PAF.

Ecosystem service pattern of Fuzhou City based on ecosystem service bundles.

Based on InVEST model, recreational opportunity spectrum, factor analysis, cold and hot spot analysis, SOFM neural network, relief degree of land surface (RDLS) methods, we evalua-ted six kinds of ecosystem service in Fuzhou City and analyzed the trade-offs and synergies among them, with the aim to clarify the dominant services and the spatial pattern of service bundles in different topographical regions. The results showed substantial spatial heterogeneity in different ecosystem services of Fuzhou City. Water yield, carbon sequestration, habitat quality, and recreational opportunities were totally high, whereas the supply of agricultural products and soil and water conservation were low and substantial differences. The interaction between water yield and cultural servi-ces were synergies, but trade-offs occurred among regulating service, supporting service and agricultural products service. There were spatial aggregations for both trade-offs and synergies. Ecosystem service bundles could be divided into suburban recreation bundle, water conservation bundle, agricultural products bundle, urban life bundle, and forest ecological conservation bundle. The composition of service bundles clusters was different under different RDLS, with obvious spatial heterogeneity.

[Cytogenetic and molecular analysis of a case of Prader-Willi syndrome].

OBJECTIVE: To investigate the significance of cytogenetic and molecular genetic diagnosis of a special type of secondary sexual dysplasia and the applicability of various methods for its detection. METHODS: Using karyotype analysis, array comparative genomic hybridization (aCGH), multiplex ligation-dependent probe amplification (MLPA) and methylation-specific PCR (MS-PCR), we diagnosed and differentially diagnosed a case of secondary sexual dysplasia. RESULTS: Abnormalities were not found in the karyotype analysis or the SRY and AZF gene detection, nor chromosomal duplication and deletion in the initial SurePrint G3 Human CGH Array Kit8×60K.SurePrint G3 unrestricteda CGH ISCA v2,88×60K, however, identified a 68.9 kb deletion of chromosome 15 (hg19:25190737-25259677). MLPA revealed the deletion of exon 3 of the SNRPN gene. MS-PCR showed a significant decrease in the paternal fragment signals, but no difference in the maternal fragment signals between the sample from the patient and that from the control. CONCLUSIONS: The patient was confirmed with Prader-Willi syndrome by various methods of detection.

Draft genomes of female and male turbot Scophthalmus maximus.

Turbot (Scophthalmus maximus) is a commercially important flatfish species in aquaculture. It has a drastic sexual dimorphism, with females growing faster than males. In the present study, we sequenced and de novo assembled female and male turbot genomes. The assembled female genome was 568 Mb (scaffold N50, 6.2 Mb, BUSCO 97.4%), and the male genome was 584 Mb (scaffold N50, 5.9 Mb, BUSCO 96.6%). Using two genetic maps, we anchored female scaffolds representing 535 Mb onto 22 chromosomes. Annotation of the female anchored genome identified 87.8 Mb transposon elements and 20,134 genes. We identified 17,936 gene families, of which 369 gene families were flatfish specific. Phylogenetic analysis showed that the turbot, Japanese flounder and Chinese tongue sole form a clade that diverged from other teleosts approximately 78 Mya. This report of female and male turbot draft genomes and annotated genes provides a new resource for identifying sex determination genes, elucidating the evolution of adaptive traits in flatfish and developing genetic techniques to increase the sustainability of turbot aquaculture.

Genome-wide identification, characterization, and expression analysis of the TRAF gene family in Chinese tongue sole (Cynoglossus semilaevis).

Tumor necrosis factor (TNF) receptor-associated factors (TRAFs) play crucial roles as signaling mediators for the TNF receptor (TNFR) superfamily and the interleukin-1 receptor/Toll-like receptor (IL-1R/TLR) superfamily. TRAFs collectively play important roles in multiple biological processes and organismal immunity. However, systematic identification of the TRAF gene family in teleost fish has not yet been reported, and there is little available information about its roles in innate immunity in Chinese tongue sole (Cynoglossus semilaevis), an aquaculture fish of high economic value. In the present study, we identified and characterized seven TRAF genes, namely, CsTRAF2a, CsTRAF2b, CsTRAF3, CsTRAF4, CsTRAF5, CsTRAF6 and CsTRAF7, in Chinese tongue sole, and the complete ORFs of the CsTRAFs were cloned. Sequence analysis revealed various genomic structures of the CsTRAFs and showed that they contain typical conserved domains compared with mammalian TRAFs. Phylogenetic analysis indicated the evolutionary relationships of TRAF family members in teleost fish and revealed an absence of TRAF1 in most species and TRAF5 in some species of teleosts. Analysis of the gene structures and motifs showed the diversity and distribution of exon-intron structures and conserved motifs in Chinese tongue sole and several other teleost species. Real-time quantitative PCR was used to investigate the expression patterns of CsTRAF genes in tissues of healthy fish and in the gills, livers and spleens of fish after bacterial infection with Vibrio harveyi. The results indicate that only CsTRAF2a is relatively highly expressed in the brain and that the other CsTRAFs are highly expressed in immune-related tissues and may participate in the immune response after infection with pathogenic bacteria. Functional analysis of CsTRAF3, CsTRAF4 and CsTRAF6 revealed that only CsTRAF6 could strongly activate the NF-кB pathway after overexpression of CsTRAF3, CsTRAF4 and CsTRAF6 in HEK-293T cells. This systematic analysis provided valuable information about the diverse roles of TRAFs in the innate immune response to pathogenic bacterial infection in teleost fish and will contribute to the functional characterization of CsTRAF genes in further research.

Constructing a Risk Prediction Model for Lung Cancer Recurrence by Using Gene Function Clustering and Machine Learning.

OBJECTIVE: A significant proportion of patients with early non-small cell lung cancer (NSCLC) can be cured by surgery. The distant metastasis of tumors is the most common cause of treatment failure. Precisely predicting the likelihood that a patient develops distant metastatic risk will help identify patients who can further intervene, such as conventional adjuvant chemotherapy or experimental drugs. METHODS: Current molecular biology techniques enable the whole genome screening of differentially expressed genes, and rapid development of a large number of bioinformatics methods to improve prognosis. RESULTS: The genes associated with metastasis do not necessarily play a role in the pathogenesis of the disease, but rather reflect the activation of specific signal transduction pathways associated with enhanced migration and invasiveness. CONCLUSION: In this study, we discovered several genes related to lung cancer resistance and established a risk model to predict high-risk patients.

pik3r3b, a novel immune-related gene in Nile tilapia (Oreochromis niloticus): Identification, expression and analysis of antibacterial activity.

A full-length cDNA encoding phosphatidylinositol 3-kinase regulatory subunit gamma b gene in Nile tilapia (Oreochromis niloticus), termed as On-pik3r3b, was identified and characterized in this study. The sequence analysis demonstrated that the full-length cDNA of On-pik3r3b was 2018 bp, containing a 5' untranslated region (UTR) of 171 bp, an open reading frame (ORF) of 1422 bp and a 3' UTR of 425 bp. Its protein sequence displayed a high degree of identity with other fish. Using qPCR, the expression patterns of On-pik3r3b were investigated. In healthy Nile tilapia, the transcripts of On-pik3r3b were detected in all examined tissues, except the skin. Upon the stimulation with Streptococcus agalactiae, the On-pik3r3b expression level in liver, spleen, kidney and gill were significantly increased at 12 h after infection. The recombinant On-pik3r3b showed in vitro antibacterial activity, against S. agalactiae and E. coli. Our observation strongly indicates that On-pik3r3b is involved in the innate immune response in Nile tilapia.

Cloning, expression prolife, and immune characterization of a novel stat family member (stat5bl) in Chinese tongue sole (Cynoglossus semilaevis).

STAT plays important roles in innate immunity during JAK/STAT signaling pathway, and STAT5 is particularly focused due to the existence of duplicated forms in fish and mammal. In Chinese tongue sole, stat5bl was suggested to be a candidate related to Vibrio harveyi resistance based on previous QTL screening. In this study, the full length of stat5bl cDNA was cloned and its expression patterns were analyzed. stat5bl was predominantly expressed in immune tissues, where the highest level was observed in liver, followed by skin and gill. Time course expression patterns were examined in six tissues (liver, skin, gill, kidney, intestine, spleen) after V. harveyi infection. stat5bl could be up-regulated by V. harveyi infection in all tissues except liver, despite the timepoints of peak were different. In contrast, stat5bl was significantly downregulated in liver. To elucidate the role of stat5bl in liver, in vitro RNAi were performed using primary liver cell culture. Knockdown of stat5bl could regulate the expression of genes closely related to JAK/STAT pathway. This study would enlarge our understanding of stat5bl in fish immunity.

Cloning, characterization and functional analysis of dctn5 in immune response of Chinese tongue sole (Cynoglossus semilaevis).

In mammals, microtubule-dependent trafficking could participate the immune response, where the motor proteins are suggested to play an important role in this process, while the related study in fish was rare. In this study, dctn5, a subunit of dyactin complex for docking motor protein, was obtained by previous immune QTL screening. The full-length cDNAs of two dctn5 transcript variants were cloned and identified (named dctn5_tv1 and dctn5_tv2, respectively). Tissue distribution showed that dctn5_tv1 was widely distributed and high transcription was observed in immune tissue (skin), while dctn5_tv2 was predominantly detected in gonad and very low in other tissues. Time-course expression analysis revealed that dctn5_tv1 could be up-regulated in gill, intestine, skin, spleen, and kidney after Vibrio harveyi challenge. Moreover, recombinant Dctn5_tv1 exhibited high antimicrobial activity against Escherichia coli and Streptococcus agalactiae due to binding to bacteria cells. Taken together, these data suggest Dctn5_tv1 is involved in immune response of bacterial invasion in Chinese tongue sole.

Establishment and characterization of a kidney cell line from kelp grouper Epinephelus moara.

A novel cell line, Epinephelus moara kidney cell line (EMK), was established from kidneys of kelp grouper E. moara. Cells were cultured at 24 °C in Leibovitz's L-15 medium (L15) supplemented with antibiotics, basic fibroblast growth factor (bFGF), foetal bovine serum (FBS) and 2-mercaptoethanol (2-ME). EMK cells, fibroblastic in morphology, proliferated to 100% confluency in 3-4 days and were subcultured for over 50 passages. The cells could grow from 18 to 30 °C, with optimal growth at 24 °C. Chromosome analysis indicated that the modal chromosome number was 48 in the cells at passage 42. Green fluorescent signals could be observed in EMK cells when the cells were transfected with pEGFP-N3 plasmid. Moreover, a significant cytopathic effect (CPE) was observed in the cells after infection with Singapore grouper iridovirus (SGIV) or nervous necrosis virus (NNV), and viral replication was confirmed by quantitative real-time PCR (qPCR). These results suggested the potential of the EMK cell line for studies of transgene and pathogenesis of SGIV and NNV.

Molecular characterization and expression analysis of a novel r-spondin member (rspo2l) in Chinese tongue sole (Cynoglossus semilaevis).

Numerous studies suggest R-spondins (Rspos) plays a role in mammalian sex development and differentiation by activating WNT signaling pathways. However, Rspos are frequently less reported in teleosts. In this study, a molecular characterization and expression analysis was conducted with a new rspondin member in the Chinese tongue sole, rspondin2-like (rspo2l). The length of rspo2l cDNA is 1251 bp with 732 bp of coding sequence. A qRT-PCR analysis revealed that the transcription of rspo2l was distributed in various tissues, with high transcription levels in the liver, skin, and gills which might indicate a possible role in immunity. We next examined a time-course of transcription levels in four immune tissues (gill, liver, spleen, and kidney) after Vibrio harveyi challenge. It was found that rspo2l was up-regulated in the gills, spleen, and kidney and down-regulated in the liver, and the greatest responses occurred at 24 and 48 h after bacterial challenge. An assessment of ß-catenin, the key regulator of the canonical WNT signaling pathway, at different time points in four immune organs revealed that its transcription profile was similar to that of rspo2l after bacterial challenge. The results suggest that tongue sole rspo2l might play a role in immune responses after bacterial challenge, while the potential link with the WNT signaling pathway still requires further investigation. This is the first report about the involvement of rspondins in fish immune responses.

Insights from the Cold Transcriptome and Metabolome of Dendrobium officinale: Global Reprogramming of Metabolic and Gene Regulation Networks during Cold Acclimation.

Plant cold acclimation (CA) is a genetically complex phenomenon involving gene regulation and expression. Little is known about the cascading pattern of gene regulatroy network and the link between genes and metabolites during CA. Dendrobium officinale (DOKM) is an important medicinal and ornamental plant and hypersensitive to low temperature. Here, we used the large scale metabolomic and transcriptomic technologies to reveal the response to CA in DOKM seedlings based on the physiological profile analyses. Lowering temperature from 4 to -2°C resulted in significant increase (P < 0.01) in antioxidant activities and electrolyte leakage (EL) during 24 h. The fitness CA piont of 0°C and control (20°C) during 20 h were firstly obtained according to physiological analyses. Subsequently, massive transcriptome and metabolome reprogramming occurred during CA. The gene to metabolite network demonstrated that the CA associated processes are highly energy demanding through activating hydrolysis of sugars, amino acids catabolism and citrate cycle. The expression levels of 2,767 genes were significantly affected by CA, including 153-fold upregulation of CBF transcription factor, 56-fold upregulation of MAPKKK16 protein kinase. Moreover, the gene interaction and regulation network analysis revealed that the CA as an active process, was regulated at the transcriptional, post-transcriptional, translational and post-translational levels. Our findings highligted a comprehensive regulatory mechanism including cold signal transduction, transcriptional regulation, and gene expression, which contributes a deeper understanding of the highly complex regulatory program during CA in DOKM. Some marker genes identified in DOKM seedlings will allow us to understand the role of each individual during CA by further functional analyses.

Molecular cloning, structure and expressional profiles of two novel single-exon genes (PoCCR6A and PoCCR6B) in the Japanese flounder (Paralichthys olivaceus).

CCR6 is an important binding receptor of CCL20 and beta-defensins, and has multiple functions in the innate and acquired immune responses. In this study, we cloned the PoCCR6A and PoCCR6B genes of the Japanese flounder and studied the gene structure and expression patterns of these two genes in bacterial infection. The full-length PoCCR6A cDNA is 1415 bp and the open reading frame (ORF) is 1113 bp, encoding a 370-amino-acid peptide. The full-length PoCCR6B cDNA is 2193 bp and the ORF is 1029 bp, encoding a 363-amino-acid peptide. The structures of PoCCR6A and PoCCR6B indicate that they are single-exon genes. The predicted proteins encoded by PoCCR6A and PoCCR6B have the typical G-protein-coupled receptor (GPCR) family signature of seven transmembrane domains and several conserved structural features. A tissue distribution analysis showed that PoCCR6A is predominately expressed in the intestine, gill, and blood, and PoCCR6B in the gill, spleen, and liver. The expression patterns of the two chemokine receptors were analyzed during bacterial infection. In spleen and kidney, the expression of PoCCR6A was significantly upregulated at 24 h after infection, whereas the expression of PoCCR6B was steady at these time points. While in intestine, both of them were upregulated at 6 h-12 h after infection, and in gill the expression levels of them were upregulated at 24 h. The patterns of expression suggested that PoCCR6A and PoCCR6B play an important role in the immune response of the Japanese flounder, especially in the mucosal tissues.

Characterizing diversity based on nutritional and bioactive compositions of yam germplasm (Dioscorea spp.) commonly cultivated in China.

Yams (Dioscorea spp.) are widely cultivated as edible resources and medical materials in China. Characterizing chemical compositions in yam germplasm is crucial to determine their diversity and suitability for food and medicine applications. In this study, a core germplasm containing 25 yam landraces was used to create an effective classification of usage by characterizing their nutritive and medicinal compositions. All studied landraces exhibited high contents of starch from 60.7% to 80.6% dry weight (DW), protein (6.3-12.2% DW), minerals (especially Mg 326.8-544.7 mg/kg DW), and essential amino acids. Allantoin and dioscin varied considerably, with values of 0.62-1.49% DW and 0.032-0.092% DW, respectively. The quality variability of 25 yam landraces was clearly separated in light of UPGMA clustering and principal component analysis (PCA). Using an eigenvalue ≥1 as the cutoff, the first three principal components accounted for most of the total variability (62.33%). Classification was achieved based on the results of the measured parameters and principal component analysis scores. The results are of great help in determining appropriate application strategies for yam germplasm in China.