With the rapid development of the novel-tea beverage industry, market competition has significantly intensified. To enhance competitiveness, novel-tea beverage enterprises have increasingly adopted cross-border innovation strategies aimed at upgrading product quality, optimizing the consumer experience, and strengthening brand loyalty. However, the theoretical and empirical understanding of how cross-border innovation enhances brand loyalty is still limited. Utilizing quantitative empirical methods, this study investigated the impact of horizontal and vertical cross-border innovation on consumer brand loyalty based on survey data of 1 900 young novel-tea beverage consumers. The findings reveal that both forms of cross-border innovation contribute to strengthening brand loyalty, with upstream cultural integration within vertical cross-border innovation demonstrating the strongest effect. Furthermore, cross-border innovation primarily influences brand loyalty indirectly by satisfying consumers’ quality demands and enriching consumption experiences, with quality appeal serving as the core mediating mechanism. Additionally, the selection of cross-border innovation strategies is contingent upon enterprise positioning: high-end brands benefit more from horizontal and upstream cultural cross-border innovation, while mid-to-low-end brands achieve brand loyalty enhancement through scenario-based downward cross-border innovation. Based on the above conclusions, this paper proposed some countermeasures and suggestions on how to carry out cross-border innovation marketing.

Nitrogen metabolism genes play a key role in tea plants′ response to various environmental stresses. They do this mainly by regulating metabolites in different pathways. In recent years, significant progress has been made in the study of nitrogen metabolism genes in tea plants using techniques such as transcriptome and metabolome analysis, genome identification. However, there are still many scientific problems that need to be solved urgently, such as the low genetic transformation efficiency of tea plants, the limited research on gene epigenetics, and the limited application of gene breeding in production. This article systematically summarized the expression patterns of nitrogen metabolism genes in tea plants under different stress conditions, organs, and soil elements, as well as the research progress on the regulation mechanism of carbon and nitrogen balance in tea plants under different stresses, revealing the importance of these genes in tea plant stress adaptation and quality improvement. In addition, the research methods, transgenic technology, and breeding applications of nitrogen metabolism genes in tea plants were discussed in order to provide reference for the study of nitrogen metabolism gene regulation mechanisms and breeding research in tea plants.

Alkaloids, as a class of nitrogen-containing secondary metabolites characterized by remarkable chemical diversity, are widely distributed in higher plants, fungi, and bacteria. Most natural alkaloids possess biological activities such as antioxidant, anti-inflammatory, and anti-tumor effects. This review comprehensively summarized the identified alkaloid groups in tea and briefly analyzed their biological activities, including: (1) purine alkaloids, which regulate neural excitability by antagonizing adenosine receptors and inhibiting phosphodiesterase to regulate metabolic functions, exhibit anti-inflammatory, and other biological activities. (2) flavor alkaloids have effects in preventing diabetes and inhibiting cancer cell angiogenesis. (3) the mechanisms by which prenylated indole alkaloids exert anti-inflammatory effects, inhibit cancer cell growth and exert neuro-protective effects. Finally, the future research directions focusing on the identification, appraisal, synthesis and functional evaluation systems of tea alkaloids were proposed.

This study investigated the characteristic aroma components and microbial diversity during long term and short term fermentation processes of Anhua black tea. The research employed headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS), as well as 16 S rRNA and ITS high-throughput sequencing technologies. The results show that 82 volatile components were detected in Anhua black tea with distinct fermentation processes, mainly include alcohols, esters, and aldehydes, collectively accounting for approximately 85% of the total volatile content. The overall volatile components initially increased and subsequently decreased during processing. Based on thresholds of odor activity value (OAV)>1 and variable importance in projection (VIP)>1, 14 key differential volatile components were identified in the black tea of short and long term fermentation processes, including citral, linalool, phenethyl alcohol, phenylacetaldehyde, methyl salicylate, β-myrcene, β-ionone, et al. The dominant bacteria of Anhua black tea include Sphingomonas, Methylobacterium, Aureimonas, and the dominant fungi include Cladosporium, Alternaria and Setophoma. The genera Aureimonas, Enterobacter, Aspergillus, and Pseudopithomyces were significantly correlated with distinct fermentation processes. This study provided a theoretical reference and basis for the scientific processing and flavor analysis of Anhua black tea.

To further clarify the effects of the main compounds in white tea on blood glucose levels, the network pharmacology was used to conduct a correlation analysis between 8 main compounds in white tea and diabetes, and a zebrafish biological model was adopted for verification. The network pharmacology analysis reveals that blood glucose was primarily regulated by gallic acid, catechin group, and caffeine in white tea through four targets: TNF, p53, SRC and CASP3. The verification results of the zebrafish model show that the maximum tolerance concentrations of zebrafish to the different samples were as follows: 100.00 µg·mL^-1 (white tea soup), 6.25 µg·mL^-1 (gallic acid, caffeine), 12.50 µg·mL^-1 (EGCG), 25.00 µg·mL^-1 (ECG, EGC, GCG), 50.00 µg·mL^-1 (EC), and 150.00 µg·mL^-1 (C). At this concentration, the blood glucose values decreased significantly in all groups compared with the model group: the positive drug (ACA) group by 53.7%, the white tea soup group by 16.2%, the gallic acid group by 33.6%, the EGCG group by 47.3%, the ECG group by 30.0%, the EGC group by 52.6%, the GCG group by 25.8%, the EC group by 21.5%, and the C group by 29.4%. Only the caffeine group showed a significant blood glucose-elevating effect (P<0.05), with an increase of 16.9%. The qPCR results show that, compared with the blank group, the expression levels of TNF, SRC and CASP3 in the model group were significantly increased, while the expression level of TP53 was significantly decreased (P<0.05). Compared with the model group, the expression levels of TNF, SRC and CASP3 in the gallic acid and catechin groups were significantly decreased (P<0.05), while the expression level of TP53 was significantly increased (P<0.05). The expression levels of TNF and SRC in the caffeine group were significantly increased (P<0.05), while there were no significant differences in TP53 and CASP3. The results show that gallic acid and catechin components in white tea both exhibited significant hypoglycemic effects, which were mainly achieved by regulating four targets: TNF, p53, SRC and CASP3. In contrast, caffeine was found to have a significant blood glucose-elevating effect, primarily through TNF and SRC.

To explore the effects of tea light complementary mode on the growth environment, yield performance and economic benefits, the microclimate environment such as temperature, humidity and light in the tea garden-PV complementary model was analyzed in this study with the open-air tea garden as a control. Indicators such as tea bud germination and growth, photosynthetic rate, and fresh leaf yield were detected, and the photovoltaic power generation was simulated and calculated. The overall economic benefits of the tea garden were analyzed. The results show that the photosynthetically active radiation of the tea canopy in photovoltaic tea gardens was lower than that in open-air tea gardens. The average minimum temperature of tea canopy in photovoltaic tea gardens at night in spring (March) was 0.63 ℃ higher than that in open-air tea gardens, and the average maximum temperature in daytime in summer (July) was 1.80 ℃lower than that in open-air tea gardens. The average relative humidity of tea canopy in photovoltaic tea gardens was higher than that in open-air tea gardens. The tea buds in photovoltaic tea gardens germinated and grew faster, and the utilization efficiency of light radiation was higher. The yield per unit area of the picking area in different harvesting seasons was 9.74%-28.84% higher than that of the open-air tea gardens. The overall output of the tea garden decreased by 23.11% to 34.16% due to the occupation of land for the construction of photovoltaic modules. The annual income of photovoltaic tea gardens, including power generation revenue, was 6.030×10⁵ CNY per hectare, while the annual income of open-air tea gardens was 2.249×10⁵ CNY. Considering the one-time investment cost of 3.740 3 million CNY for building photovoltaic modules, the total revenue of photovoltaic tea gardens will exceed that of open-air tea gardens after 9 years. This study has certain guiding and referential significance for the application and promotion of the tea-light complementary agricultural model in southern China.

In recent years, multi-arm tea-picking robots have become a research hotspot due to the shortage of labor, rising labor costs, and the demand for high-precision picking in the high-quality tea industry. A collaborative planning method that dynamically allocates the space for picking points was proposed, and the path planning of the robotic arm was optimized by combining the ant colony algorithm and the picking point priority in order to improve the operational efficiency of the tea-picking robot. Simulation results show that the average time for one-shoot picking was 1.41 s, and the time ratio for dual-arm synchronous operation was 91.95%. Compared to the 62.86% coverage rate of the two-space segmentation method, this method achieved full coverage of the space. To overcome the limitations of the existing independent operation mode of the depth camera, a dynamic addition of picking point planning was further proposed, which realized the synchronous operation of the depth camera and the robotic arm. Field experiment results show that the tea-picking robot adopts the picking point allocation method that dynamically divides the operating space and the double-arm collaborative planning method that dynamically divides the space for picking point allocation. The average time for one-shoot picking was 1.52 s, a 29.95% improvement compared to the one-arm tea-picking robot. This method not only significantly improves the operational efficiency of the tea-picking robot but also achieves full coverage of the space, ensuring efficient collaborative picking.

The effects of different pH and digestive enzymes in tea soup on tea polyphenols (TP), catechins (CATE) and their antioxidant activities were investigated by using an in vitro simulated digestion model, and the differences between dry tea and instant tea powder were compared. The TP concentration was determined by Folin phenol method, and the catechins were quantitatively analyzed by high performance liquid chromatography (HPLC). The antioxidant activities of the two kinds of tea soups were comprehensively evaluated by Ferric reducing ability of plasma (FRAP), 1,1-diphenyl-2-trinitrophenylhydrazine free radical (DPPH) and 2,2ʹ- diazo-bis-3-ethylbenzothiazoline-6-sulfonic acid free radical (ABTS). The results show that the TP concentration (874.19 mg·L^-1) of black instant tea powder before simulated digestion was 1.59 times that of dry tea soup (551.50 mg·L^-1), the cate concentration (239.58 mg·L^-1) was 1.68 times that of dry tea soup (142.98 mg·L^-1), and the antioxidant activity was about twice that of dry tea soup. After gastrointestinal simulated digestion, the stability of tea soup cate and antioxidant activity of black instant tea powder were lower than that of dry tea, which may be related to the high proportion of epigallocatechin gallate (EGCG)+epigallocatechin (EGC) in instant tea soup and its intestinal degradation law. Both pH 2.0 and pH 7.0 decreased the antioxidant activity of tea soup, and the effect of acidic pH was greater. The addition of pepsin, TP and cate increased the antioxidant capacity of tea soup, while the addition of bile salt and trypsin decreased the FRAP value of tea soup. To sum up, the preparation of instant tea powder, pH and the phased action of digestive enzymes could affect the digestion stability of catechins in tea. By optimizing the extraction parameters of instant tea, the changes of catechins in tea can be reduced, and the influence of gastric acid environment during instant tea drinking can be avoided, so as to improve the bioavailability of catechins in tea leaves.

To investigate the dynamic changes of the characteristic aroma of Xinyang Maojian during processing and the impact of water treatment processes on its aroma, this study took Xinyang Maojian tea made from the tea cultivar ‘Xinyang 10’ as the research object. The aroma components and their relative contents in samples of different stages, including fresh leaves, fixation, rehumidification, rolling, shaping, and drying, using both water treatment and traditional methods, were identified and analyzed using headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) technology. The results show that a total of 81 volatile metabolites were identified in the experimental samples, among which high contents of esters, terpenes, and heterocyclic compounds were found in Xinyang Maojian and they were considered as the main aroma-contributing substances. After fresh leaves were treated with water, the contents of volatile components decreased rapidly, and then tended to be stable in each processing stage. Compared with the traditional process, there were 7 volatile components with significant differences in the aroma components of the finished tea processed by water treatment, among which 4 volatile components had higher relative odor activity value (ROAV) in the water treatment samples than in the traditional process. This study deeply analyzed the dynamic changes of aroma components during the Xinyang Maojian processing and the impact of water treatment technology on its aroma. This paper provided a scientific basis for the quality improvement of Xinyang Maojian and the application of water treatment technology.

To clarify the occurrence species of Helopeltis, which is an important tropical economic pest in tea gardens of China, a total of 1 710 samples of Helopeltis adults were collected from 14 tea gardens in Hainan, Guangdong, Guangxi and Yunnan provinces. The collected bugs were reared in laboratory, and the morphology of eggs, nymphs and adults were observed. Three species were identified, including H. theivora Waterhouse, H. cinchonae Mann, and H. fasciaticollis Poppius. H. cinchonae was first found in tea gardens of China, H. cinchonae and H. theivora were the main species of Helopeltis in tea gardens of China. Damage characteristics of the three species on tea plants were similar. The three species could be distinguished based on the color of body and the antennae of males. The research shows that there were at least 3 species of Helopeltis in tea gardens of China.

Anthocyanins exhibit diverse health benefits in humans, including antioxidant and anticancer effects, making them a key target for functional crop breeding. Anthocyanin synthase (ANS), a pivotal enzyme in anthocyanin biosynthesis, has been demonstrated to regulate anthocyanin accumulation in various crops. However, functional studies on ANS genes in tea plants (Camellia sinensis) remain limited. In this study, we identified a specifically highly expressed CsANS1 gene in the purple leaves of tea cultivar ‘Zijuan' through comparative transcriptome analysis of four tea cultivars with distinct leaf colors. Gene expression analysis reveals that CsANS1 expression in ‘Zijuan' was significantly higher than in other cultivars and other ANS family members (CsANS2 and CsANS3) in tea plants. Tissue-specific expression analysis further demonstrats that CsANS1 exhibited the highest expression level in ‘Zijuan' leaves, showing an expression trend of first increasing and then decreasing with the development of buds and leaves. Phylogenetic analysis indicats that sequence similarity among ANS gene copies within species is higher than that among interspecies homologs, and all members of the tea ANS family possess the highly conserved Fe(Ⅱ)/2OG dioxygenase domain. Comparative gene sequencing and protein tertiary structure prediction analyses reveal two non-synonymous mutations in the coding region of CsANS1 in ‘Zijuan', with the amino acid variation at position 165 potentially affecting local protein conformation. Following VIGS-mediated silencing of CsANS1, the anthocyanin content in ‘Zijuan' shoots significantly decreased, accompanied by a lightening of leaf color. In conclusion, this study confirms that CsANS1 is a key gene regulating high-level anthocyanin accumulation in ‘Zijuan' buds and leaves, providing an important molecular target for breeding high-anthocyanin tea cultivars.

To investigate the effects of geographical origin and cultivar on green tea quality, this study analyzed the liquor color, physicochemical components, and in vitro antioxidant activities of eight green teas from Longnan, Gansu and Jinhua, Zhejiang. Correlation and cluster analyses were employed for a comprehensive evaluation. The results show that compared to Longnan green teas, Jinhua green teas exhibited brighter green liquor color and a fresher, sweeter aftertaste. In contrast, Longnan green teas contained higher levels of tea polyphenols, flavonoids, caffeine, vitamin C (VC), catechins, and mineral elements, as well as superior in vitro antioxidant activities, including DPPH radical scavenging ability, ABTS radical scavenging ability, hydroxyl radical (·OH) scavenging ability, and total antioxidant ability (T-AOC). Among the tested cultivars, Longnan Camellia sinensis cv. ‘Yunfeng 5' and Jinhua Camellia sinensis cv. ‘Jiaming 1' had the best overall quality and antioxidant performance. The correlation results show that the color, physical and chemical components and antioxidant capacity of tea decoction were closely correlated. Among them, tea polyphenols, VC and epigallocatechin gallate (EGCG) were positively correlated with the antioxidant ability of the four kinds of tea decoction (P<0.01). Cluster analysis divided the samples into two distinct groups corresponding to their geographical origins, indicating that origin had a greater influence on tea quality than cultivar. This study provided a theoretical foundation for evaluating the effects of geographical origin and cultivar on the antioxidant properties of green tea.

Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to analyze the contents and composition of 10 α-dicarbonyl compounds in tea by detecting stable quinoxaline derivatives formed by reactions between α-dicarbonyl compounds and o-phenylenediamine. The results demonstrate that 3-deoxyglucosone was the predominant dicarbonyl compound in all six major tea categories. The high-temperature de-enzyming process was identified as the primary driver for the formation of short-chain α-dicarbonyl compounds in green tea, yellow tea and oolong tea. While relatively lower drying temperatures significantly influenced the formation of long-chain α-dicarbonyl compounds in white tea and dark tea. The total contents of α-dicarbonyl compounds in green tea, yellow tea, black tea and oolong tea exhibited an increasing trend with the oxidation degree of catechins. Additionally, the absence of rolling during white tea processing and microbial activity during the pile-fermentation process of dark tea were critical factors for the accumulation of α-dicarbonyl compounds.

‘Huangjincha’ is a tradtional and local tea germplasm resource in Xiangxi, with an excellent flavor quality, especially its obvious aroma characteristics, which is highly favored by consumers. This study selected four tea cultivars, namely ‘Baojing Huangjincha 1’, ‘Huangjincha 2’, ‘Huangjincha 8’, ‘Huangjincha 18’, to produce ‘Huangjincha’ green and black tea samples. Sensory evaluation, gas chromatography-mass spectrometry (GC-MS), and relative odor activity value (ROAV) were used to analyze their aroma components. The results show that ‘Huangjincha’ green tea is characterized by its fresh and elegant aroma and a refreshing, sweet aftertaste, while ‘Huangjincha’ black tea exhibits distinct sweet and floral notes. A total of 101 volatile aroma compounds were detected in ‘Huangjincha’ green tea. Among these, esters and alcohols accounted for 34.4% to 53.5% and 21.9% to 36.3%, respectively. A total of 140 volatile aroma compounds were detected in ‘Huangjincha’ black tea, with alcohols, esters, and aldehydes being the main volatile components, accounting for 38.6% to 60.0%, 11.0% to 26.9%, and 9.7% to 17.8%, respectively. The primary aroma-contributing compounds of both ‘Huangjincha’ green and black tea were further screened. A total of 20 compounds were identified as key contributors to the aroma of ‘Huangjincha’ green tea, including linalool, 3,5-octadien-2-one, cis-jasmone, β-ionone, lauric acid, β-cyclocitral, and 2-pentylfuran. For ‘Huangjincha’ black tea, 33 shared key aroma components compounds were identified, including linalool, benzaldehyde, 3,5-octadien-2-one, trans-β-ionone, (Z)-linalool oxide (furanoid) and 4-heptenal. This study had preliminarily revealed the similarities and differences in aroma quality characteristics and chemical composition in ‘Huangjincha’ green and black tea made by different cultivars, which could be used to improve the processing technology system of ‘Huangjincha’.

To elucidate the quality characteristics of Yihong black tea, a systematic analysis was conducted on the quality attributes of Yihong black tea with different levels of tenderness based on sensory evaluation, colorimetric analysis, and targeted metabolomics. The results demonstrate that sensory evaluation scores exhibited a positive correlation with leaf tenderness. The theaflavin content exhibited an initial increase followed by a decline with the decrease in leaf tenderness, and the content of theaflavins was positively correlated with the color parameter L^* value of the tea infusion. The soluble sugar content elevated with the decrease in leaf tenderness, whereas the contents of tea polyphenols and total free amino acids gradually declined. Furthermore, a total of 162 non-volatile metabolites were identified based on the UPLC-MS/MS. Among them, 24 characteristic metabolites were characterized as marker compounds for distinguishing Yihong black tea with different levels of tenderness, including 10 flavonoids [hyperoside, kaempferol-3-O-(6''-trans-P-coumaroyl-2''-glucosyl) rhamnoside, quercetin 3-rutinoside-7-glucoside, keracyanin, kaempferol 3-rutinosidea, astragaline, kaempferol 3-O-galactoside, quercetin 3-rutinoside-7-galactoside, quercetin 3-O-rhamnoside-7-O-glucoside, quercetin 3-rutinoside], 7 catechins [(+)-catechin, catechin gallate, epicatechin, (-)-epigallocatechin, (-)-gallocatechin gallate, epigallocatechin gallate, (-)-epicatechin gallate], 4 amino acids [L-phenylalanine, L-arginine, D-(+)-pipecolinic acid, L-(-)-pipecolinic acid], 3 alkaloids [caffeine, theobromine, adenosine]. These results clearly defined the typical quality attributes of Yihong black tea as “amber-hued liquor, and a honeyed fruity bouquet” and further elucidated the characteristic metabolites responsible for the quality differences in Yihong black tea with different levels of tenderness, providing a scientific basis for optimizing processing techniques and precisely modulating flavor profiles, and facilitating standardized processing and quality enhancement of Yihong black tea.

Tea hairs are an important indicator for evaluating the appearance quality of black tea. Currently, the evaluation mainly relies on the sensory assessment of professionals, which is highly subjective and abstract, lacking objective and digital quality evaluation methods. To construct a digital evaluation method for the quality of tea hairs, this study collected images of Qimen black tea samples with three different tea hairs quality grades. The HSV color image segmentation technique was used to extract the HSV color space component features of the region of interest (ROI), and a segmentation index (SI) was constructed to retrieve the optimal segmentation thresholds for tea hairs, tea body, and shadows. The image segmentation effect was qualitatively and quantitatively evaluated using the masking method and pixel point discrimination, and a quantification method for the proportion of tea hairs was established. The results show that the average segmentation accuracy of tea hairs, tea body, and shadow areas reached 98.70%. Furthermore, through the quantification of the proportion of tea hairs, the recommended hairs proportion thresholds for the three tea hairs quality grades of Qimen black tea (“Prominent golden hairs”, “Observable hairs”, and “Less hairs”) were obtained. The linear regression analysis of different hairs gradient blended tea samples (R²=0.958, P<0.01) and the generalization application effects on ‘Dianhong’ and ‘Jinjunmei’ indicate that the digital evaluation method of tea hairs quality constructed in this study has good adaptability in different hairs quantity intervals and different black tea categories.

Codon usage bias serves as a critical driving mechanism in gene expression regulation and molecular evolution, holding significant biological importance in the evolution of organelle genomes in plants. This study focused on the economically important tea cultivar ‘Baihaozao’ (Camellia sinensis cv. ‘Baihaozao’) and systematically analyzed the codon usage patterns and evolutionary drivers of its chloroplast (52 genes) and mitochondrial (29 genes) genomes for the first time. The results indicate: (1) the average effective codon number (ENC=44.57±4.59) of the chloroplast genome is significantly lower than that of the mitochondrial genome (ENC=51.87±5.31), with both exhibiting weak preference characteristics. Neutrality analysis reveals that the chloroplast's preference is primarily driven by natural selection (correlation between GC_3s and ENC, R² =-0.016), whereas the mitochondrial genome is regulated by a combination of natural selection and mutational pressure (R² = -0.11), which is consistent with the evolutionary constraints observed in the organelle genomes of dicotyledons. (2) RSCU analysis shows that both types of organelle genomes significantly prefer synonymous codons ending in A/U, with high-expression chloroplast genes (e.g., ndhA, rps14) exhibiting a stronger preference for A/U terminal codons. This suggests that translational selection optimizes highly expressed genes. (3) Through multivariate statistical screening, 18 optimal codons were identified for the chloroplast genome (e.g., GCA, GCU) and 18 optimal codons for the mitochondrial genome (e.g., GCA, AGA). GCA was favored in both organelle types, reflecting the adaptive convergence of functional genes across organelles. This study elucidated the heterogeneity of codon usage characteristics in the organelle genomes of ‘Baihaozao’ and their evolutionary drivers for the first time, providing a theoretical basis for the adaptive optimization of exogenous genes and the construction of cross-organelle expression regulatory networks in molecular tea breeding.

Processing techniques significantly alter the accumulation and composition of internal components in tea, forming different categories of tea products. Currently, there is limited research on the accumulation of compounds in different categories of Jingshan tea and their impact on taste quality characteristics. In this study, Jingshan green tea, matcha, and black tea were selected as the research object. The contents of physicochemical components such as water extracts, tea polyphenols, amino acids, and caffeine were detected, and the main compounds that constitute the taste and aroma skeleton of Jingshan tea were analyzed. The results show that the contents of compounds related to taste, such as water extracts, tea polyphenols, theanine, and glutamic acid, were significantly higher in green tea than in black tea. Meanwhile, black tea exhibited the highest accumulation of γ-aminobutyric acid. Jingshan green tea, matcha, and black tea were characterized by their “rich floral aroma and refreshing sweetness”, “fresh and thick”, and “sweet fruit aroma and lingering sweetness”, respectively. A total of 101 volatile compounds were identified in different categories of tea samples (31 in green tea, 30 in matcha, and 40 in black tea), among which cis-jasmone and 4,8-dimethyl-1,3,7-nonatriene are the key components contributing to the “elegant and floral” aroma quality of green tea. β-ionone, α-ionone, and β-cyclocitral are the essential components for the “fragrance” aroma of matcha. Geraniol and methyl salicylate are the crucial components for the “sweet aroma” of black tea. The research findings would be beneficial for expanding the study of Jingshan tea's flavor chemistry and provided a valuable reference for enhancing the high-quality processing of Jingshan tea.

Camellia sinensis var. pubilimba ‘Mayu’ is a dominant tea cultivar in Lüchun County, Yunnan. This study systematically analyzed the leaf anatomical structures and biochemical components of 28 germplasms using C. sinensis var. sinensis (CSS) and C. sinensis var. assamica (CSA) as controls. This study established a comprehensive evaluation system for germplasm resources for the first time. Key findings include: (1) M4 and M5 in the ‘Mayu’ tea group (MY) exhibits higher stomatal density than the controls, with a 30.0% and 10.6% reduction in stomatal area relative to CSS and CSA, respectively. The MY group exhibits unique undulated wax layers in the upper epidermis. (2) Cold resistance evaluation via membership function analysis identifies M4 and M5 germplasms with the highest scores (0.975 and 0.689), while the palisade-to-spongy tissue ratio shows a significant positive influence on the cold resistance (β=0.179, P<0.01). (3) Biochemical profiling reveals high stability in ‘Mayu’ tea’s water extracts (46.8%) and tea polyphenols (32.14%) (coefficient of variation, CV<5%). Its phenolic-to-amino acid ratio (9.05-14.54) indicates suitability for both black and green tea processing. The catechin quality index of ‘Mayu’ tea significantly surpassed controls (P<0.05), with bitter amino acids reduced by 18.04% compared to CSS and umami amino acids increased by 17.76% relative to CSA. While sweet amino acids show no significant inter-varietal differences. (4) Ten characteristic markers (including methionine, theanine, caffeine, and seven catechin derivatives) were identified through principal component analysis combined with differential metabolite screening, enabling discrimination of ‘Mayu’ tea from controls. This study elucidated the germplasm specificity of ‘Mayu’ tea from structural adaptation and biochemical perspectives, providing a theoretical foundation for its conservation, breeding, and functional component development.

Tea plants [Camellia sinensis (L.) O. Kuntze] is important leaf cash crops in China, and its growth and development are affected by plant hormones. As one of the six classical plant hormones, brassinosteroids (BRs) play crucial roles in regulating both developmental processes and stress adaptation in tea plants. Steroid 5α-reductase is a key enzyme in the brassinosteroid biosynthesis pathway. To characterize steroid 5α-reductase in Camellia sinensis, the CsDET2 gene was cloned from tea cultivar ‘Shuchazao'. Then, the physicochemical properties, secondary and tertiary structures, sequence characteristics, phylogenetic relationships, and subcellular localization of the encoded protein were analyzed, along with the cis-acting elements in gene promoter region. Furthermore, the expression profile of CsDET2 was examined across different organs under abiotic stress conditions and during a 12 h/12 h photoperiod cycle. The results reveal that the CsDET2 gene contains a 783 bp open reading frame encoding 260 amino acids. The CsDET2 protein has a molecular weight of 30 158.97 Da with a theoretical isoelectric point of 9.28, and is predominantly composed of α-helices and random coils, containing a characteristic steroid dehydrogenase domain. Comparative sequence alignment with DET2 proteins from 15 species shows 78.25% amino acid sequence identity. Phylogenetic analysis suggests that CsDET2 shares the closest evolutionary relationship with AfDET2 from Actinidiarufa. Subcellular localization experiments confirm that CsDET2 is localized in the cytoplasm. Analysis of cis-acting elements reveals that the promoter region of CsDET2 contains 4 types of photo-responsive elements, 4 types of stress-responsive elements, 3 types of hormone responsive elements, and 5 types of transcription factor binding sites. The fluorescence quantification results show that CsDET2 was expressed in all organs, and the expression level was the highest in the old leaves. In the 12L/12D photoperiod, the expression level of CsDET2 decreased first and then increased during the daytime, increased first and then decreased at night, and the expression level of CsDET2 at night was higher than that during the daytime. The expression of CsDET2 shows significant changes under high temperature and salt stress treatments, and was regulated by exogenous gibberellins. The results provided a theoretical basis and valuable insights for further exploring the function of tea plant steroid 5α-reductase.

Tea is a cash crop with large cultivated area in China, and its growth and development mechanism are strictly regulated by genes related to biological clock. In this study, the CsLUX gene was cloned using cDNA from tea cultivar ‘Longjing 43’ as template and sequence alignment and phylogenetic analysis were performed. Within two photoperiodic periods (48 h), the relative expression of CsLUX gene was detected by RT-qPCR, and photosynthetic parameters, stomatal opening and chlorophyll contents in tea leaves were also determined. The total length of CsLUX gene is 951 bp, encoding a hydrophilic protein composed of 316 amino acids. The secondary structure is mainly composed of α-helix and random curling. CsLUX is closely related to CCA1, ELF3 and other key components of the biological clock. The variation trend of photosynthetic parameters in tea leaves at different time points was basically consistent with stomatal opening, and the value of chlorophyll SPAD was basically stable. The relative expression of CsLUX reached its peak under dark conditions and maintained a low expression level during the day in response to changes in circadian rhythm. The expression of CsLUX gene was correlated with the rhythmic changes of photosynthetic parameters in two photoperiodic periods (48 h) in tea plants.

In this paper, an analytical method for the simultaneous determination of 20 phthalate esters in tea fresh leaves was developed by gas chromatography-tandem mass spectrometry (GC-MS/MS). The phthalate esters in tea fresh leaves were extracted by 0.1% acetonitrile acetate, salted out with sodium chloride, cleaned up with a florisil solid phase extraction column, resolved with acetonitrile, separated by temperature programmed chromatography, monitored with multiple reaction monitoring (MRM) mode, and quantified by the external standard method. Through the optimization of sample extraction, purification and chromatographic conditions, good linearity of the target compounds was obtained in the concentration range of 0.010-2.0 mg·kg^-1 with the corresponding coefficient of determination R²>0.995 5. The average recoveries ranged from 70% to 118% at the three spiked levels of 0.010 mg·kg^-1, 0.10 mg·kg^-1 and 1.0 mg·kg^-1, with the relative standard deviations (RSDs) of <17.8%. The limits of quantification were 0.010~0.050 mg·kg^-1. The method is stable and reliable, and it can meet the needs of the determination of phthalate acid esters in tea fresh leaves.

To explore the differences in tea leaf quality and metabolic profiles of a new seed-leaf dual-pupose tea cultivar ‘Jincha 1' under different cultivation patterns, the study investigated the phenological stages, lengths, weight per hundred buds of single bud, one bud with one leaf, and one bud with two leaves shoots under single plant sparse planting pattern and strip dense planting pattern. Moreover, comprehensive analyses were conducted on quality components and metabolomic profiling of the samples of one bud with two leaves. The results show that the tea cultivar ‘Jincha 1' under single plant sparse planting pattern yielded longer and heavier single buds, one bud with one leaf, and one bud with two leaves shoots compared to the strip dense planting pattern. Additionally, there is a delayed maturity period single plant sparse planting. Furthermore, the contents of tea polyphenols, catechins and gallic acid in the new shoots of single plant sparse planting pattern were 3.96, 5.06, and 1.19 percentage points higher than those of strip dense planting pattern, respectively. Conversely, strip dense planting resulted in higher total amino acid (1.27 percentage points) and theanine (0.21 percentage points) contents. A total of 163 significantly differential metabolites were identified by comparative metabolomics analysis, which were largely enriched in amino acid and polyphenol biosynthetic pathways. Notably, the contents of abscisic acid (ABA), gibberellin (GA), and jasmonic acid (JA) were higher in the single plant sparse planting pattern than those in the strip dense planting pattern. While, the levels of indoleacetic acid (IAA), 6-chloroadenosine phosphate (6-KT), and indole-3-butyric acid (IBA) in the single plant sparse planting pattern were lower than those in the strip dense planting pattern. This study reveals the mechanism by which different cultivation modes affect the tea quality through the regulation of endogenous hormones and metabolic pathways, providing a practical model for efficient cultivation in industrial promotion.

The color values of 865 colored tea germplasm were obtained by comparing them with the PANTONE and RHS plant color cards, and describing them in language. Based on the principles of color science and the descriptors and data standard for tea germplasm, the basis and method for leaf color identification and classification were established according to the coloring regularity of tea leaves. On the basis of the definition of leaf color, a framework of tea leaf color composition consisting of type, series, sub-series and color level was established. The existing tea leaf colors were drawn into a tea leaf color system diagram (leaf color wheel), including 5 types, 9 color series, 6 sub-series (belonging to 3 color series) and 72 color levels. This paper provided a scientific basis for the leaf color differentiation and accurate identification of colored tea germplasms.

Milled tea is the raw material for the production of matcha and it is the most important factor in ensuring the quality of matcha. Rapid and effective sorting of milled tea improves its quality. Due to the low efficiency and high labor intensity of the current sorting process in milled tea production, an online sorting system for milled tea was developed in this study. This system is composed of a material conveying system, an image acquisition system, an image recognition system, a positioning system and a sorting execution control system. The image acquisition system is used to collect the milled tea image and make the milled tea image data set. According to the real-time and lightweight requirements of milled tea recognition, the EfficientNet backbone network and SimSPPF module were introduced based on the YOLOv5s model, and the YOLOv5s-EfficientNet-SimSPPF model was improved and designed. On the basis of ensuring the recognition precision, the model recognition speed was improved and the model size was reduced. The established test set was used to evaluate the recognition performance of YOLOv5s, YOLOv5s-EfficientNet, YOLOv5s-SimSPPF and YOLOv5s-EfficientNet-SimSPPF on the PC. The recognition precision, recall, mAP@0.5, inference time and model size of YOLOv5s-EfficientNet-SimSPPF were 0.993, 0.981, 0.995, 6.3 ms and 2.85 MB, respectively. This study also proposed a sorting control algorithm for online sorting based on the online recognition results of milled tea. In addition, an auxiliary algorithm was proposed to prevent low-precision secondary recognition and secondary positioning of the milled tea on the boundary of the field of view of the industrial camera during the sorting process. The YOLOv5s-EfficientNet-SimSPPF model was deployed to the edge device Jetson Nano B01, and the model was tested using the test set. The recognition precision and speed were 0.982 ms and 37.5 ms, respectively. The results show that the real-time milled tea recognition can essentially be achieved by deploying the model migration to the developed online milled tea sorting system. Finally, the milled tea separation was carried out on the designed and developed platform, and the average separation accuracy rate of mixed milled tea leaves and milled tea stems reached 97.0%. The online milled tea sorting system proposed in this paper can meet the actual needs of online milled tea sorting, and can be used as an effective tool for the fine processing of matcha and milled tea sorting operation, providing a reference for online recognition and continuous sorting of other agricultural products.

Methylated catechins exhibit significant physiological activities, such as anti-allergy effects, and demonstrate stronger stability and higher oral absorption rate than unmethylated catechins. However, tea germplasms rich in methylated catechins are relatively rare. This study measured the EGCG3′′Me content in 447 tea germplasms from different regions with extensive genetic backgrounds, and two unique tea germplasms with high EGCG3′′Me content, namely ‘Jinxiu 2-2’ (JX) and ‘Pinming Tea’ (PM), were found. The tea germplasms JX, PM, and ‘Hongfugui’ (BFK) with high EGCG3′′Me content, as well as ‘Shuchazao’ (SCZ) with EGCG3′′Me content below the detection limit, were used as research materials. Relative expression levels of flavonol and anthocyanin O-methyltransferase (CsFAOMT1) in JX, PM, and BFK were significantly higher than that in SCZ. Further analysis reveals that four types of CsFAOMT1 alleles were cloned from the four tea germplasms, and all of them contain CsFAOMT1.3. Enzyme activity analysis at the protein level reveals that the CsFAOMT1 protein activities in the three tea germplasms with high EGCG3′′Me content all exhibit high activity with minimal differences between them. These results indicate that JX and PM can enrich EGCG3′′Me due to their high expression levels of CsFAOMT1. This study identified tea germplasm with high EGCG3′′Me content and elucidated the molecular mechanisms underlying its unique traits, providing important materials and theoretical basis for breeding new tea cultivars with high methylated catechin content.

Longjing tea appearance features are crucial for assessing tea quality. In order to intelligently evaluate the appearance characteristics of Longjing tea and quickly recognize the grades, a method combining image features and intelligent algorithms for appearance quality assessment was proposed. Images of the six grades of the standard Dafo Longjing tea were collected and their shape, color, and texture features were quantified and extracted to construct a database of tea appearance grade characteristics. The appearance features were fused and input into five machine learning models, namely, Decision Tree, Random Forest, K-Nearest Neighbor, Gaussian Bayesian, and Support Vector Machine, for grade recognition training. Three convolutional neural networks, VGG16, ResNet18 and DenseNet121 were compared to build a deep learning model for Longjing tea appearance evaluation. Then the model was optimized by optimizers and learning rate decay. The results show that the fusion of shape and texture data combined with Support Vector Machine was the optimal model for grade recognition, with an accuracy of 91.14% and an F₁ score of 91.20%. The ResNet18 network structure was chosen to establish the optimal model for appearance evaluation. After optimization by Adadelta optimizer and CosineAnnealingLR learning rate decay, the recognition accuracies of Longjing tea’s flatness, straightness, tenderness, and color all improved, reaching 99.21%, 99.51%, 99.56%, and 99.68%, respectively. This study provided a theoretical foundation for the digital evaluation of the appearance quality of tea.

Soil aggregate is an important indicator of soil structure and fertility. Soil compaction and nutrient deficiency in tea gardens in subtropical red soil areas seriously affect the stability of soil carbon pools. Evaluating the effects of biochar-based fertilizer application on the organic carbon structure characteristics and physical stability of soil aggregates in tea gardens can help to reduce soil barriers and improve productivity in intensive tea gardens. In this study, a 40-year old Xishan tea garden in Guiping, Guangxi, located along the Tropic of Cancer, was selected as the research object. Three treatments [biochar-based fertilizer (BF), chemical fertilizer (F), and no fertilizer (CK)] were used for a field positioning test for two consecutive years to explore the soil aggregate structure, organic carbon distribution and physical stability of the tea garden. The results show that: (1) the application of biochar-based fertilizer increased soil pH value and cation exchange capacity (C_EC), and tended to decrease soil bulk density (B_D). The soil pH value under the treatment of biochar-based fertilizer increased by 0.18 and 0.31 respectively compared with the no fertilizer and chemical fertilizer treatments. The soil bulk density under the biochar-based fertilizer treatment decreased by 4.52% compared with the chemical fertilizer treatment. The cation exchange capacity under the biochar-based fertilizer treatment increased by 12.12% and 15.09% respectively compared with the no fertilizer and chemical fertilizer treatments. (2) The application of biochar-based fertilizer improved the structural stability of soil aggregates and promoted the formation of large aggregates with soil water stability. The values of water stability large aggregates (R_W0.25), mean mass diameter (D_MW) and geometric mean diameter (D_GM) of aggregates >0.25 mm under the biochar-based fertilizer treatment were increased by 15.34%, 23.94% and 34.48% compared with the chemical fertilizer treatment. (3) The application of biochar-based fertilizer increased the organic carbon content of soil macroaggregates, which was conducive to the storage of organic carbon in soil macroaggregates. The organic carbon content of the aggregate with particle size >2.00 mm under the biochar-based fertilizer treatment was significantly higher than that under the chemical fertilizer and no fertilizer treatments, increasing by 45.23% and 17.28%, respectively. The contribution rate of organic carbon in biochar-based fertilizer was 77.48% and 13.11% higher than that of chemical fertilizer and no fertilizer, respectively. The contribution rate of active organic carbon in aggregates under biochar-based fertilizer treatment was 50.40% higher than that under chemical fertilizer treatment. (4) The application of biochar-based fertilizer improved the stability of organic carbon in microaggregates. For aggregates with a particle size of >0.053-0.25 mm and ≤0.053 mm, the organic carbon oxidation stability coefficient (K_OS) under biochar-based fertilizer treatment increased by 82.42% and 77.78%, respectively, compared with that under no fertilizer treatment. For aggregates with particle size of >0.25-2.00 mm, the organic carbon oxidation stability coefficient under biochar-based fertilizer treatment decreased by 40.79% and 49.58%, respectively, compared to the chemical fertilizer and no fertilizer treatments. Biochar-based fertilizer treatment had a tendency to reduce the stability of organic carbon in large soil aggregates. The application of biochar-based fertilizer is conducive to the optimized management and carbon pool stability of tea gardens.

The growing environment significantly influences the accumulation of chemical compounds in tea plants. However, systematic studies on the changes in chemical composition after translocating the tea cultivar ‘Huangshanzhong’ to the high-latitude Shandong region remain scarce. This study investigated the green tea samples of Camellia sinensis cv. Huangshanzhong from two regions: the native origin (YCD, Huangshan, Anhui) and a transplanted region (SD, Rizhao, Shandong). Differences in the content levels of the chemical components were analyzed. Additionally, widely-targeted metabolomics techniques were employed to identify differential metabolites and elucidate core metabolic pathways. The results demonstrate that SD samples exhibited significantly higher levels of water-soluble carbohydrates, total ash, water-soluble ash, water extract content and total galloylated catechins than YCD. While the total polyphenols and caffeine showed no inter-regional difference. SD accumulated more asparagine, glutamate, and arginine, whereas YCD was richer in flavor-related amino acids, such as theanine, GABA, lysine. Metabolomics analysis identified 116 differential metabolites (73 upregulated, 43 downregulated), with flavonoids exhibiting the highest abundance and diversity among them. KEGG enrichment analysis further revealed that the purine metabolism, phenylalanine metabolism, and pyrimidine metabolism pathways were the most significantly enriched pathways, contributing most to the differences between the SD and YCD samples. This study provided a systematic comparison of chemical components in green tea from cv. ‘Huangshanzhong’ after high-latitude transplantation versus the original cultivation, offering scientific insights into tea cultivar adaptation and flavor quality optimization.

This study aimed to elucidate the underlying mechanism by which roasting temperatures influence the flavor quality of Wuyi Rougui tea. Specifically, it sought to characterize the dynamic responses of biochemical components, antioxidant activity, and spectral features under varying thermal processing conditions. Wuyi Rougui tea leaves were processed at three roasting temperatures: (light roast 110 ℃, medium roast 125 ℃, high roast 140 ℃). A comprehensive analytical framework was implemented, integrating sensory evaluation, chromaticity analysis, ultra-high-performance liquid chromatography (UHPLC)-based quantification, and in vitro antioxidant capacity assessment. Fourier transform infrared spectroscopy (FTIR) coupled with chemometric modeling was employed. Raw spectral data were preprocessed to establish an orthogonal partial least squares-discriminant analysis (OPLS-DA) model for identifying characteristic wave numbers. Subsequent correlation analysis and partial least squares regression (PLSR) modeling reveal the relationships between spectral signatures and quality attributes (sensory parameters, chromaticity indices, biochemical constituents, and antioxidant activity). This ultimately identified the key compounds governing roasting-derived flavor profiles. The roasting temperature significantly modulated non-volatile metabolites and antioxidant capacity. Medium-fire-treated samples exhibited optimal sensory quality with a mellow taste profile. Elevated roasting temperatures progressively reduced tea polyphenols (TP), free amino acids (FAA), total flavonoids (TF), soluble total sugars (STS), catechin content, and DPPH radical scavenging capacity. The FTIR-OPLS-DA modeling (R²X=0.964, R²Y=0.991, Q²=0.981) identified two discriminative wave numbers: 1 018 cm^-1 (C-O-C vibration in carbohydrates) and 1 739 cm^-1 (The C=O bond of the ester is broken), which strongly correlated with taste attributes (|r|>0.69). The PLSR analysis further identified soluble sugars, FAA, ferulic acid, and chlorogenic acid as critical determinants of roasting flavor (R2 p>0.85). This study is the first to elucidate the synergistic interplay of soluble sugars, FAA, epicatechin derivatives (EGCG/EGC/EC), and phenolic acids (ferulic acid/CGA) in shaping the characteristic roasting quality of Wuyi Rougui tea. The findings established a theoretical foundation for precise roasting in Wuyi rock tea production and proposed a novel spectroscopy-guided quality control strategy.

In recent years, tea production in China has faced challenges of labor shortages, driving urgent industrial demands for mechanized harvesting technologies. The prevalent issues of high leaf fragmentation and low harvest quality in current mechanical systems are closely related to tea plant phenotypic traits. This study investigated seven widely cultivated tea cultivars mainly being suitable for black/oolong tea production in Guangdong Province. Phenotypic data from 100 quadrat sample plots of seven tea cultivars was systematically collected. Multiple analytical approaches, combined with mechanical harvesting quality predictive models, were employed to identify critical determining traits. The correlation analysis demonstrates that leaf length, leaf length-to-width ratio, length of one bud with two leaves, and length of one bud with three leaves were positively correlated with mechanical harvesting quality, whereas the total bud density showed a negative correlation. Grey relational analysis reveals significant associations between the mechanical harvesting quality and the leaf length-to-width ratio, leaf width, length of one bud with one leaf, and length of one bud with two leaves. Random forest analysis identifies the leaf length-to-width ratio, third internode length, and fourth internode length as critical traits influencing the superior harvest rate, intact rate, and fragmentation rate in mechanical harvesting, respectively. Further validation combined four phenotypic trait groups (full trait set, correlation-significant traits, grey relational>0.9, random forest top 6) with four machine learning algorithms to predict three core mechanical harvesting traits. The results demonstrate the grey relational traits achieved the optimal prediction for superior harvest rate (R²=0.65, RMSE=0.04), and random forest-selected traits were suitable for intact rate prediction (R²=0.86, RMSE=0.02), and complete trait group shows the highest fragmentation rate accuracy (R²=0.92, RMSE=0.01). Integrated modeling analysis identifies the length of one bud with two leaves and third internode length as key mechanical harvestable traits influencing black and oolong tea production. These findings established theoretical foundations and provided critical parameters for breeding tea cultivars optimized for mechanical harvesting.

Colletotrichum camelliae is the dominant pathogen causing tea anthracnose. This disease causes significant defoliation, which has a major impact on the following year's yield and results in great economic losses. Therefore, the early and timely detection of C. camelliae in tea leaves is of great significance for effective control of anthracnose in production. In this study, based on a loop-mediated isothermal amplification (LAMP) assay, a specific gene encoding a late embryogenesis abundant (LEA) domain protein from C. camelliae was selected for the design of LAMP primers. Three pairs of specific LAMP primers, including two outer primers, two inner primers, and two loop primers, were designed and selected. Subsequently, a LAMP assay for C. camelliae was established through specificity and sensitivity tests, and by detecting C. camelliae in artificially inoculated and infected tea leaves. The optimal reaction condition was determined to be at 65 ℃ for 30 min. The results were verified by 2% agarose gel electrophoresis with SYBR Green Ⅰ added. Specificity tests reveal that, only DNA extracted from C. camelliae isolates exhibited a positive amplification reaction. In sensitivity tests, the assay could detect genomic DNA templates of C. camelliae at a minimum concentration of 100 ag·µL^-1. The LAMP assay accurately detected C. camelliae in artificially inoculated diseased leaves and anthracnose-affected leaves of 18 tea germplasms in the field. In summary, the LAMP assay for detecting C. camelliae established in this study has the advantages of rapid, simple and high sensitivity, enabling the specific detection of C. camelliae and the quick diagnosis of tea anthracnose.

Qingzhuan tea is a regional iconic product of Hubei Province. This study used Hubei-specific, pile-fermented (unpressed) Qingzhuan tea as a sample to optimize the water and alkali extraction processes via response surface methodology. The study then compared the physicochemical properties of two tea polysaccharides (TPS) and clarified their emulsion stability and loading effect over 10 days of storage. The results show that the optimal conditions for water extraction were 60 ℃, 367 W of ultrasonic power, a solid-to-liquid ratio of 1:40 and an extraction rate of (5.019±0.130)%. The optimal conditions for alkali extraction from the water-extracted tea residue were 85 ℃, a solid-to-liquid ratio of 1:40, pH 9.0 and an extraction rate of (1.101±0.034)%. The molecular weight, free radical scavenging rate for antioxidant activity, monosaccharide content, particle size, zeta potential, emulsion stability and loading capacity of water extracted TPS were higher than those of alkali-extracted TPS. TPS emulsions show good stability during the storage period of 10 days, and has a broad application prospect as a load material.

The tea geometrid (Ectropis grisescens Warren) is the most destructive defoliator in tea gardens in China. In recent years, E. grisescens has developed medium to high level resistance against common pesticides. To address this challenge, six chemical pesticides and three biological pesticides were selected and comprehensively evaluated from four aspects: laboratory toxicity assays, field evaluation, safety assessment for natural enemies, and pesticide residue analysis in tea leaves. The results of laboratory toxicity assays indicate that matrine (LC₅₀: 3.54 mg·L^-1), spinetoram (LC₅₀: 4.12 mg·L^-1), and spinosad (LC₅₀: 9.68 mg·L^-1) exhibited potent contact toxicity against the 2^nd instar larvae. In the stomach toxicity tests, spinosad (LC₅₀: 0.01 mg·L^-1), matrin (LC₅₀: 0.10 mg·L^-1), spinetoram (LC₅₀: 0.31 mg·L^-1), methoxyfenozide (LC₅₀: 11.06 mg·L^-1), chlorfenapyr (LC₅₀: 38.80 mg·L^-1), and indoxacarb (LC₅₀: 49.87 mg·L^-1) exerted relatively optimal stomach toxic effects on the 2^nd instar larvae. The subsequent field efficacy trials reveal that spinetoram, chlorfenapyr, spinosad, and indoxacarb all showed remarkable control effects on E. grisescens larvae. Spinetoram achieved a control efficacy over 90% after 1 and 3 days of application, highlighting its rapid and remarkable properties. For the other three pesticides, their control efficacy surpassed 80% on the 7^th day, indicating ideal long-term effectiveness. The toxicity assessment of natural enemies indicates that the LC₅₀ values of spinetoram (LC₅₀: 5.39 mg·L^-1), and spinosad (LC₅₀: 39.75 mg·L^-1) for Arma chinensis were higher than those for the 2^nd instar larvae. This finding suggests that using spinetoram and spinosad to control E. grisescens in the field poses relatively low risks to natural enemies. Finally, the results of pesticide residue analysis shows that only indoxacarb remained at 0.30 mg·kg^-1 after 7 days of application, and no other pesticide treatments were detected, all of which met the maximum residue limit standards in China (GB 2763—2021). In conclusion, spinetoram and spinosad, characterized by their high efficiency and safety, were appropriate for rotational use to control the Ectropis grisescens.

During the growth and development of tea plants (Camellia sinensis), abiotic stresses such as drought and salinity frequently occur, causing significant adverse effects on tea yield and quality. This study focused on the tea phospholipid: diacylglycerol acyltransferase 1 (PDAT1) gene and systematically investigated its function in response to abiotic stresses through bioinformatics analysis, gene expression pattern detection, and transgenic functional verification. Bioinformatics analysis reveals that the protein encoded by the CsPDAT1 gene possesses a typical lysophospholipid acyltransferase (lysoPLA) domain. Real-time quantitative PCR (qRT-PCR) results demonstrats that the expression of the CsPDAT1 gene was significantly upregulated under drought and high-salt treatments, particularly during the early stages of drought stress. To further elucidate its function, researchers constructed an overexpression vector for the CsPDAT1 gene and transformed it into Arabidopsis thaliana. Finally three homozygous T3-generation transgenic lines were obtained. Phenotypic analysis reveals that under drought stress, Arabidopsis plants overexpressing the CsPDAT1 gene exhibited a significantly higher seed germination rate compared to that of wild-type plants, along with reduced malondialdehyde (MDA) content, increased proline content, and significantly enhanced antioxidant enzyme activity. This study confirmed that the CsPDAT1 gene in tea plants enhances plant tolerance to abiotic stress by regulating cell membrane lipid metabolism and the accumulation of osmoprotectants, providing a theoretical foundation and genetic resources for stress-resistant molecular breeding in tea plants.

The seeds of ancient tea plants represent valuable natural genetic resources and gene pools, playing a crucial role in enriching tea plant genetic resources and maintaining genetic diversity. To investigate their characteristics, this study utilized seeds from 8 ancient tea plants (designated TZ-1 to TZ-8) and a locally cultivated tea plant (TZ-9) in Tongzi County, Guizhou Province, China. We systematically compared their biological properties, including morphology, 100-grain weight, water absorption rate, bulk density, germination rate, and tea saponin content. Additionally, we analyzed the endophytic bacterial diversity using high-throughput sequencing. The results reveal significant variations in the biological properties among the ancient tea seeds. Specifically, TZ-3 exhibited the highest 100-grain weight (269.52 g), while TZ-1 had the smallest values in these traits. The cultivated variety TZ-9 has the highest relative water absorption rate (32%) and germination rate (85%). Among the ancient tea plants, TZ-6 had the highest germination rate (76%), and TZ-2 had the lowest (11.67%). The tea saponin content varied from 21.00% to 49.91% among the ancient tea plants, with TZ-3 and TZ-4 exceeding 40%. The analysis of endophytic bacteria detects a total of 1 141 OTUs, covering 26 bacterial phyla. Among them, the richness of the TZ-3 community was the highest (OTU=185), and TZ-2 was the lowest (OTU=46). PCoA/NMDS analysis shows that the community structures of TZ-2, TZ-3, and TZ-8 were significantly separated, and this separation was independent of the ecological type (ancient/cultivated plants). Correlation analysis revealed that the abundance of genera such as Planctomycetota and Firmicutes was positively correlated with seed diameter, 100-grain weight, and tea saponin content (P<0.05), while Desulfobacterota and Bacteroidota were negatively correlated with water absorption rate. This study initially elucidated the association between the biological characteristics of ancient tea seeds and their endophytic bacterial communities, offering a theoretical foundation for the conservation and innovative utilization of tea germplasm resources.

Tea gray blight is one of the major foliar diseases in tea plantations, significantly affecting both yield and quality. In July 2023, tea leaves exhibiting resembling gray blight symptoms were observed during a filed surver in tea plantations in Mengla County, Xishuangbanna Dai Autonomous Prefecture, Yunnan Province. As the causal pathogen of these symptoms had not been previously reported in this region, this study aimed to identify the causal agent and its taxonomic classification. The pathogen was successfully isolated and identified using a combination of tissue isolation, pathogenicity testing via wound inoculation, morphological characterization, and molecular phylogenetic analysis based on ITS and TUB genes squences. The results confirmed that the strain FN3-2, isolated from symptomatic leaves, was pathogenic. Based on morphological traits and molecular evidence, the pathogen was finally identified as Neopestalotiopsis protearum. The finding provided a scientific basis for the accurate disease diagnosis and biocontrol agent screening, contributing to the sustainable development of tea production in the region.

The indoor efficacy of eight chemical pesticides and six biological pesticides against Basilepta melanopus adult was evaluated using the leaf-dipping method. Field control efficacy trials were conducted to screen the pesticides for controlling B. melanopus adult, and the residues of these pesticides in dry tea were measured seven days after application. The results show that in the indoor efficacy test, 72 h after I-cyhalothrin (effective component 16.5 mg·L^-1), bifenthrin (effective component 55.6 mg·L^-1), chlorfenapyr (effective component 143 mg·L^-1), thiacloprid (effective component 124 mg·L^-1), tolfenpyrad (effective component 165 mg·L^-1), pyriproxyfen-chlorfenapyr (effective component 165 mg·L^-1) and natural pyrethrum (effective component 52.8 mg·L^-1) had higher lethality to the adult of B. melanopus, with lethality rates of 100%, 100%, 100%, 100%, 100%, 95% and 80%, respectively. Next were pyriproxyfen (effective component 1 480 mg·L^-1) and azadirachtin (effective component 16.5 mg·L^-1), with the lethality rates of 50% and 28%. The lethality rates of buprofezin, Empedobacter brevis, tea saponin, cineole, Metarhizium anisopliae CQMa421 were not significantly different from the clear water control. The maximum control efficacies of I-cyhalothrin (effective component 16.88 g·hm^-2), bifenthrin (effective component 56.25 g·hm^-2), chlorfenapyr (effective component 201 g·hm^-2), and natural pyrethrum (effective component 36 g·hm^-2) against B. melanopus adult after field application for 1~7 d were up to 100%, 100%, 93.99% and 40.82%, respectively. After 7 days of pesticide application, the residues of bifenthrin and chlorfenapyr were both lower than the maximum residue limits (MRL) in national standard (GB 2763—2021) and EU standard for pesticides in tea. Whereas the residue of I-cyhalothrin was only lower than the MRL in GB 2763—2021. Although the field control efficacy of thiacloprid (effective component 126 g·hm^-2) could be 98.31%, the residue in dry tea produced 7 days after application exceeded the MRLs in both GB 2763—2021 and EU standards. In conclusion, bifenthrin, chlorfenapyr, I-cyhalothrin and natural pyrethrum can be selected as needed for the control of B. melanopus adult in tea plantations.

Low temperature stress significantly impairs the growth and development of tea plants (Camellia sinensis), as well as the yield and quality of tea. The WCOR413 gene family plays an important role in plant cold resistance. However, it has not yet been systematically identified in tea plants. This study employed pan-genome and cold acclimation transcriptome data of tea plants, combined with bioinformatics and RT-qPCR analysis, to identify members of the CsWCOR413 gene family. The results show that the CsWCOR413 family consists of six members (CsWCOR413-1 to CsWCOR413-6), which can be divided into two subclasses based on the conserved domains of the proteins: plasma membrane-localized and internal/thylakoid membrane-localized. Promoter cis-element analysis finds that the CsWCOR413 genes may be regulated by various transcription factors, enabling them to respond to cold, dehydration and ABA signals. RT-qPCR analysis reveals the expression patterns of the CsWCOR413 genes. CsWCOR413-1 was predominantly expressed in leaves, responded to JA and ABA signaling, and was significantly induced by low temperature stress. CsWCOR413-5 responded to short-term cold stress and calcium ion signaling. The transcriptome and Weighted gene co-expression network analysis (WGCNA) indicate that CsWCOR413-1 was significantly upregulated during natural cold acclimation and was strongly co-expressed with CsCBF3, a core transcription factor in cold signaling. Subcellular localization reveals that CsWCOR413-1 was localized in the cell membrane and cytoplasm. Dual-luciferase reporter assay confirms that CsCBF1 and CsCBF3 directly bound to the CsWCOR413-1 promoter and activated its expression. This study systematically elucidated the characteristics and expression profiles of the CsWCOR413 gene family and revealed that CsWCOR413-1 is transcriptionally regulated by CsCBF1 and CsCBF3, suggesting the crucial role of CsWCOR413-1 in tea plant under low temperature stress.

Tea anthracnose is a major disease that affects large-leaf tea plants. Severe infections can significantly reduce yield and compromise quality. Leaves showing symptoms of anthracnose were collected from tea plantations in Shahe Township, Lincang City, Yunnan Province. The pathogen was isolated and purified using conventional tissue separation methods. It was identified as the causal agent by fulfilling Koch's postulates, and further confirmed through morphological characterization and multi-gene phylogenetic analysis. The results show that the isolated strain MTTJ-Ⅴ could infect tea plants and cause identical anthracnose symptoms. Based on morphological characteristics and a multi-locus phylogenetic analysis of the ITS, TUB2, ACT and GAPDH gene sequences, the pathogen was identified as Colletotrichum karstii. This is the first report of C. karstii as a pathogen of tea anthracnose on Yunnan large-leaf tea plants. A total of 161 endophytic bacterial strains were isolated from the stems and leaves of 11 tea cultivars. Among these, 59 strains exhibited significant antagonistic activity against C. karstii. Strain CGJ-02 showed the highest inhibition rate (73.73%±6.25%). Based on morphological, physiological, biochemical and molecular biological characteristics, strain CGJ-02 was identified as Bacillus velezensis. Strain CGJ-02 exhibited a broad antifungal spectrum, showing antagonistic effects against 11 pathogenic fungi, including Colletotrichum camelliae and Pestalotiopsis camelliae, in addition to C. karstii. In conclusion, the screened strain B. velezensis CGJ-02 demonstrated significant biocontrol activity against the tea anthracnose pathogen MTTJ-Ⅴ. This strain represents a high-quality microbial resource for the biological control of tea anthracnose.