This study aimed to elucidate the pedigree and traits related to yield and quality of strong gluten wheat varieties bred in middle and lower reaches of the Yangtze River，providing reference for genetic improvement of strong gluten wheat varieties in this region.

Strong gluten and medium-strong gluten wheat varieties proved by national or provincial registration in middle and lower reaches of the Yangtze River were used as materials to analyze their genetic pedigree and contribution values of core parents，and data from regional trials were utilized to analyze their traits related to yield，quality，and diseases resistance.

From 2007 to 2023，a total of 70 strong or medium-strong gluten wheat varieties were registered in this region. The breeding methods included systematic selection，cross breeding，and recurrent selection breeding，among which cross breeding accounted for 95.6% of all developed varieties，with single-cross breeding being the predominant method （65.7%），multiple-cross breeding accounting for 25.6%，with three varie-ties developed through backcross breeding. Pedigree analysis of parents revealed that the strong gluten wheat varieties developed in Jiangsu were mainly derived from Sumai No. 6 and its derivative varieties （Zhenmai No. 9，Zhenmai No. 10，and Zhenmai 168），while those developed in Hubei were mainly derived from Zhengmai 9023 and Xinong 979. Among the superior wheat varieties developed in the middle and lower reaches of the Yangtze River，medium-strong gluten varie-ties accounted for the highest proportion of 58.6%. All varieties met the strong gluten or medium-strong gluten standards in terms of grain protein content and extended area；however，12 varieties failed to meet the quality standard for stability time，five varieties failed for maximum resistance to extension，and five varieties failed to meet the first-class wheat standard for test weight. In terms of yield performance，92.9% of the varieties outyielded the control，with varying degrees of improvement in effective panicle number，kernel number per panicle，and thousand-kernel weight compared with the control. Regarding resistance to Fusarium head blight，the improvement was relatively effective，with 54.3% of varie-ties showing moderate resistance to Fusarium head blight，25.7% showing moderate to high resistance to stripe rust，2.9% showing moderate resistance to sheath blight，and 17.1% showing primary to moderate resistance to powdery mildew.

The breeding of superior strong gluten wheat in middle and lower reaches of the Yangtze River has achieved considerable progress，with 70 high yield and superior strong gluten or medium-strong gluten wheat varieties developed. However，the problems of narrow parental sources and limited genetic basis remain，and thus the introduction and utilization of elite germplasm from other ecological regions or relatives of wheat should be strengthened. For quality improvement，more attention should be paid to the enhancement of gluten quality，and the screening of dough rheological pro-perty indicators should be reinforced. To improve the stable yield and adaptability of superior varieties，resistance to Fusarium head blight needs to be further enhanced，and particular emphasis should be placed on improving resistance to powdery mildew and sheath blight，so as to achieve the goal of superior，high-yield，and green production.

This study aimed to systematically reveal the distribution patterns of repeat sequences in genomic microsatellites of Cynoglossus semilaevis and analyze the functional annotations，providing sequence resources for developing microsatellite molecular markers with potential functional implications and exploring genetic breeding.

Based on the whole-genome sequences of Cynoglossus semilaevis，the microsatellite repeat sequences in genome were screened by bioinformatic methods. GO functional annotation and KEGG signaling pathway enrichment analysis were conducted on genes associated with microsatellites in exonic regions.

A total of 473776 microsatellite loci belonging to six base repeat types were identified in the Cynoglossus semilaevis genome，accounting for 1.62% of the total genome length；the number of microsatellites decreased with the increase in the base number of repeat units，and mononucleotide and dinucleotide microsatellites accounted for 84.85% of all microsatellites，with a significant positive correlation between chromosome length and number of contained microsatellites （P<0.05，the same below）. Among different repeat motif types in genomic microsatellites of Cynoglossus semilaevis，the A/T motif was the most abundant in mononucleotide repeats，and the AC/GT motif was the most abundant in dinucleotide repeats，and the numbers of each type of microsatellite decreased with the increase of motif repeat times. The significantly enriched GO functional terms of genes containing microsatellites in genomic exonic regions of Cynoglossus semilaevis were regulation of transcription by RNA polymerase II and protein phosphorylation. The KEGG signaling pathway enrichment analysis results showed that the significantly enriched signaling pathways for genes containing microsatellites in genomic exonic regions of Cynoglossus semilaevis included starch and sucrose metabolism within the metabolism category and necroptosis within the cellular process，followed by the tight junction within the cellular process.

Genomic microsatellites of Cynoglossus semilaevis are mainly composed of mononucleotide and dinucleotide repeats，and a significant positive correlation is found between the number of microsatellites and chromosome length，with the number decreasing as motif repeat number rises. Microsatellites in exonic regions are significantly enriched in signaling pathways associated with transcriptional regulation，energy metabolism，and immune response，and they probably participate in the adaptive regulation of Cynoglossus semilaevis under environmental stresses such as hypoxia.

This study aimed to establish a hypoxia stress model for Pelteobagrus vachelli，clarify the response mechanism of related genes in the gill tissue to hypoxia stress，providing data support for further exploration of its gill tissue hypoxia adaptive regulation and theoretical basis for screening highly adaptive populations of Pelteobagrus vachelli.

One-year-old Pelteobagrus vachelli were used as research subjects，and three treatment groups were set ［control group （C：dissolved oxygen content of 6.50 ± 0.10 mg/L），hypoxia group （H：dissolved oxygen content of 0.75 ± 0.10 mg/L，6 h），and recovery group （R：dissolved oxygen content of 6.50 ± 0.10 mg/L，6 h）］. Gill tissue samples were collected to extract RNA，and differentially expressed genes （DEGs） were screened by transcriptome sequencing. GO functional annotation analysis and KEGG signaling pathway enrichment analysis were performed，and real-time fluorescence quantitative PCR was used for verification.

The results showed that raw data of 57.72 Gb were detected through sequencing nine samples from Group C，Group H，and Group R. According to the reference genome，a total of 22116 genes were annotated and 1824 new genes were found. For the Group C vs Group H，554 DEGs were detected，in which 270 were up-regulated and 284 were down-regulated；for the Group C vs Group R，42 DEGs were detected，in which 12 were up-regulated and 30 were down-regulated；for the Group H vs Group R，993 DEGs were detected，in which 470 were up-regulated and 523 were down-regulated. DEGs were mainly annotated to GO functional items such as cellular process，single-organism process，metabolic process，binding，catalytic activity，nucleic acid binding transcription factor activity，signal transducer activity，cell part，membrane，and cell. KEGG signaling pathway enrichment analysis found that DEGs were mainly enriched in signaling pathways such as breast cancer，pathways in cancer，basal cell carcinoma，cytokine-cytokine receptor interaction，chemical carcinogenesis-DNA adducts，and metabolism of xenobiotics by cytochrome P450. The real-time fluorescence quantitative PCR detection results showed that the expression trends of partial DEGs between groups were overall consistent with the transcriptome sequencing results.

Hypoxia stress inhibits the cell proliferation and signaling pathways of Pelteobagrus vachelli to some extent，lea-ding to inhibition of the tricarboxylic acid cycle and anaerobic respiration activation，and gill tissue up-regulates expression of glycometabolism gene to promote glucose breakdown to produce energy. Activation of the glycolytic pathway leads to pyruvate accumulation，meanwhile，pyruvate kinase expression is inhibited at the transcriptional level，accompanied by a partial activation of gluconeogenesis pathway. Changes in heat shock protein gene expression may counteract hypoxic stress by inhibiting the autophagy pathway to reduce energy consumption.

This study aimed to investigate change patterns of aroma substances of Akebia trifoliata ssp. australis pulp during ripening，providing reference for fruit quality regulation and development and utilization of aroma substances of Akebia trifoliata ssp. australis.

Fruits at hard ripening （Y0），softening （R0），cracking （K0），and ripening （Y3） stages of the variety Yemutong Ⅰ of Akebia trifoliata ssp. australis were taken as test materials. Widely targeted metabolomic analysis and relative odor activity value （ROAV） analysis were performed，and KEGG metabolic pathway enrichment and sensory flavor were analyzed based on differential volatile metabolites.

A total of 448 volatile metabolites were detected in pulp of Yemutong Ⅰ at the four stages，with terpenoids and heterocyclic compounds being the most abundant. During the whole tree ripening process of Y0→R0→K0，the differential volatile metabolites were mainly up-regulated；the differential volatile metabolites were mainly down-regulated during the process of Y0→Y3 at room temperature. In Y0 vs R0，the significantly enriched pathway of differential volatile metabolites was biosynthesis of cofactor （P<0.05，the same below），while in Y0 vs K0 and Y0 vs Y3，the significantly different metabolic pathway was sesquiterpenoid and triterpenoid biosynthesis，followed by biosynthesis of cofactor. A total of 70 key odor components with ROAV > 1 were identified，among which benzyl mercaptan，3,6-nonadienal，5-ethyl-3-hydroxy-4-methyl-2（5H）-furanone，phenylethyl isovalerate，and other substances showed great influence on shaping pulp odor of Yemutong Ⅰ. ROAV analysis results showed that the odor characteristics of pulp at each ripening stage were relatively consistent：sweet odor type was dominant，with a contribution rate of 84.40%-89.89%，followed by spicy and floral odor types，with contribution rates of 2.89%-5.02% and 2.71%-3.35% respectively. Fruity and green odor types were the common sensory flavor characteristics annotated to the differential volatile metabolites across all comparison groups.

Pulp of Yemutong Ⅰ exhibits a complex odor type covering green，fruity，and sweet odors，forming a distinctive flavor characteri-zed by sweet and refreshing，tender and smooth，with rich fruity odor and a subtle hint of coconut substances. During the two ripening processes of tree-ripening and post-harvest ripening at room temperature，the overall pulp odor exhibits relatively minor changes. Therefore，fruits harvested at the softening stage are suitable for fresh consumption or short distance transportation，while those at the hard-ripening stage are more appropriate for storage and long distance transportation.

This study aimed to analyze the genetic differences in karyotypes and phenotypic traits of BC₁F₂ materials of sugarcane and Erianthus fulvus hybrids and elucidate the association between phenotypic traits and chromosome numbers，providing theoretical basis for innovation and utilization of sugarcane germplasms.

The BC₁F₁ materials 16-12 （2n=104） produced by backcrossing of sugarcane Dianzhe 01-58 （2n=100） and Erianthus fulvus （2n=20） were used for selfing to obtain 21 BC₁F₂ materials. The chromosome number counting，karyotype analysis，and phenotypic trait determination were performed to conduct correlation analysis，principal component analysis，and cluster analysis for elucidating the association between chromosome number and phenotypic traits.

The chromosome numbers of the 21 BC₁F₂ materials fell into six types，namely 2n=98，100，102，104，106，and 108. Among the 21 BC₁F₂ materials，except for 20-129 whose karyotype was 3B，the karyotypes of the other 20 BC₁F₂ materials were 2B，showing a relatively symmetrical karyotype. The majority of chromosomes had metacentric centromeres （m），while a minority possessed submetacentric centromeres （sm），with the proportion of metacentric chromosomes ranging from 57.00% to 87.25%. The coefficients of variation of phenotypic traits of BC₁F₂ materials and the parent 16-12，as well as Erianthus fulvus ranged from 9.32% to 42.59%，with an average coefficient of variation of 20.71%. Different degrees of correlations were found between seven phenotypic traits and chromosome number，and extremely significant positive correlations were found between plant height and single-stalk weight，between stalk diameter and leaf width，single-stalk weight，chromosome number，between leaf width and single-stalk weight，chromosome number，and between single-stalk weight and chromosome number （P<0.01，the same below）. Extremely significant negative correlations were observed between brix and plant height，single-stalk weight，between plant height and leaf length，and between internode length and chromosome number. Significant positive correlation was found between plant height and internode length. Significant negative correlations were observed between brix and internode length，between stem diameter and internode length，and between leaf length and single-talk weight. Principal component analysis results showed that the first three principal components exhibited cumulative contribution rate of 77.92%，with the first principal component （PC1） showing an eigenvalue of 3.11 and a contribution rate of 38.91%，and chromosome number，single-talk weight，leaf width，and stalk diame-ter were principal determination factors. Cluster analysis showed that the BC₁F₂ materials and the parents （16-12 and Erian-thus fulvus） were divided into five groups. Group I consisted of eight materials，characterized mainly by long leaves；Group II consisted of six materials，characterized mainly by wide leaves；Group III contained only one material，characterized mainly by high brix；Group IV contained seven materials，characterized mainly by greater plant height and high single-stalk weight；Group V contained only one material，Erianthus fulvus，characterized mainly by long internodes，lower stalk diameter，and low brix.

Correlations of varying degrees are found between phenotypic traits and chromosome number of BC₁F₂ materials，demonstrating that obvious genetic differences in phenotypic traits are due to different chromosome numbers of BC₁F₂ materials. These hybrid progeny materials with Erianthus fulvus genetic background can be used for subsequent sugarcane breeding.

This study aimed to investigate digestive tract microstructure characteristics and dietary chara-cteristics of Mastacembelus armatus，providing theoretical reference for artificial propagation and domestication，population resource conservation and restoration，and appropriate utilization of wild Mastacembelus armatus.

Hematoxylin-eosin （HE） staining was used to observe the digestive tract microstructure of Mastacembelus armatus，and DNA metabarcoding technology was utilized to analyze its dietary characteristics.

The digestive tract of Mastacembelus armatus composed of four layers：the mucosal layer，submucosa，muscular layer，and serosal layer. The longitudinal folds of the mucosal layer in the esophagus were well-developed with branches，and the surface was covered with stratified squamous epithelium，with goblet cells interspersed among the epithelial cells. The stomach was the most expanded organ of the digestive tract，with the mucosal layer protruding inward to form mucosal folds，consisting of the lamina propria and simple columnar epithelium，with no goblet cells observed. The intestinal villi were well-developed，and the fold height in the foregut was significantly higher than that in the midgut and hindgut （P<0.05）. A total of 409 species belonging to 24 phyla were identified from the stomach contents using 18S rDNA metabarcoding sequencing. At phylum level，the dominant groups were Arthropoda，Annelida，and Chlorophyta. At species level，the dominant species included Phyllomacromia nyanzana，Amynthas sp. GZ201102-03，and Macrobrachium superbum. The feeding selectivity analysis revealed that Mastacembelus armatus exhibited a strong preference for Annelida and Arthropoda，while showing a distinct avoidance tendency toward Chlorophyta，Bacillariophyta，and Gastrotricha，which were relatively abundant in the aquatic environment. No fundamental shift in the major dietary components was observed across different body length groups of Mastacembelus armatus，with Annelida and Arthropoda as the dominant groups at phylum level.

The digestive tract structure of Mastacembelus armatus exhibits typical morphological adaptations of carnivorous fish，characterized by a lubricating esophagus-expanded stomach-absorption dominated by foregut pattern. Mastacembelus armatus is a euryphagous carnivorous fish，and its feeding selection conforms to the optimal foraging theory，showing strong active selectivity for Arthropoda and Annelida at both phylum and species levels，while exhibiting avoidance toward low-trophic-level phytoplankton. With individual development，the limitations of mouth gape and energy metabolism demands drive its dietary preference to shift toward arthropod groups.

This study aimed to observe and analyze microstructure and ultrastructure of gill tissue in Hucho bleekeri and enrich its basic biological data，providing reference for elucidating the association between gill structure characteristics and life habits in fishes.

The F₁ generation of artificially bred Hucho bleekeri was used as the research subject. Gill tissue samples were collected and fixed in 4% paraformaldehyde and 3% glutaraldehyde respectively. After paraffin embedding and sectioning，the samples were sequentially subjected to hematoxylin-eosin （HE） staining，Alcian blue-periodic acid Schiff （AB-PAS） staining，Masson staining，and Sirius red staining. The histological morphology，mucous cell types，and distribution and classification of collagen fibers were observed under a light microscope. Meanwhile，the ultrastructure of gill tissue was examined using scanning electron microscopy and transmission electron microscopy.

Hucho bleekeri possessed four pairs of gills. The gill rakers were milky-white，needle-shaped，and sparsely arranged （12-14 rakers）. The gill filaments were bright red and elongated，gradually tapering from the base toward the distal end，with the terminal portion remaining free. The gill arch was primarily composed of cartilaginous tissues and covered by stratified epithelial cells. The gill filament surface was distributed with mucous cells and chloride-secreting cells，with chondrocytes providing central support. The gill lamella consisted of respiratory epithelium and pillar epithelium，and the extended cell bodies of two adjacent pillar cells enclosed the capillary lumen，within which erythrocytes were visible. AB-PAS staining results indicated that mucous cells in gill tissue predominantly secreted neutral mucopolysaccharides （PAS-positive），accompanied by a small amount of acidic mucopolysaccharides （AB-positive）. Masson staining revealed that collagen fibers were evenly distributed in gill tissue，with a collagen fiber tissue area proportion of 0.21%-0.31% （the mean was 0.27%），and no typical lesions such as fibrosis were observed. Sirius red staining results showed that type I collagen fibers accounted for 80.00%-90.49%，type Ⅲ collagen fibers accounted for 9.51%-19.20%，and the ratio of type I/type Ⅲ collagen fibers ranged from 4.21 to 9.51. Scanning electron microscopy observation revealed that the gill raker surface was uneven and porous；the epithelial cells of gill arches and filaments possessed dense circular microridges arranged in a fingerprintlike pattern；mucus was found on both gill filament surface and gill lamellae，but the number of pores on gill filament surface exceeded that on the gill lamellae. Transmission electron microscopy observation revealed that the gill lamella was mainly composed of flattened epithelial cells，pillar cells，chloride-secreting cells，macrophages，erythrocytes，endothelial cells，and neutrophils in the vascular lumen. Among these，the chloride-secreting cells had an elongated oval nucleus，with the long diameter at 8.3 µm and short diameter at 5.6 µm approximately，and the cytoplasm had abundant mitochondria and rough endoplasmic reticulum.

The gill tissue structure in Hucho bleekeri is highly adapted to its carnivorous nature and the habitat of high altitude，low temperature，and fast-flowing freshwater. Moreover，the gill tissue of Hucho bleekeri have immune cells such as macrophages and neutrophils，constituting a specific mucosal immune barrier that plays an important role in innate immune system.

This study aimed to clarify the histological characteristics and cellular composition of major immune organs of Acipenser dabryanus，a rare and endangered fish species endemic to China，laying theoretical foundation for disease control and health management of this species.

Artificially bred F₂ generation of Acipenser dabryanus were used as experimental subjects. Gross anatomy was performed to determine anatomical locations of major immune organs （spleen，head kidney，and thymus）. Histological sectioning techniques ［hematoxylin-eosin （HE） staining，Masson staining，and modified Gomori ammoniacal silver staining］，combined with transmission electron microscope，were used to observe histological characteristics and cellular ultrastructure of spleen，head kidney，and thymus.

The spleen surface of Acipenser dabryanus was covered by an uneven smooth muscle layer，whereas no trabecular structures extending from capsule into the spleen parenchyma were observed. The mesothelial cells in outer capsule layer exhi-bited two morphological forms （squamous and nearly round）. The spleen parenchyma exhibited an interwoven distribution of white pulp and red pulp，with a highly developed vascular system and numerous lymphocytes，nucleated erythrocytes，and melanomacrophages distributed throughout. Transmission electron microscope observation revealed abundant immune effector cells，including lymphocytes，macrophages，and granulocytes in the spleen tissue. Phagosomes were observed in macrophages，indicating that the spleen was involved in blood filtration and non-specific immune functions. The head kidney was located at the anterior end of the kidney and symmetrically distributed as left and right lobes，with absent nephrons and loss of excretory function. Masson staining and modified Gomori ammoniacal silver staining showed that reticular cells，endothelial cells，interwoven reticular fibers，and collagen fibers formed a three-dimensional supporting framework in head kidney tissue，providing an essential microenvironment for the development and differentiation of various immune cells. Lymphocytes，macrophages，and eosinophils with densely distributed elongated or rod-shaped specific granules in cytoplasm were observed in head kidney tissue that functioned as a major lymphoid organ of Acipenser dabryanus with both hematopoietic and immune functions. The thymus of juvenile Acipenser dabryanus was located within the connective tissue in posterior dorsal region of the branchial cavity，adjacent to the gill tissue，making routine non-destructive isolation difficult. In 30-day-old juveniles，the thymic parenchyma showed a relatively uniform internal structure，with no obvious division between the cortex and medulla or between the inner and outer regions. The free margin of thymus was covered by a continuous epithelial cell layer composed of squamous epithelial cells and some columnar epithelial cells，which mainly served as a physical barrier. Many deeply stained thymocytes were densely distributed within the thymus parenchyma. Irregular reticuloendothelial cells were scattered among thymocytes，and together they formed a stromal network supporting the proliferation and maturation of T lymphocytes.

The spleen，head kidney，and thymus of Acipenser dabryanus are distinctive in tissue structures，with clear functional divisions. The organs constitute a well-developed immune defense network，providing a cell biological basis for resistance to pathogen invasion and maintenance of homeostasis in Acipenser dabryanus.