Animals cannot synthesize branched-chain amino acids (BCAAs) endogenously and must obtain BCAAs from the diet. The BCAAs content in crops becomes a key nutritional indicator. Branched-chain aminotransferase (BCAT) is the sole enzyme responsible for both the biosynthesis and catabolism of BCAAs, positioning it as a pivotal regulatory hub in BCAA metabolism. Using the cassava cultivar SC205, we integrated metabolomic and transcriptomic datasets to identify MeBCAT1 and MeBCAT3 as key genes involved in BCAA metabolic pathways. Bioinformatic characterization and quantitative real-time PCR were employed to profile the tissue-specific expression patterns of the genes, and the subcellular localization was examined using a transient expression system in Nicotiana benthamiana leaf epidermal cells. Both crude protein content and BCAAs abundance were significantly higher in cassava leaves than in tuberous roots. The cassava BCAT gene family consisted of eight members unevenly distributed across five chromosomes. Physicochemical analysis revealed that the encoded polypeptides ranged from 387 to 1,000 amino acids in length, with predicted isoelectric points (pI) ranging from 5.56 to 8.96. Synteny analysis indicated that segmental duplication events served as the predominant driving force underlying the expansion of the cassava BCAT gene family. Further transcriptomic evaluation uncovered substantial divergence in the transcriptional abundance of MeBCAT1 and MeBCAT3, both genes exhibited pronounced expression in foliar tissues, with MeBCAT1 showing particularly high transcript levels. MeBCAT1 and MeBCAT3 encoded polypeptides of 387 and 450 amino acid residues, respectively, and subcellular localization assays confirmed that both proteins were localized in the mitochondria. Together, our findings show that cassava leaves are a rich source of essential BCAAs for animal development and MeBCAT1 is a key genetic regulator of BCAA metabolism. This study thus would offer a theoretical framework for enhancing cassava’s nutritional quality as a feed crop and establishes a foundation for dissecting the molecular mechanisms of BCAA metabolism in this staple crop.

MYB transcription factors play crucial roles in plant growth and development, secondary metabolism, and responses to environmental stresses. In this study, a 1R-MYB transcription factor gene, MeMYBS1, was cloned from cassava (Manihot esculenta Crantz) cultivar South China 8 (SC8) using RT-PCR technology. Bioinformatics analysis using online tools such as ExPasy and NCBI-CDD revealed that the full-length of MeMYBS1 was 1008 bp, encoding a protein of 335 amino acids with a predicted molecular weight of 36.3 kDa and an isoelectric point of 6.46. Subcellular localization analysis via PEG-mediated transient expression in cassava protoplasts demonstrated that MeMYBS1 was localized in the nucleus. qRT-PCR tissue expression analysis showed that MeMYBS1 exhibited high expression abundance in cassava storage roots. Furthermore, during the process of post-harvest physiological deterioration (PPD) in South China 9 (SC9) storage roots, the expression level of MeMYBS1 showed a significant downward trend as storage time extended. The results preliminarily characterized the expression patterns of MeMYBS1 during cassava PPD, providing a theoretical foundation for further elucidating the molecular mechanisms by which this gene regulates PPD in cassava.

Peppers are an important vegetable and cash crop in China. Leaf color mutants serve as valuable materials for studying plant photosynthesis, pigment metabolism, and stress response mechanisms. In this study, the albino mutant CA123 (paternal) of Capsicum annuum was crossed with the green-leaf inbred line CaY6 (maternal) to generate an F₂ segregating population. Using integrated multi-omics approaches, including bulked segregant RNA-Seq (BSR-Seq), transcriptome (RNA-Seq) and metabolomics analysis, we elucidated the genetic mechanism of leaf albinism in peppers. BSR-Seq analysis localized key genes controlling the albino trait to two regions on pepper chromosome 12. Within the two loci, 90 functional mutations were detected, and five candidate genes were identified: ZLC12G0008580 (CLC-A), ZLC12G0018770 (CYP71AU50), ZLC12G0017660 (PCMP-H81), ZLC12G0009880 (PCMP-E26), and ZLC12G0018520 (FBN5). The comparative transcriptome analysis identified numerous differentially expressed genes (DEGs). KEGG enrichment analysis indicated that these genes were significantly enriched in diverse pathways, including MAPK signaling-plant, glutathione metabolism, photosynthesis-antenna proteins, Calvin cycle, and brassinosteroid biosynthesis. Significant expression changes were observed in multiple key genes, including receptor kinases (XA21), transcription factors (WRKY24), and enzymes such as peroxidases and glutathione S-transferases. Metabolomics analysis identified hundreds of differentially expressed metabolites, primarily enriched in pathways such as glyoxylate and dicarboxylic acid metabolism, alkaloid biosynthesis, and ABC transporters. Metabolites such as citric acid, linolenic acid, jasmonic acid, and malic acid exhibited significantly altered levels in albino leaves. WGCNA analysis revealed that the antique white 4 module was significantly correlated with the albino phenotype, from which multiple hub genes, including transcription factors PBF1, HY5, MOF1, and BBX22, were identified. In summary, this study analyzed the characteristics associated with leaf bleaching in peppers from three perspectives: genetic mapping, transcriptional regulation, and metabolomics. It provides an important reference for understanding the patterns of leaf color variation in peppers and lays the foundation for the further development of molecular markers for leaf color in peppers to aid in breeding.

Peanut (Arachis hypogaea L.) is an important oil seed and cash crop in China. This study aimed to identify major QTLs for sucrose and oil quality traits to provide theoretical support for molecular breeding. A recombinant inbred line (RIL) population derived from the cross ZLA×DB was used as research material. Phenotypic data for sucrose content, oil content, and fatty acid composition were collected under four environments. A high-density genetic map containing 3415 SNP markers was constructed, and QTL mapping for sucrose content, oil content and fatty acid components was performed using the composite interval mapping method. A total of 25 QTLs were detected on 11 chromosomes, with LOD values ranging from 2.7223 to 10.8423 and phenotypic variation explained (PVE) from 5.8933% to 21.5984%. Notably, within the 88.96-101.85 Mb interval on the distal end of chromosome A05, major QTLs for arachidic acid (qEA_A05.2, PVE=21.5984%) and stearic acid (qSA_A05, PVE=17.1650%) were co-localized, showing highly overlapping genetic confidence intervals and positive additive effects. This co-localization was consistent with the extremely significant positive correlation between the two traits in the population (r=0.860^***). This QTL co-localization region would provide genetic evidence for the carbon chain elongation from C18:0 to C20:0 in peanut and be hypothesized to contain a pleiotropic or tightly linked regulatory locus, serving as a core genetic region controlling very-long-chain saturated fatty acid synthesis. Additionally, two QTLs for sucrose content (qSC_A06 and qSC_A07) were detected on chromosomes A06 and A07, among which qSC_A07 is a newly identified regulatory locus. QTLs for oil content (qOC_A07, PVE=16.1874%), palmitic acid, and behenic acid were also mapped on multiple chromosomes. This study systematically revealed the phenotypic associations and genetic basis underlying sucrose content, oil content, and fatty acid components in peanut kernels, confirming that oil content and fatty acid composition are relatively independently regulated, whereas stearic acid and arachidic acid share a highly coordinated genetic mechanism. The results would provide important theoretical basis and candidate loci for key gene discovery and marker-assisted breeding for peanut quality traits.

Sugarcane variety Yunzhe 05-51 was used as the parent and crossed with 45 elite domestic and international parental lines, resulting in a total of 48 cross combinations. Employing the family evaluation method, a systematic investigation was conducted on nine traits in the sexual hybrid progeny, including cane yield, sugar yield, plant height, stalk diameter, number of millable stalks, and brix. The analyses encompassed variance analysis, heritability estimation, general and specific combining ability determinations, and cluster analysis. The 48 combinations exhibited rich genetic diversity in the traits. Among these, the coefficients of variation for yield-related traits such as cluster mass, brix mass, cane yield, and sugar yield all exceeded 30.00%, demonstrating substantial selection potential. In contrast, brix, a sugar-related trait, showed the lowest coefficient of variation (8.50%), indicating stronger genetic control and higher stability. For the tested sugarcane parental materials, significant or extremely significant differences (P<0.05 or P<0.01) were observed among male parents, female parents, and combinations for six major traits including plant height, stalk diameter, brix, number of millable stalks per cluster, single stalk mass, and brix mass. The contribution of parents and the selected combinations to the heritability of major traits in the progeny populations was ranked as follows: combinations (73.30%)>male parents (56.04%)>female parents (48.22%). Plant height and stalk diameter exhibited superior performance, with heritability exceeding 55.00% for the combinations, male parents, and female parents. Among the 48 tested sugarcane parental combinations, the elite male parents were identified including Yuetang 91-976, Yunrui 05-292, Yunrui 19-001, and Yunrui 08-1609. The elite female parents included Yunzhe 05-51, Yunrui 13-38, Yunrui 10-456, Yunrui 14-199, and Yunrui 09-315. The combinations such as Yunrui 09-315×Yunzhe 05-51, Yunrui 14-199×Yunzhe 05-51, Yunzhe 05-51×Yuetang 91-976, Yunzhe 05-51×Yunrui 05-292, and Yunzhe 05-51×Yunrui 08-1609 exhibited outstanding performance in the nine traits, combining high yield and high sugar characteristics, making them ideal combinations for sugarcane breeding. This study identified a number of high-quality parents and superior combinations, which would provide a theoretical reference and germplasm foundation for sugarcane breeding for high yield and high sugar content.

Phalaenopsis-type Dendrobium hybrids (Den-Phals) are important tropical ornamental plants, and establishing an efficient and stable genetic transformation system is crucial for gene functional research and molecular breeding. This study aimed to optimize selection conditions for genetic transformation and evaluate the transformation efficiency of different Agrobacterium rhizogenes strains. Using D. Noble Woman and D. Sonia Hiasakul as materials, the effects of different concentrations of L-methionine sulfoximine (MSO) on the growth of embryogenic calli (ECs), protocorms, calli and protocorm-like bodies (PLBs) were tested to determine optimal selection concentrations. The transformation efficiencies of three A. rhizogenes strains (K599, ATCC15834, and MSU440) on four explant types of both cultivars were compared and verified through GUS staining and bar gene PCR detection. Results showed significant differences in MSO sensitivity among different explants. The complete lethal concentration for Noble Woman ECs and protocorms was 20 μmol/L and 15 μmol/L, respectively, and that for Sonia Hiasakul PLBs and callus tissues was 8 μmol/L and 10 μmol/L, respectively. The optimized selection pressure effectively reduced false positive rates. Regarding transformation efficiency, strains ATCC15834 and MSU440 showed significantly higher transformation efficiency than K599 on most explants, with ATCC15834 achieving 7.45% positive rate for Noble Woman ECs and MSU440 reaching 8.42% for Sonia Hiasakul callus tissues. This study clarified applicable MSO concentrations for different explants of two Den-Phals and identified ATCC15834 and MSU440 as suitable A. rhizogenes strains for Den-Phals transformation, providing technical references for further optimization of genetic transformation systems and molecular breeding applications.

A new fresh-eating purple sweet potato cultivar, Guishu No.18, was developed via open pollination using Guiziweishu No.1 as the female parent, aiming to breed varieties with high yield, good eating quality, and high anthocyanin content. Based on the data from multi-location trials conducted in Guangxi and the southern sweet potato region during 2021—2022, its yield performance, stability, and adaptability were evaluated by combined analysis of variance and GGE biplot analysis, together with quality traits and disease resistance. The two-year average fresh storage root yield of Guishu No.18 was 27.99 t/hm² in the Guangxi multi-location trials, which was 9.69% higher than that of the control cultivar Guishu No.2. In the multi-location trials of the southern sweet potato region, the two-year average fresh storage root yield was 34.40 t/hm², representing a 37.38% increase over Ningzishu No.1, and ranking among the top tested cultivars. Combined analysis of variance indicated that year, location, genotype, and the interactions had significant effects on fresh storage root yield. GGE biplot analysis showed that Guishu No.18 had a relatively high mean yield, good stability, and wide ecological adaptability. The anthocyanin content of the storage roots was 456.10 mg/kg, with relatively high starch content and good fresh-eating quality. Disease resistance evaluation indicated that this cultivar was moderately resistant to type II sweet potato wilt. In conclusion, Guishu No.18 is a fresh-eating purple sweet potato cultivar with desirable comprehensive traits and good potential for demonstration and extension.

Planting materials constitute the material basis for ensuring high and stable yield of rubber plantations. The selection of high-quality planting materials can effectively shorten the tapping commencement period, increase the number of productive tapping trees, and thereby improve the overall yield of rubber plantations. To explore the effects of different planting materials on the early yield and latex physiological characteristics of rubber trees, three seedling types of the rubber tree cultivar Reyan 73397, namely juvenile scion budded seedlings, mature scion budded seedlings, and self-rooted clonal seedlings, were used as experimental materials. Under a randomized block design, the dry rubber yield in the 1st to 5th tapping years was systematically determined, and physiological indices including initial latex flow rate, plugging index, latex sucrose (SUC), inorganic phosphorus (Pi), thiol (RSH) and total solid content (TSC) were measured during the 1st to 3rd tapping years. The results showed that: (1) The average dry rubber yield over 1-5 tapping years followed the order: juvenile seedlings (644.40 kg/hm²)>mature seedlings (554.41 kg/hm²)>self-rooted seedlings (481.10 kg/hm²), and the yield of juvenile seedlings was significantly higher than that of self-rooted seedlings (P<0.05); (2) There were no significant differences in initial latex flow rate and plugging index among different materials, indicating that latex flow characteristics within the same cultivar were little affected by the type of planting material; 3) The contents of latex inorganic phosphorus and sucrose were the highest in juvenile seedlings, which were significantly higher than those of self-rooted seedlings and mature seedlings (P<0.05). Juvenile budded seedlings presented better substance and energy metabolism levels in terms of thiol and total solid content, and their early rubber yield performance was remarkably superior to self-rooted seedlings. Therefore, juvenile budded seedlings are recommended as the preferred choice for rubber plantation establishment in production.

The color transition of young mango leaves from reddish-brown to green is a critical developmental shift from heterotrophic sink organs to autotrophic source organs, which fundamentally determines photosynthetic efficiency and whole-plant nutrient accumulation. Previous studies have mainly focused on the effects of macro-element compound fertilizers on mango fruit yield and quality. In contrast, little is known about the regulatory effects and metabolic mechanisms of combined magnesium (Mg), iron (Fe), nitrogen (N), and phosphorus (P) fertilization on the leaf color transition process. This study aimed to investigate these regulatory effects and metabolic mechanisms using the mid-season mango cultivar ‘Palayinda’ (Mangifera indica L.) as the experimental material. A combined Mg-Fe-N-P fertilization treatment (T) was established, consisting of foliar application of magnesium sulfate (0.4 g/plant) and EDDHA-Fe (1.67 g/plant), root application of calcium phosphate (7.14 g/plant), and soil application of urea (3.26 g/plant), while the control (CK) received an equal volume of clear water. Leaf color parameters (L^*, a^*, and b^*) and photosynthetic pigment contents (chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids) were measured at five growth stages (August 21, 26, 31, September 5, and 10, 2024). Non-targeted metabolomics analysis was performed on three stages that exhibited significant differences between T and CK (August 26, August 31, and September 5). The results showed that fertilization significantly increased photosynthetic pigment contents at all stages, with peak values observed on September 5. Compared with CK, the T group exhibited increases of 56.65% in chlorophyll a, 88.77% in chlorophyll b, 65.76% in total chlorophyll, and 63.58% in carotenoids. Fertilization accelerated the greening process of young leaves, as reflected by significantly lower a^* values (redness, P<0.01) and significantly higher b^* values (yellowness, P<0.05) and L^* values (brightness, P<0.05) in the T group than in the CK group. Metabolomics analysis identified a total of 1704 metabolites, of which 558 were differentially accumulated between T and CK (P≤0.05, VIP>1). These differential metabolites were mainly enriched in pathways related to carbon fixation in photosynthetic organisms, starch and sucrose metabolism, the tricarboxylic acid (TCA) cycle, and amino acid biosynthesis. Among them, carbon metabolites such as sucrose, maltose, and trehalose were significantly up-regulated, whereas pyruvate and malate were significantly down-regulated. Nitrogen metabolites, including glutamate, γ-aminobutyric acid (GABA), arginine, proline, and alanine, were significantly up-regulated. Together, these results indicate that the combined Mg-Fe-N-P fertilization strategy synergistically regulates core pathways of carbon and nitrogen metabolism. It enhances photosynthetic carbon fixation efficiency, promotes the accumulation of non-structural carbohydrates (e.g., sucrose and maltose), and thereby provides energy and carbon skeletons for nitrogen metabolism. It also stimulates nitrogen assimilation and amino acid biosynthesis, increasing the levels of glutamate, arginine, proline, and other amino acids, which supply nitrogenous precursors for chlorophyll synthesis and photosynthetic enzyme systems. These processes accelerate the rapid color transition and photosynthetic maturation of young leaves. This study provides a theoretical basis and technical support for precision fertilization during the young leaf color transition stage in mango production.

Potassium chlorate is a key agent for inducing off-season flowering in longan (Dimocarpus longan Lour.), and its strong oxidizing property can cause oxidative stress in trees. Reactive oxygen species (e.g., H₂O₂) and reactive nitrogen species (e.g., NO), as key signaling molecules of oxidative stress, and their distribution and accumulation in terminal buds and leaves may regulate the flower bud differentiation process of off-season longan. In this study, 9-year-old 'Chuliang' longan trees were used as materials. Potassium chlorate was applied to the soil for flower induction, combined with foliar spraying of H₂O₂ generator (methyl viologen, MV), H₂O₂ scavenger (dimethylthiourea, DMTU), NO generator (sodium nitroprusside, SNP) and NO synthase inhibitor (L-NNA). The content changes and tissue distribution characteristics of H₂O₂ and NO in terminal buds and leaves during flower bud differentiation were systematically analyzed. The MV and SNP treatments significantly advanced the flower bud differentiation process of off-season longan, and the pure flower bud rate was significantly higher than that of the control at 28 days after treatment. DMTU and L-NNA treatments inhibited or slowed down the flowering process. H₂O₂ was mainly distributed in the apical meristem and rudimentary leaves of terminal buds, and first accumulated in the main veins of leaves and then diffused to the mesophyll. The peak of H₂O₂ in leaves appeared earlier than that in terminal buds. SNP and MV treatments could enhance the fluorescence intensity of H₂O₂, while DMTU treatment significantly scavenged H₂O₂. The NO content reached a peak at 7 days after flower induction, SNP treatment could significantly increase the NO content in terminal buds and leaves, and L-NNA treatment had no significant effect on NO accumulation but inhibited flowering. In conclusion, H₂O₂ and NO, key signaling molecules, jointly promote the flowering of off-season longan. The content changes and tissue distribution characteristics would provide a theoretical basis for analyzing the oxidative stress mechanism of potassium chlorate-induced longan flower bud differentiation.

Date palm (Phoenix dactylifera L.) is a distinctive economic tree species widely cultivated in arid and semi-arid regions, particularly across the Middle East and North Africa. Its significance as a staple food source, often referred to as "bread of the desert," combined with its environmental role as an ecological pioneer in desertification control, solidifies its vital position within tropical agricultural economies. Against the backdrop of global warming and increasing water scarcity for agricultural irrigation, drought has emerged as a key limiting factor affecting the growth, development, and productivity of date palms, posing a significant constraint to the sustainable development of the date palm industry. This review synthesized the impacts of drought stress on the vegetative growth, yield, and quality of date palms. It elaborated on the physiological responses of date palms to drought, encompassing alterations in photosynthetic characteristics, osmotic regulation, antioxidant defense systems, and endogenous hormone regulation. Furthermore, the paper outlined key molecular pathways involved in drought adaptation, including osmotic adjustment, oxidative stress defense, cell structure protection, and hormone signaling, along with the expression of drought-related genes and the application of omics technologies in elucidating molecular mechanisms of drought resistance. Additionally, strategies and approaches to enhance drought tolerance in date palms were summarized, covering agronomic and management practices, microbial-assisted methods, and advancements in genetic improvement and biotechnology. This review aims to provide a theoretical foundation and practical references for further research into drought tolerance mechanisms and the development of drought-resistant date palm cultivars.

The purpose of this paper was to investigate the effects of different types of fruit bagging treatments on the fruitlet microenvironment and fruit quality formation of Dongshizao pomelo, and to provide a theoretical basis for the rational selection of bag types in production. Dongshizao pomelo cultivar was used as the experimental material. The effects of no bagging (CK) and 4 types of fruit bags on microenvironment indices including temperature, relative humidity, photosynthetically active radiation intensity, and the content of pigments in fruit peels, soluble sugar, soluble solids, total acid, and other fruit quality indices were explored during fruit development. The 4 types of bags were white-single-layer paper bag (BD), white nonwoven bag (WF), single-layer paper bag with yellow outside and black inside (HD), and double-layer paper bag with yellow outside and black inside (HS). The daily variations in temperature and relative humidity under bagging were generally consistent with the external environment, which exhibited a dynamic regulation where an increase in temperature was accompanied by a decrease in relative humidity. The microenvironment of fruit growth and development was changed by bagging with different bag types, creating a space characterized by high temperature, low humidity, and weak light. Among the treatments, the maximum temperature and the temperature difference for the HD and HS bagging treatments were significantly higher than those for the CK and BD bagging treatments. Furthermore, the HD and HS treatments resulted in a significantly lower average humidity and a photosynthetically active radiation of 0 µmol/(m²·s), significantly promoted the degradation of chlorophyll and carotenoids in the peel of chlorophyll and carotenoids in the peel. The application of bagging treatments significantly influenced the accumulation pattern and concentration of soluble sugar in the fruit peel, with the peel sugar content at fruit mature period being significantly higher than CK at the fruit mature period being significantly higher than CK. For the pulp, however, bagging treatments significantly affected the sugar content without changing its overall accumulation trend. During fruit growth and development, bagging treatments resulted in no significant difference in the total soluble solids content of the pulp compared to the CK. However, bagging significantly influenced both the accumulation trend and the content of total acid in the pulp. At harvest, the WF bagging treatment resulted in the highest soluble sugar content (2.82%), which was significantly higher than that of the control and HS treatment. However, the HS treatment resulted in the lowest total acid content, and the solid-acid ratio (20.83) was significantly higher than the control and all other treatments was significantly higher than the control and all other treatments. To sum up, bagging altered the microenvironment of temperature, humidity, and light conditions around the fruit, and systematically regulated peel pigment metabolism and sugar-acid accumulation, ultimately influenced the comprehensive fruit quality the comprehensive fruit quality of Dongshizao pomelo. The double-layer paper bag with yellow outside and black inside effectively reduced fruit acidity and improved the solid-acid ratio, whereas the white nonwoven bag promoted soluble sugar accumulation. Therefore, the choice of bag type in production should be determined by the desired fruit quality attributes.

Fusarium oxysporum f. sp. cubense race 4 (Foc4) is one of the primary pathogens causing banana Fusarium wilt, a devastating soil-borne disease that hinders the green and sustainable development of the global banana industry. As core carriers for biological control, antagonistic bacteria exhibit broad-spectrum antimicrobial activity. In this study, two antagonistic strains, 9ZJF-4 and 6ZJF-5, isolated from the rhizosphere of healthy banana plants in Zhanjiang, Guangdong province, were used as test materials. The taxonomic status was identified via morphological observation, and 16S rRNA gene sequencing. Furthermore, the biocontrol potential and environmental adaptability were systematically investigated through enzyme activity determination, nutrient utilization spectrum analysis, dual culture assay and pot experiments. Both strains were identified as Bacillus amyloliquefaciens, with in vitro inhibition rates of 35.3% and 38.3% against Foc4, respectively. Notably, the starch hydrolysis ability of 6ZJF-5 was significantly superior to that of 9ZJF-4 (P<0.05). Both strains displayed extremely strong environmental adaptability, tolerating a pH range of 4-10, a temperature range of 15-45 ℃, and 0%-11% NaCl. They could efficiently utilize 13 carbon sources and 9 nitrogen sources, with good stability in rhizosphere colonization. Under pot experiment conditions, the control efficacies against banana Fusarium wilt reached 52.2% and 58.1%, respectively, with 6ZJF-5 showing a better control effect. This study explored region-specific biocontrol microbial resources suitable for banana-growing areas along the South China coast, clarified the functional complementary characteristics of the two strains, and would provide new microbial materials and theoretical support for the green control of banana Fusarium wilt.

Pitaya (Hylocereus undatus) is a climbing succulent shrub of the Cactaceae family, with edible, medicinal and ornamental values, and has become an important economic crop in tropical and subtropical regions of China. As an emerging high-quality pitaya cultivation area in China, Yunnan province has not yet clarified the epidemic regularity and pathogen composition of pitaya fruit rot, which has become a key bottleneck restricting the sustainable development of the local industry. To identify the pathogenic species and infection characteristics of the disease, a systematic survey was conducted in multiple pitaya plantations across four major producing areas in Yunnan province, including Xishuangbanna Dai Autonomous Prefecture, Pu’er city, Yuanjiang county and Hekou county. The pathogen species were identified by combining morphological observation, multi-gene sequence analysis and verification of Koch’s postulates. Meanwhile, qRT-PCR assay was used to detect the biomass of pathogens in host tissues and clarify the infection dynamics. The results showed that pitaya fruit rot was prevalent in the surveyed areas, with an average incidence rate of 29.23%. Morphological characterization and molecular identification confirmed that Neoscytalidium dimidiatum and Fusarium incarnatum were the primary pathogens causing the disease. Both single and mixed inoculations induced typical rot symptoms; however, disease progression was significantly accelerated under mixed inoculation, with lesion expansion rates and rot severity markedly higher than those observed under single inoculation, and symptoms were highly consistent with natural field infections. qRT-PCR assays revealed significantly elevated relative abundance of F. incarnatum under mixed inoculation compared to single inoculation, suggesting a mixed infection interaction between these two pathogens that collectively promotes disease development. This study confirms that pitaya fruit rot in Yunnan province is caused by mixed infection of F. incarnatum and N. dimidiatum. The finding that mixed inoculation significantly aggravates disease symptoms indicates that mixed infection represents an important factor underlying severe field outbreaks, providing crucial theoretical support for early accurate diagnosis, epidemic warning, and the development of comprehensive control strategies.

Pestalotiopsis-like species are known as important plant pathogens that infect a variety of tropical and subtropical crops. Here, we report the identification of two isolates HPE1 and HPE2 obtained from pathogens on a suspected leaf spot disease sample in Yunnan Pu’er coffee base. The colony of the isolate on PDA was round in shape, the mycelium was white, the edge was neat, and the back was light yellow. Black conidia could be produced on the mycelium in the late stage of culture. Conidia were five-celled, straight or slightly curved in shape, with sharp ends. The size was (18.07-31.25)µm×(4.81-9.55)µm. There were four diaphragms, 3 olive brown cells of size ranged from 13.4 µm to 25.8 µm. The aspersorium was colorless and transparent, short cone-shaped, terminal or lateral with 1-3 appendages, mostly 2, and size was 6.13-26.93 µm, curved. The basal cell was conic in shape, with 1 root of accessory trichome and 3.51-11.85 µm in length. Coffea arabica exhibited symptoms after inoculated with the isolates, while the re-isolated conidia showed identical morphological characteristics. The ITS, β-tubulin, TEF single sequence tree and combined ITS-β-tubulin-TEF sequence tree analysis showed that the three gene trees could clearly cluster the isolates HPE1 and HPE2 with Pestalotiopsis trachicarpicola, the node self-bootstrapping rate was 99%. Therefore, the pathogen was confirmed as Pestalotiopsis trachicarpicola by morphological and molecular identification. The optimal temperature for mycelial growth was 25 ℃, the most optimal pH was 8, and full sunlight condition promoted mycelial growth. Prochloraz, tebuconazole and fluconazole displayed significant inhibitory effects on the mycelium growth of the pathogen with EC₅₀ values less than 1 μg/mL. This is the first report of Pestalotiopsis trachicarpicola infecting coffee, which is of great significance for the monitoring and early warning of coffee diseases, the study of pathogen diversity and the development of green prevention and control technologies in China.

This study investigated the mechanism and control efficacy of LvnongLin^® compound microbial fertilizer against citrus Huanglongbing (HLB) from the perspectives of soil nutrients and microbial community structure and diversity, aiming to provide technical support for sustainable HLB management. A field experiment was conducted in a plot with severe HLB incidence. Four treatments were established, control (CK), root application of LvnongLin^® compound microbial fertilizer (LNL) (T₁), foliar application (T₂), and combined root + foliar application (T₃). The Candidatus Liberibacter asiaticus (CLas) carrier rate, plant growth parameters and soil nutrients were determined; high-throughput sequencing was used to analyze the community structure and diversity of bacteria and fungi in leaf midribs. T₃ significantly increased the contents of soil organic matter, ammonium nitrogen, available phosphorus, available potassium and pH value in the rhizosphere, while effectively reducing soil salinity, showing better effects than root-only (T₁) or foliage-only (T₂) application. All treatments exhibited certain control effects compared with CK, with T₃ showing the best comprehensive efficacy. T₃ reduced the infection rate of CLas in leaf midribs of citrus at harvest stage to 11.67%, with an average control efficacy of 86.36%. Meanwhile, T₃ significantly decreased the starch content in leaf midribs, and significantly increased leaf chlorophyll content, yield per plant, juice yield and fruit soluble solids content. Among the endophytic microbial indices of leaf midribs, analysis of amplicon sequence variant (ASV) showed that the T₃ had the largest number of unique bacterial ASV, while the T₁ contained the highest count of unique fungal ASV. The bacterial Chao1 and Shannon indices followed the order T₃>T₂>T₁>CK, whereas the fungal indices followed T₁>CK>T₂>T₃. Principal coordinate analysis (PCoA) showed that the bacterial and fungal community structures were similar between T₂ and T₃, but the within-group individual differences of the communities were larger for CK and T₁. T₃ exhibited the lowest abundance of Candidatus Liberibacter, and significantly enriched the bacterial genera Burkholderia-Caballeronia-Paraburkholderia and Sphingomonas. Bacillus was enriched only in T₁ (4.32%) and T₃ (1.19%). T₃ also enriched the fungal genera Phoma and Fusarium. LEfSe analysis identified 6 bacterial and 3 fungal species as key differential taxa in T₃. Co-occurrence network analysis revealed that T₃ had the highest node number, edge number and modularity in the bacterial network, but the lowest in the fungal network. The combined root and foliar application of LNL can effectively improve rhizosphere soil nutrients, optimize the endophytic microbial community structure in leaf midribs, promote citrus growth, and thereby reduce the incidence and severity of HLB.

Rice orange leaf disease (ROLD), caused by phytoplasma, is an important disease affecting rice production. This study aimed to identify the pathogen causing suspected ROLD in certain rice fields in Lingshui county, Hainan province in 2025, and to evaluate its distribution and epidemic risks, thereby providing a scientific basis for developing effective prevention and control strategies. Total DNA was extracted from rice samples exhibiting typical orange leaf symptoms collected from Lingshui county. The 16S rRNA gene fragment of the phytoplasma was amplified using nested PCR with universal primers. Following cloning and sequencing, simulated restriction fragment length polymorphism (RFLP) analysis and phylogenetic tree construction were conducted using the iPhyClassifier online tool to determine the species and subgroup of the pathogen. Furthermore, PCR detection using ROLD phytoplasma-specific primers was performed on both symptomatic and asymptomatic samples collected from Lingshui, Changjiang, Lingao and other areas in Hainan to clarify the regional distribution of the disease. A 1246 bp 16S rRNA gene sequence was successfully amplified from the typical symptomatic samples. Sequence analysis and simulated RFLP identified the pathogen as the rice orange leaf phytoplasma, which belongs to the 16SrⅠ-B subgroup. Regional surveys indicated that suspected symptoms were exclusively observed in Lingshui, Changjiang, and Lingao, with Yingzhou town and Longguang town in Lingshui experiencing the most severe outbreaks. Specific detection results showed that among the 97 suspected samples collected from Tianzai and Eʼzai villages in Yingzhou town, and Danlu village in Longguang town, the phytoplasma detection rate was 87.5%, 90.0% and 80.0%, respectively. Out of 30 asymptomatic samples, only two from Tianzai village tested positive, yielding a detection rate of 6.7%. Additionally, single suspected symptomatic sample collected from Changjiang and Lingao respectively both tested positive for the phytoplasma. In conclusion, the pathogen responsible for ROLD in Lingshui, Hainan, is confirmed as a phytoplasma belonging to the 16SrⅠ-B subgroup. Currently, the disease exhibits a localized occurrence pattern in Hainan, with Lingshui county identified as the primary high-risk area. It is recommended to strengthen source management and monitoring in the rice-growing regions of Yingzhou and Longguang towns to strictly prevent the further spread of the disease.

Amino-functionalized metal-organic framework UiO-66-NH₂ was prepared by solvothermal method, and acetamiprid (Ace) was loaded via physical adsorption to construct a pH-responsive nano-delivery system Ace@UiO-66- NH₂ to improve the control efficacy of chemical pesticides against Cylas formicarius (Fabricius) and solve the problems of low utilization efficiency and poor safety to non-target organisms of conventional pesticides. Scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and N₂ adsorption-desorption confirmed that acetamiprid was efficiently loaded mainly through pore encapsulation and hydrogen bonding interaction with a drug loading content of 62.89%, while the framework structure of the carrier remained intact. In vitro release tests showed that the system exhibited obvious pH-responsive properties, with the fastest release rate and a cumulative release rate of 93.80% at 120 h in alkaline medium (pH 9.0), which matched the alkaline microenvironment in the midgut of Cylas formicarius to achieve targeted release. Bioactivity assays revealed that the LC₅₀ value of Ace@UiO-66- NH₂ against adult C. formicarius was 113.0382 mg/L and 21.2517 mg/L at 24 h and 48 h after treatment, respectively, showing significantly higher insecticidal toxicity than acetamiprid technical concentrate. Non-target safety evaluation indicated that the 48 h oral LD₅₀ of Ace@UiO-66-NH₂ to honeybees was 2.11 times that of acetamiprid, and the 48 h contact LC₅₀ to earthworms was 8.00 times that of acetamiprid, demonstrating remarkably improved safety to environmental non-target organisms. The as-constructed Ace@UiO-66-NH₂ nano-delivery system integrates the advantages of high drug loading, pH intelligent response, high insecticidal efficacy and environmental friendliness, and could provide a novel nanopesticide technology and theoretical support for the green and efficient control of Cylas formicarius.

To explore suitable preservation methods for long-term storage of coconut meat, fresh coconut meat was subjected to five treatments including liquid nitrogen quick-freezing followed by storage at -80 ℃, slow freezing at -18 ℃, room temperature storage at 25 ℃, and ⁶⁰Co γ-ray irradiation at 2.6 kGy and 8 kGy followed by storage at -18 ℃. The changes in sensory quality, juice loss rate, pH, acid value, and volatile components were measured during 0-16 d of storage. -80 ℃ quick-freezing effectively inhibited juice loss and lipid oxidation, with juice loss rate of 5.6% and acid value of 0.254 mg/g after 16 d, but the characteristic aroma components δ-octalactone and δ-decalactone were completely lost. 2.6 kGy irradiation combined with -18 ℃ freezing significantly improved the retention of δ-octalactone and δ-decalactone and slowed down the increase of acid value during the later storage period, with acid values lower than the non-irradiated -18 ℃ group after 16 d. Although 25 ℃ storage showed significant accumulation of characteristic lactones, the acid value reached 2.356 mg/g, indicating severe spoilage. Comprehensive analysis indicates that 2.6 kGy irradiation combined with -18 ℃ freezing can inhibit quality deterioration while preserving characteristic flavor, making it an effective method for long-term storage of coconut meat. -80 ℃ quick-freezing is suitable for processing scenarios focusing on physicochemical quality maintenance with low requirements for flavor retention.

To explore the effect of rice hydrolyzed protein (RHP) on the quality of freeze-dried pitaya powder, RHP with 0% to 25% soluble solids in juice was added during the preparation of pitaya powder, and the hygroscopicity, powder characteristics and sensory quality of the prepared powder were analyzed and determined. By comparing a series of key indicators such as equilibrium hygroscopic rate, angle of repose, particle density, Carr index (CI value), dissolution rate, color difference and sensory score, the quality changes of pitaya powder under different RHP additions were clarified. Under the condition of 25 ℃ and 75% RH, the change trend of moisture absorption rate of pitaya powder with different doses of RHP was similar. It increased rapidly in the early stage, and the growth rate gradually slowed down with time, and finally tended to be balanced. The equilibrium moisture absorption rate of the samples decreased from 17.71% to 14.49% with the increase of RHP addition. Comparing the fitting parameters of the five classical moisture absorption kinetic models, it was found that the logarithmic model had the best fitting performance for the six groups of samples, and the R² values were all greater than 0.97, and the RMSE values were all less than 0.54. Followed by the binomial, first-order kinetics, and Peleg models. In powder properties, the angle of repose, bulk density, tap density, CI value and dissolution rate of pitaya powder decreased with the increase of RHP addition. This indicates that RHP can effectively enhance the fluidity of fruit powder, but it will have an adverse effect on its solubility. In sensory quality, with the increase of RHP addition, the L^* value of the fruit powder increased significantly from 45.15 to 62.49, while the a^* and b^* values decreased from 37.18 and 13.19 to 27.85 and 2.84, respectively, respectively. When the addition amount was 5%, the ΔE value was the smallest, indicating that the natural color of pitaya could be well preserved under this condition. The sensory evaluation scores of pitaya powder with different RHP additions, from high to low, were as follows: 10% (43.91 points)>5% (42.88 points)>0% (42.14 points)>20% (39.11 points)>25% (37.72 points). When the RHP addition was 10%, the powder was bright red in color, evenly dispersed, rich in aroma, and pure in taste, and the sensory indexes reached the optimal balance.

It was aimed to investigate the effects of different intercropping patterns on the community composition of ammonia-oxidizing microorganisms in rubber plantation soils. Rubber monoculture was used as the control and three intercropping patterns, rubber (Hevea brasiliensis) with sharpleaf galangal (Alpinia oxyphylla Miq.), coffee (Coffea arabica L.), and kinggrass [Pennisetum purpureum Schumach. × Pennisetum glaucum (L.) R. Br.], were selected. Soil physicochemical properties were measured, and quantitative PCR (qPCR) combined with Illumina MiSeq high-throughput sequencing was employed to analyze the functional gene abundance, community structure, and key environmental drivers of ammonia-oxidizing bacteria (AOB), ammonia-oxidizing archaea (AOA), and complete ammonia oxidizers (Comammox) under different intercropping patterns. Compared with rubber monoculture, intercropping treatments significantly increased soil organic matter, total nitrogen, available phosphorus, available potassium contents and carbon-to-nitrogen ratio, while decreasing nitrate nitrogen content. In rubber plantation soils, the gene copy number of AOB was 1.7 times and 2.1 times higher than that of AOA and Comammox, respectively, indicating that AOB were the dominant group. There were significant differences in the effects of different intercropping treatments on the gene abundance of ammonia-oxidizing microorganisms. Kinggrass and coffee intercropping significantly increased the gene copy numbers of AOA and AOB but decreased that of Comammox, whereas sharpleaf galangal intercropping significantly reduced the gene copy numbers of AOA, AOB and Comammox. The number of operational taxonomic units (OTUs) of the three ammonia-oxidizing microorganisms followed the order, Comammox (428) > AOA (73) > AOB (34). At the phylum and genus level, the dominant group of AOA was unclassified__Archaea, whose relative abundance increased by 41.95%, 22.96% and 21.37% under coffee, kinggrass and sharpleaf galangal intercropping, respectively. The dominant phylum of AOB was Proteobacteria, and the dominant genus was norank__Nitrosomonadaceae, the relative abundance of which increased by 58.35% under sharpleaf galangal intercropping but decreased by 15.64% under coffee intercropping. The dominant group of Comammox was unclassified__Bacteria, with its relative abundance increasing by 18.29%, 9.65% and 38.91% under coffee, kinggrass and sharpleaf galangal intercropping, respectively. Furthermore, all intercropping treatments significantly affected the relative abundances of key functional genera involved in the ammonia oxidation process (Nitrososphaera, Nitrosospira and Nitrospira). Correlation analysis revealed that the dominant genera of AOA were significantly positively correlated with total nitrogen, ammonium nitrogen, and organic matter, but significantly negatively correlated with available phosphorus and available potassium; the dominant genera of AOB were significantly positively correlated with total nitrogen, ammonium nitrogen, and organic matter; and the dominant genera of Comammox were significantly positively correlated with total nitrogen, nitrate nitrogen, and organic matter. In conclusion, intercropping can effectively improve the physical and chemical properties of the soil in rubber plantations, regulate the quantity and community structure of ammonia-oxidizing microorganisms, and thereby control the efficiency of soil nitrogen transformation. Appropriate intercropping patterns are of great significance for improving the ecological functions and quality of the soil in rubber plantations.

Rubber plantations at five age stages (young: 5 a, middle-aged: 10 a, mature: 20 a, over-mature: 30 a, and regenerated plantations: 40 a) in Danzhou city, Hainan province were selected to reveal the water conservation function of the litter layer in rubber plantations of different age. The litter standing crop, water-holding rate, water absorption rate and effective interception capacity were measured, and the variations with stand ages were analyzed. The total litter standing stock increased first and then stabilized with increasing stand ages, ranging from 1153.9 to 3997.8 kg/hm², with leaf litter accounting for 62.4%-100.0%. The water-holding rate and water absorption rate of each component showed significant logarithmic and power function relationships with soaking time, respectively. Both the water-holding rate and the water absorption rate ranked as semi-decomposed leaf litter > undecomposed leaf litter > branches litter > pericarp litter > seeds litter. The modified interception amount of the young plantations was 3659.7 kg/hm², which was significantly lower than that of the middle-aged plantations (9371.1 kg/hm²), mature forest (9880.0 kg/hm²), over-mature plantations (9579.4 kg/hm²) and regenerated plantations (9061.0 kg/hm²). Leaf litter contributed 83.6%- 100.0% of the total modified interception amount. In summary, the hydrological function of rubber plantation litter changes dynamically with stand ages, being the weakest in the young stage and stabilizing after the middle-aged stage but with a shift in component composition. The results would provide a scientific basis for evaluating the water conservation function and managing rubber plantation stands.

The study was conducted from September 2024 to September 2025 in the macadamia demonstration garden of Guangxi Institute of South Asian Tropical Agricultural Sciences to provide scientific support for differentiated water management of macadamia orchards with different forest ages, and to clarify the dynamics of tree sap flow and the law of environmental response. Taking 5-, 7-, 22- and 31-year-old Macadamia trees as the research object, the sap flow rate was measured by thermal diffusion stem flow meter, and the related environmental factors were monitored by automatic weather station and soil moisture sensor to analyze the age difference, seasonal characteristics and driving mechanism of sap flow rate. The sap flow rates of different forest ages were significantly different, and the sap flow rate decreased with the increase of tree age. The sap flow rate of 7-year-old trees was the highest [0.1254 mL/(cm²·min)], and the sap flow rates of 5-, 22- and 31-year-old trees were 0.1077, 0.0830 and 0.0628 mL/(cm²∙min), respectively. The sap flow of each age group was characterized by high values in summer and autumn and low values in winter. The sap flow of young trees (5 and 7 years) increased significantly in May, and that of mature trees (22 and 31 years) increased significantly from June to July. Solar radiation was the key influencing factor, but the driving mechanism is different among forest ages. The sap flow rate of 5-year-old trees was dominated by meteorological factors. The sap flow rates of 7-, 22- and 31-year-old trees were driven by meteorological factors and soil moisture. The effect of soil moisture on the sap flow rate was regulated by weather conditions, which promoted sap flow on non-rainy days and inhibited sap flow on rainy days when the soil moisture was saturated. The sap flow dynamics and environmental response patterns of Macadamia trees with different forest ages revealed in this study could provide a scientific basis for precise water regulation, efficient utilization and planting management optimization of Macadamia orchards with different forest ages.

To elucidate the effects and driving mechanisms of intercropping the leguminous green manure Indigofera spicata on soil microbial communities in orchards, a field experiment was conducted in a subtropical orchard in southern Fujian, China, with five treatments, an unplanted control (CK) and plots planted for 3 (T₁), 4 (T₂), 5 (T₃) and 6 (T₄) years. Full-length 16S rRNA and ITS amplicon sequencing on the PacBio platform, combined with soil physicochemical analysis, redundancy analysis (RDA), and cross-kingdom co-occurrence network analysis, were employed to systematically investigate the effects of different planting durations on soil properties, microbial diversity, community composition, and bacteria-fungi interaction networks. I. spicata planting significantly increased soil pH (from 6.257 in CK to 7.010 in T₄) and organic matter content (T₂ and T₃ reached the highest values of 14.190 and 14.127 g/kg, respectively), whereas total nitrogen and alkali-hydrolyzable nitrogen declined overall with planting duration, presumably due to sustained mineral nitrogen uptake by plant growth. Phosphorus and potassium indices exhibited complex nonlinear responses. Shannon and Chao1 indices of both bacteria and fungi were significantly higher in all planted treatments than in CK. PCoA based on Bray-Curtis dissimilarity showed significant separation among treatments for both bacterial (R²=0.8189, P=0.001) and fungal (R²=0.8050, P=0.001) communities. Community composition underwent directional succession with planting duration. Acidobacteria continuously decreased in the bacterial community (from 29.84% in CK to 16.49% in T₃), while Firmicutes was periodically enriched. In the fungal community, Ascomycota increased significantly and Basidiomycota decreased sharply, with Neocosmospora consistently maintained above 13.00% in T₂-T₄ as a core dominant genus, and Mortierella specifically enriched in T₃. The successional patterns are consistent with the oligotrophic-copiotrophic ecological strategy theory. RDA revealed that the first two axes explained 79.05% and 58.48% of the variation in bacterial and fungal communities, respectively. Total nitrogen, alkali-hydrolyzable nitrogen, and organic matter were the shared core drivers of both communities, with pH exerting a stronger regulatory effect on fungi (R²=0.630) than on bacteria (R²=0.452). A cross-kingdom bacteria-fungi co-occurrence network comprising 181 nodes and 1204 edges was constructed, with positive correlations accounting for 57.1% and cross-kingdom links for 35.2%, exhibiting significant modular structure (Q=0.335). 21 hub species were identified whose abundances were significantly and positively correlated with organic matter, alkali-hydrolyzable nitrogen, and total potassium (R²>0.600, P<0.001), indicating that carbon and nitrogen accumulation is the key driving force sustaining cross-kingdom interaction patterns. Overall, the optimal soil microbial improvement was achieved at 4-5 years of planting, which could serve as a reference for adjusting green manure management strategies. This study would provide a scientific basis for the application of leguminous green manure in soil ecological restoration of subtropical orchards.