The inoculation of biocontrol fungi may affect the community structure of microorganisms in the soil, and changes in soil microbial community structure may in turn affect the control effectiveness. This study focused on the most harmful invasive pest, the red imported fire ant Solenopsis invicta Buren. The highly pathogenic Beauveria bassiana strain HHY-B was applied to its nest to reveal the impact of pathogen infection on the nest microbial community structure of the red imported fire ant. The microbiome analysis was conducted on soil samples of B. bassiana infected ant nests after 48 and 96 hours, as well as uninfected ant nests using high-throughput sequencing technology. A total of 648 708 valid bacterial sequences were obtained, belonging to 38 phylum, 127 classes, 274 orders, 451 families and 897 genus. 898 443 fungal sequences were also obtained, belonging to 12 phylum, 38 classes, 88 orders, 197 families, 377 genus. The Proteobacteria and Actinobacteria dominated the soil bacterial community in ant nests. Treatment with B. bassiana significantly increased the relative abundance of Proteobacteria in ant nests (P<0.05), but had no significant effect on the relative abundance of Actinobacteria. Ascomycota dominated the fungal community in the nest soil, and its relative abundance treated with B. bassiana was significantly increased in ant nests (P<0.05). In terms of relative abundance at the genus level, the genus of Beauveria showed an dominate fungi in the two treatment groups, which was not found in the control group. The KEGG pathway analysis showed that the differential bacteria were mainly focused on metabolic pathways, biosynthesis of secondary metabolites, microbial metabolism in various environments, biosynthesis of amino acids, carbon metabolism, two-component systems, ribosomes and other metabolic pathways. The enrichment level of the pathways in the control group was higher than that in the treatment group. This study revealed the changes in the microbial community structure of the red imported fire ant nests after treatment with B. bassiana, which helps to the further understanding of the mechanism of B. bassiana on the red imported fire ants and the living environment, and provides theoretical basis for the biological control for the red imported fire ants.

To address mango leaf disease recognition in complex in-field scenes, where background interference and simultaneous infections across multiple leaves lead to feature recognition difficulties and multi-task segmentation problems, this paper proposes G-Mask2Former, a structure-space-guided model that achieves collaborative segmentation of leaf instances and lesion semantics. The method jointly learns leaf and lesion segmentation within a shared feature space, and leverages a leaf-structure prior to impose spatial constraints on the lesion predictions. First, based on Mask2Former, we use multi-scale pixel representations and mask attention to extract effective features of mango leaf diseases in complex scenes; by constructing pseudo-instances of lesions, we achieve leaf instance segmentation and lesion semantic segmentation within a single model, thereby simplifying model deployment and inference. Second, through a leaf structure-space soft gating module, the model is guided to focus on leaf regions, reducing interference from complex environments. Finally, we conduct experiments on a mango leaf disease dataset collected in complex in-field scenes and perform comparative analyses against other models. The proposed method achieves superior overall performance over classical baselines for segmenting mango leaves and diseases in complex in-field scenes. On the test set, the average precision (AP) for leaf instance segmentation reaches 87.37%, while the mean Intersection-over-Union (mIoU) for lesion semantic segmentation reaches 82.83%. The proposed method would provide an effective solution for mango leaf disease segmentation in complex environments and facilitates quantitative disease assessment.

To investigate the differences in response and labeling efficiency of C₃ and C₄ crops to carbon isotope pulse labeling, this experiment selected C₃ crops (rice and peanut) and C₄ crops (maize and sugarcane) as research subjects. A total of five rounds of ¹³C pulse labeling were conducted in pot experiments to analyze the ¹³C enrichment abundance, fixation amount, and labeling efficiency of the crops, aiming to reveal the differences in carbon fixation and pulse labeling efficiency between C₃ and C₄ crops. The results showed that under labeling treatment, the δ¹³C values and isotope abundance F values of C₃ and C₄ crops showed significant differences, following a consistent pattern: C₃ crops>C₄ crops. The δ¹³C values of the four crop types were as follows: rice (396.90‰-410.05‰)>peanut (269.51‰-364.66‰)>maize (148.15‰-182.47‰)>sugarcane (152.50‰-153.91‰). Under non-labeled treatment, δ¹³C values were as follows: sugarcane (-15.63‰ to -15.16‰)>maize (-18.25‰ to -16.52‰)>rice (-34.53‰ to -33.82‰)=peanut (-35.41‰ to-33.37‰). The ¹³C fixation amount and labeling efficiency showed consistent trends, with no significant differences between C₃ and C₄ crops. Among the four crops, peanut and sugarcane treatments were significantly higher than rice and maize, and peanut was significantly higher than rice. Peanut had the highest labeling efficiency at 46.02%, followed by sugarcane at 33.27%, and rice had the lowest at 24.55%. This study reveals the response differences of C₃ and C₄ crops to ¹³C pulse labeling and provides important data support for the application of stable isotope techniques in crop carbon labeling.

Rubber tree anthracnose is one of the two major foliar diseases of rubber trees, ranking second in severity only to powdery mildew. It has caused significant economic losses to rubber latex production during rubber tree cultivation in China. Against this backdrop, this study focuses on the pathogen of rubber tree anthracnose, investigating its fundamental biological characteristics, molecular identification, antifungal spectrum determination of biocontrol agents, and green prevention strategies. The research begins with a survey of anthracnose incidence in major rubber tree cultivation areas of Hainan province, collecting diseased leaves from rubber forests in Qionghai, Baoting and Chengmai. Pathogenic fungi were isolated and purified, followed by molecular identification and antifungal spectrum analysis by biocontrol agents. Finally, a strain (HZS-BT) isolated from Baoting was subjected to fundamental biological characteristic studies. The findings reveal that, through field surveys of rubber tree anthracnose in various regions of Hainan, it was observed that currently predominant rubber tree varieties in Hainan, such as RY73397, PR107 and RRIM600, exhibit poor resistance to anthracnose under current climatic and ecological conditions. By amplifying core genes, multiplex gene sequencing, and specific primer detection, followed by BLAST comparison with genome sequences of standard strains in the NCBI database, the anthracnose pathogen strain HZS-BT isolated from Baoting was identified as Colletotrichum siamense. The optimal growth temperature for the tested anthracnose strain is 28 ℃, with a preferred pH of 8.0, though the strain demonstrates a broad pH adaptability range. The most suitable carbon and nitrogen sources for its growth are sorbitol and beef extract, respectively. Antifungal spectrum analysis indicates that all 11 biocontrol strains possess potential for biological control applications against anthracnose. This study provides a theoretical foundation for the green prevention of rubber tree anthracnose.

This study investigated the quality variation and climatic adaptation mechanisms of Hainan large-leaf and Yunnan large-leaf black tea through multi-component analysis and aroma characterization of tea samples from Wuzhishan, Wanning, and Baisha. The results demonstrated that Hainan large-leaf tea exhibited superior photosynthetic performance in Wanning and Wuzhishan, with maximum net photosynthetic rate reaching 7.28 μmol/(m²·s), accompanied by high amino acid content (up to 93.50 μmol/g) and moderate caffeine levels (3.93%-4.31%), forming a distinctive "high amino acid-moderate astringency" flavor profile. Aroma component analysis revealed significant regional differences in Hainan large-leaf tea, with Wanning characterized by benzaldehyde (14.51%)-dominant fruity notes and Baisha featuring linalool (31.18%)-rich floral aroma. Climatic adaptability analysis indicated that higher temperatures in Wanning (annual average 24.40 ℃) promoted the synthesis of tea polyphenols and catechins, while the cooler climate of Baisha (annual average 22.30 ℃) was more conducive to theaflavins formation and aroma compound accumulation. Compared with Yunnan large-leaf tea, Hainan large-leaf tea showed significant advantages in photosynthetic efficiency, amino acid accumulation, and aroma composition. The findings would provide theoretical support for optimizing production regions and developing characteristic products of Hainan black tea, with important implications for enhancing its market competitiveness.

The study was aimed to screen actinomycetes with good control effects on sugarcane red rot and enrich the resources of biocontrol bacteria for sugarcane red rot. JY53, WK29 and JR28 were screened from sugarcane rhizosphere soil, which showed superior antifungal effects against sugarcane red rot pathogen. They were identified as Streptomyces virginiae, S. iranensis and S. lavendulae, respectively. The antifungal rate of WK29 against six plant pathogens ranged from 68.41% to 78.22%. The antifungal rate of JY53 against five pathogens ranged from 58.66% to 72.85%. The inhibition rates of four plant pathogens by JR28 ranged from 27.69% to 60.15%. All the strains exhibited a certain broad-spectrum activity. Further exploration of the antifungal mechanism revealed that JY53 inhibited pathogen growth by producing β-glucanase, siderophore and volatile substances, while WK29 and JR28 inhibited pathogen growth by producing protease, β-glucanase, cellulase, siderophore and volatile substances. Pot experiment showed that after treatment with the bacterial solution of JY53, WK29 and JR28, the incidence indice of sugarcane red rot was 28.00, 25.33 and 22.67, respectively, significantly lower than 64.00 of the CK, and had a good growth promoting effect. This study indicates that actinomycetes JY53, WK29 and JR28, have certain effects on the prevention and control of sugarcane red rot disease, further enriching the resources of biocontrol bacteria for sugarcane red rot disease.

To establish a regeneration system for somatic embryo-derived plants from the anthers of the triploid rubber tree clone Yunyan 73-46, this study utilized anthers as explants and employed an orthogonal experimental design to examine the effects of various hormone combinations on callus and somatic embryo induction efficiency. Furthermore, the morphological characteristics and differentiation capacity of callus under different culture duration were analyzed. Hormones were crucial for callus induction. In the absence of hormones, anthers failed to dedifferentiate and underwent browning and necrosis after 10d. In media containing 2,4-D, NAA, KT and TDZ, anther dedifferentiation to produce callus occurred with induction rates ranging from 15% to 91.56%, with a mean of (69.41±30.37)%. The impact of 2,4-D, NAA, KT and TDZ on callus induction rate and subsequent somatic embryogenesis rate were all highly significant (P<0.01), with the order of influence being 2,4-D>TDZ>NAA>KT. The optimal combination identified through comprehensive screening was 2,4-D 1.0 mg/L+NAA 0.8 mg/L+TDZ 0.02 mg/L. Upon verification, the callus induction rate and subsequent somatic embryogenesis rate was (86.15±1.53)% and (14.46±0.89)%, respectively, marking significant improvements of 2.31% and 5.40% over the best experimental combination (G7). The somatic embryogenesis capacity of this clone was generally low, with somatic embryo formation rates ranging from 6.91% to 19.31%, with a mean of (10.58±3.95)%. The effects of 6-BA, ABA, NAA and KT on somatic embryogenesis rate were highly significant (P<0.01), with the order of influence being ABA>6-BA>NAA>KT. The optimal combination was 6-BA 0.4 mg/L+ABA 0.2 mg/L+NAA 0.2 mg/L+KT 0.2 mg/L (M9), achieving a somatic embryogenesis rate of (19.31±0.60)%, which was significantly higher than other treatments. The optimal culture duration for callus was determined to be 55 d, which exhibited superior growth status without browning and the strongest somatic embryo differentiation capacity. The somatic embryogenesis rate was (30.83±1.67)%, the cotyledonary embryo formation rate was (18.33±0.83)%, and the average number of somatic embryos was (0.63±0.03), all of which were extremely significantly higher than those at other culture durations. By optimizing the hormone ratios during callus induction and somatic embryogenesis stages of Yunyan 73-46 anthers, coupled with adjusting the duration of callus induction culture, the production efficiency of anther-derived somatic embryo plantlets can be significantly enhanced. This approach would provide technical support for establishing a large-scale propagation system of somatic embryo plantlets for triploid rubber tree clones.

Natural rubber is an important industrial raw material and strategic resource. It has excellent properties such as comparable elasticity, flexibility and resistance to high temperature, which cannot be replaced by synthetic rubber. The rubber tree (Hevea brasiliensis) is still the only commercial source of natural rubber. Previous studies have reported the key genes involved in rubber biosynthesis including HbSRPP, HbHRT and HbFDP play crucial roles in increasing rubber yield, while MYB, as a transcription factor, may participate in the synthesis of natural rubber. In the study, a MYB transcription factor HblMYB16 gene was cloned from rubber tree, and bioinformatics and expression analysis were carried out successfully. The results showed that the open reading frame (ORF) of HblMYB16 was 1116 bp, encoding 371 amino acids, and the total average hydrophilicity was -0.498, which was a hydrophilic protein containing the R2R3-MYB domain and belonging to the MYB transcription factor family. HblMYB16 was highest expressed in latex and localized in the nucleus. It was found that jasmonic acid had a promoting effect on the expression of HblMYB16, HbSRPP, HbHRT and HbFDP, while ethylene only had an impact on the expression of HblMYB16 and HbFDP. At the same time, the interactions between HblMYB16 and the rubber biosynthesis key genes HbSRPP, HbHRT and HbFDP were verified by yeast one hybrid. The studies would lay a foundation for further revealing the molecular mechanism of HblMYB16 participating in natural rubber biosynthesis.

Rubber is a globally significant strategic raw material, playing an irreplaceable role in national defense, transportation, aerospace and medical equipment industries. However, pests such as the rubber tree leaf mite frequently occur in tropical rubber plantations, especially under conditions of high temperature and drought, where they are prone to large-scale outbreaks. Infestations result in symptoms such as leaf chlorosis, yellowing and premature defoliation, which severely compromise tree vitality and substantially reduce latex yield. Traditional pest and disease monitoring relies primarily on manual field surveys, which are time-consuming, labor-intensive, and limited in spatial scope. The constraints make it increasingly difficult to meet the needs of modern rubber plantations for rapid early warning and precise pest management. Remote sensing technology has demonstrated significant advantages in the monitoring of agricultural pests and diseases. It enables large-scale, rapid, non-contact and dynamic monitoring across multiple temporal scales. To address the limitations of conventional monitoring methods, such as low efficiency and inadequate accuracy, this study proposes a multi-source remote sensing approach that integrates ground-based ASD (Analytical Spectral Devices) hyperspectral data, proximal multispectral imagery, and field survey data to achieve rapid and accurate detection of rubber tree mite infestations. The study was conducted based on spectral reflectance data of rubber leaves collected in 2024 from the experimental station of Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences in Danzhou, Hainan province, along with UAV-based multispectral imagery. The raw spectral data were preprocessed using Multiplicative Scatter Correction (MSC), Savitzky-Golay (SG) smoothing and first-order derivative transformation. Four types of spectral feature variables were derived, including vegetation indices (VIs), hyperspectral features, continuum removal (CR) parameters and wavelet coefficients. Sensitive features were selected through a combination of the Least Absolute Shrinkage and Selection Operator (LASSO) and Pearson correlation coefficient analysis. Based on the selected features, three regression models, Multiple Linear Regression (MLR), Random Forest (RF) and Back Propagation Neural Network (BPNN), were developed to model rubber tree mite infestations levels. Results indicated that the ASD hyperspectral data yielded the best performance across all models, with the RF and BPNN models performing particularly well. Among them, the RF model achieved the highest coefficient of determination (R²) of 0.8361 and the lowest root mean square error (RMSE) of 0.6353 on the validation dataset, demonstrating a strong capacity for accurate infestation severity prediction. In conclusion, the integration of ASD hyperspectral data with the RF model enables the construction of a high-accuracy, strongly interpretable monitoring model for rubber tree mite infestations. This approach effectively supports early detection and quantitative classification of infestation levels in rubber tree mite infestations, and would provide essential technical guidance and theoretical support for precision plantation management and integrated pest control.

The study conducted a two-year field experiment to explore the effects of pesticide application via under-mulch drip irrigation on the control efficacy of major pests and comprehensive benefits in the field propagation of disease-free sugarcane original seedlings. With no pesticide application as the control (CK), four treatments were simultaneously set up, two drip irrigation pesticide application treatments (T₁ and T₂: applying 40% chlorantraniliprole·thiamethoxam WG via drip irrigation 3 times and 2 times, respectively), one unmanned aerial vehicle (UAV) spraying treatment (T₃: spraying 40% chlorantraniliprole·thiamethoxam WG 2 times), and one conventional root application treatment (T₄: applying 4% imidacloprid·bisultap GR 2 times). A comprehensive comparative analysis was performed on indicators such as the control efficacy against sugarcane borers, thrips, and aphids, as well as the propagation efficiency and economic benefits of disease-free sugarcane original seedlings, aiming to provide a theoretical basis for scientifically guiding sugarcane elite seed propagation bases to utilize existing under-mulch drip irrigation systems for efficient and economical control of major pests. In the early stage of seedling propagation, the two drip irrigation treatments (T₁ and T₂) exhibited the best control efficacy against the rate of borer-induced dead heart seedlings, reaching over 76.00%, with the dead heart seedling rate controlled below 1.20%, which was significantly lower than that of other pesticide treatments. In the middle and late stages of propagation, UAV spraying T₃ showed the highest control efficacy against the rate of borer-damaged plants, reaching 72.00%, followed by the two drip irrigation treatments T₁ and T₂ with control efficacy ranging from 61.00% to 66.00%. Specifically, except that the rate of borer-damaged plants of T₃ was significantly lower than that of T₂ in the 2023 experiment, there was no significant difference in the rate of borer-damaged plants between T₃ and T₁, T₂. Conventional root application T₄ had the lowest control efficacy, and the rate of borer-damaged plants was significantly lower than that of other pesticide treatments. In terms of the rates of borer-damaged internodes and borer-damaged buds, drip irrigation treatment T₁ (applied 3 times) showed the highest control efficacy, both reaching over 82.00%, with the rates of borer-damaged internodes and buds controlled below 0.73% and 0.28%, respectively, which were significantly lower than those of other pesticide treatments. For the two foliar pests (thrips and aphids), UAV spraying T₃ showed better control efficacy than other treatments, reaching over 70.00%, but there was no significant difference compared with the two drip irrigation treatments. In terms of seedling propagation efficiency, drip irrigation treatments T₁ and T₂ had the highest number of effective buds, reaching 138.71×10⁴, 136.53×10⁴ buds per hectare, respectively, which was more than 6.12% higher than that of conventional root application T₄, but there was no significant difference compared with UAV spraying T₃. In terms of comprehensive propagation benefits, compared with CK, drip irrigation treatments T₁ and T₂ had the highest increase in net income, reaching 31 300, 30 400 yuan/hm², respectively, with an input-output ratio of above 1∶30, which was much higher than the input-output ratio of approximately 1∶21 for UAV spraying T₃ and conventional root application T₄. Comprehensively, applying 40% chlorantraniliprole·thiamethoxam WG via drip irrigation 3 times can sustainably and efficiently control borers, thrips and aphids, balances propagation efficiency and benefits, and has the lowest rate of borer-damaged internodes in seed canes. Thus, it can be used as the optimal scheme for controlling above-ground pests in the field propagation of disease-free sugarcane original seedlings.