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.

To address the limitation of conventional rubber plantation suitability assessments that overlook geographical environmental heterogeneity, this study proposes a suitability evaluation approach based on geographical zoning modeling. Eight key indicators were selected from three dimensions, topographic conditions, hydrothermal conditions, and cold damage risk, to construct the evaluation index system. The weight of these indicators was determined by integrating the Analytic Hierarchy Process (AHP) with the GeoDetector method. Using the Ailao Mountains ridge as a geographical demarcation, the rubber plantation area in Yunnan province was divided into western and eastern zones, for which region-specific factor suitability grading standards were established and applied for factor reclassification. Subsequently, the reclassified factors were integrated through linear weighting to produce a comprehensive suitability evaluation, classifying the results into four categories, unsuitable, marginally suitable, moderately suitable, and highly suitable. Among the six prefecture-level regions engaged in rubber cultivation, highly suitable areas accounted for approximately 4.29% of the total land area, moderately suitable areas for 2.79%, and marginally suitable areas for 5.06%, totaling about 12.14%. These areas are mainly concentrated in Xishuangbanna, Pu'er and Honghe. Overlay analysis with 2024 rubber plantation distribution data revealed that about 47.80% of existing plantations in highly suitable zones, 22.09% in moderately suitable zones, and 19.29% in marginally suitable zones, accounting for a combined 89.18%. This distribution shows a high degree of spatial consistency with the actual planting patterns. The evaluation results, with a spatial resolution of 10 m, are capable of reflecting fine-scale variations in Yunnan's mountainous environments, and can thus provide valuable references for rubber plantation planning and adjustment in Yunnan province.

Mango is one of the most widely cultivated and economically significant fruit trees in tropical regions of China, playing a vital role in optimizing agricultural structure and promoting rural revitalization. Scientifically delineating suitable planting zones for mango is essential for precise resource allocation and the high-quality development of the industry. However, most existing studies focus on climatic and topographic factors, with insufficient systematic consideration of soil physicochemical properties. In addition, current suitability evaluations often suffer from strong subjectivity in indicator selection and low integration of evaluation methods. To address these gaps, this study took Sanya city as the research area and developed a comprehensive evaluation model for mango planting suitability. First, the MaxEnt model was employed to identify key environmental factors and extract response curves for constructing membership functions. Second, an improved three-scale Analytic Hierarchy Process (3-scale AHP) and the entropy weight method were applied to determine subjective and objective weights, respectively, which were then integrated using a game theory-based weighting approach. Finally, the study area was classified into three planting suitability zones based on a comprehensive suitability index, and field surveys were conducted for validation. Bulk density, pH, cation exchange capacity (CEC), silt content, total potassium, soil type, slope, elevation, sunshine hours during the fruit maturity and harvest period, and annual maximum temperature were the ten dominant factors, with soil-related variables playing a critical role in the model. The suitable area covered 117 939 hm², accounting for 61% of Sanya's total area, with the most advantageous zones concentrated in southern Yazhou and southern Tianya. Advantageous zones were characterized by "low elevation–slightly acidic–potassium-rich–high permeability–high sunshine" conditions, which are conducive to high and stable mango yields with premium quality. The "factor selection–membership function construction–game theory-based weighting–suitability zoning" evaluation framework proposed in this study would provide both theoretical and methodological support for precision planting of tropical fruit trees and the optimization of regional agricultural spatial layouts.

Flower bud differentiation marks a critical transition period in plants from vegetative to reproductive growth. During this process, flavonoids, a key class of secondary metabolites in plants, do not directly influence flower bud differentiation. Instead, they play a vital role in the morphogenesis and developmental regulation of flower buds, serving as an indispensable material foundation for the normal formation and development of floral organs. They regulate the internal environmental homeostasis required for mango axillary bud differentiation, creating suitable conditions for the transformation of axillary buds into flower buds. Through pathways such as adjusting hormone balance, mediating signal transduction, and maintaining stable cellular metabolism, they indirectly promote the transformation of mango axillary buds into flower buds with corresponding morphological and physiological characteristics. Building upon the research group’s prior findings, this study demonstrated that removing terminal flowers during mango axillary bud conversion could delay flowering. Flower bud differentiation marks a critical transition period in plants from vegetative to reproductive growth. During this process, flavonoid, a key class of secondary metabolites in plants, do not directly influence flower bud differentiation. Instead, they play a vital role in the morphogenesis and developmental regulation of flower buds, serving as an indispensable material foundation for the normal formation and development of floral organs. They regulate the internal environmental homeostasis required for mango axillary bud differentiation, creating suitable conditions for the transformation of axillary buds into flower buds. Through pathways such as adjusting hormone balance, mediating signal transduction, and maintaining stable cellular metabolism, they indirectly promote the transformation of mango axillary buds into flower buds with corresponding morphological and physiological characteristics. Building upon the research group’s prior findings, this study demonstrated that removing terminal flowers during mango axillary bud conversion could delay flowering. This technique effectively mitigates damage from late spring frosts and other cold weather events, offering a crucial technical approach for securing mango yields. To delve into the underlying regulatory mechanisms, axillary buds from the “Guifei” mango cultivar at the Gan Zhuang Town mango base in Yuanjiang county, Yuxi city, Yunnan province (23.4210°N, 102.57189°E) were used as the research material. Axillary buds were collected after apical inflorescence removal and subjected to integrated transcriptomic and metabolomic analysis. This study examined gene expression and metabolic changes related to flavonoid biosynthesis following terminal inflorescence removal, revealing the association between flavonoid biosynthetic pathways and floral bud differentiation to effectively mitigate spring frost damage in mangoes. Results indicated that post-removal, gene expression changes in flavonoid biosynthesis pathways, including CHS1, CHI, F3'H, F3'5'H1, and F3H, affected the production of naringenin chalcone, naringenin, dihydroquercetin, cyanidin, pelargonidin,(+)-gallocatechin,2ʹ,3,4,4ʹ,6ʹ-pentahydroxychalcone, and pinobanksin. This indicates that the CHS1, CHI, F3H, F3'H, and F3'5'H1 genes accelerate the conversion of mango axillary buds into floral buds by regulating flavonoid biosynthesis, thereby promoting the formation of mango floral organs and providing new insights into the association between flavonoid biosynthesis and floral bud differentiation.

Cassava (Manihot esculenta Crantz), a vital tropical food crop, exhibits significant sensitivity to low temperature, which severely restricts its cultivation range. Lignin is a key stress-resistant component in cell walls, playing a crucial role in plant adaptation to low temperature stress. However, the function of cinnamyl alcohol dehydrogenase (CAD), a pivotal enzyme in lignin biosynthesis, during low-temperature stress responses remains unclear. This study analyzed physiological phenotypes, CAD enzyme activity and lignin accumulation in cassava under low temperature stress. CAD enzyme activity was significantly increased by 66.7% and lignin content was also increased by 14.8% at the low temperature of 10 ℃. Transcriptome profiling identified MeCAD2 as the key gene responsive to low temperature stress. Heterologous expression of MeCAD2 confirmed that its encoded MeCAD2 protein possessed CAD enzymatic activity. Virus-induced gene silencing (VIGS) of MeCAD2 in cassava resulted in a 18.9% reduction in CAD enzyme activity and a 12.3%–22.4% decrease in lignin content. Furthermore, under low temperature stress, MeCAD2-silenced plants exhibited exacerbated leaf damage, a 172.5% increase in malondialdehyde (MDA) accumulation, and intensified reactive oxygen species (ROS) staining. The results indicate that MeCAD2 enhances cassava low-temperature tolerance by regulating lignin deposition. This study elucidated the critical role of MeCAD2 in cassava’s response to low-temperature stress, providing a novel candidate gene for molecular breeding.

Coffee, one of the most important economic crops worldwide, is widely cultivated in tropical and subtropical regions and serves as a major source of income for many countries and regions. Caffeine (1,3,7-trimethylxanthine) is the main metabolite in coffee beans and related products, which not only imparts the characteristic bitter taste and stimulates effect of coffee but also exerts multiple biological functions. The N-methyltransferase (NMT) gene family plays a key role in the caffeine biosynthetic pathway. Therefore, systematic identification of coffee NMT family members and analysis of the expression patterns at different developmental stages are of great importance for investigating caffeine metabolism, improving coffee quality, and breeding stress-resistant varieties. In this study, a total of 27 NMT genes were identified in allotetraploid Coffea arabica, including 14 genes from the C subgenome and 13 from the E subgenome, distributed across 10 chromosomes. Gene structure analysis revealed that family members shared similar motif compositions but differed in intron arrangement and number. Cis-acting element analysis showed that the promoters of C. arabica NMT genes were enriched with various regulatory elements related to light response, stress response and hormone signaling, and contained transcription factor binding sites such as MYB, MYC and W-box. Transcriptome analysis further demonstrated that NMT genes exhibited dynamic expression during fruit development, with the ripening stage showing the highest number of differentially expressed genes (14 703), while the expansion stage showed the lowest (4419). Moreover, C. arabica NMT genes displayed clear temporal and tissue-specific expression patterns. Weighted gene co-expression network analysis (WGCNA) identified 12 co-expression modules, among which the ivory, coral1 and darkolivegreen modules were enriched in pathways related to environmental stress and protein folding, energy metabolism and nucleic acid metabolism, respectively. Core gene network analysis revealed the critical roles of NMT genes in caffeine metabolism, stress response, and developmental regulation. Taken together, this study systematically identified the NMT gene family in allotetraploid C. arabica, characterized the expression patterns during different stages of fruit development, and elucidated the potential functional differentiation, thereby providing a theoretical basis for coffee breeding.

As an important ornamental flower, Cymbidium sinense needs to undergo a long period of low temperature dormancy during its flower development to achieve flowering. SHORT VEGETATIVE PHASE (SVP) is a key regulator in plant flowering pathway and plays an important role in plant dormancy and flowering. In this study, three SVP homologous genes, named CsSVP1, CsSVP2 and CsSVP3, were cloned from Xiaoxiang. The results of bioinformatics analysis showed that the full-length of the three CsSVPs genes were 651 bp, 687 bp and 714 bp, encoding 216, 228 and 237 amino acids, respectively, and all of them contained conserved MADS-box and K-box domains. Amino acid sequence alignment and phylogenetic analysis showed that CsSVP1 had the highest similarity with CgSVP, CsSVP2 and CsSVP3 had the highest similarity with EpMADS18 and DhcSVP, respectively. CsSVP1 was closely related to CgSVP of C. goeringii. CsSVP2 was closely related to EpMADS18, while CsSVP3 was closely related to DhcSVP. Promoter cis-element analysis showed that the CsSVPs gene contained many light response, hormone response and other elements. The results of qRT-PCR showed that the three CsSVPs genes were expressed in roots, stems, leaves, flowers and fruits of C. sinense. The expression patterns of CsSVP1 and CsSVP3 genes were similar, which were accumulated in leaves and stems, and the expression levels in flowers and fruits were significantly decreased. The expression of CsSVP2 was the highest in fruit, followed by leaves, stems and flowers, suggesting that their biological functions may be quite different. At the same time, the expression in different floral organs was detected, and it was found that the three CsSVPs had the highest expression in sepals. Furthermore, the expression of CsSVP2 gene in different flower development stages was also detected. It was found that the expression level of CsSVP2 gene was the highest in the S₁ stage of early development, and decreased with the development of flower organs, and the expression level was the lowest in the S₅ stage of mature flowers. The overall expression levels of CsSVP1 and CsSVP3 in floral organs were not high. The expression level of CsSVP1 was the highest in S₂ period and the lowest in S₅ period. The expression level of CsSVP3 was the lowest in S₂ period, and the expression level continued to increase in the late stage of flower development. In addition, low temperature treatment found that the expression of CsSVP1 and CsSVP2 increased slightly after low temperature treatment, while CsSVP3 decreased significantly. In ABA treatment, only the expression of CsSVP1 was significantly inhibited, while CsSVP2 and CsSVP3 did not respond. The results suggest that different CsSVPs genes have different functions and may play different roles in the process of low temperature dormancy promoting flowering of orchids, which would provide an experimental basis for further analysis of the specific functions of SVP genes in the process of flower development.

Aquilaria sinensis, a plant belonging to the genus Aquilaria of the Thymelaeaceae family, can produce agarwood when exposed to natural factors (such as lightning strikes, fire, and insect bite) or artificial factors (such as cuts, holes, and inoculation of fungi). MADS is a transcription factor that plays a significant role in plant growth and development and stress response. However, its function in A. sinensis remains unclear. To elucidate the stress response of MADS-box genes in A. sinensis after injury, this study utilized transcriptomic data derived from A. sinensis to expression heatmaps and screen for differentially expressed genes, leading to the identification and cloning of a MADS-box encoding gene, designated AsMADS12, which exhibited significant differential expression. Comprehensive analyses were subsequently conducted on the domain architecture, physicochemical properties, phylogenetic relationships, and predicted secondary and tertiary structures of AsMADS12. The expression dynamics of the AsMADS12 at various time points after methyl jasmonate (MeJA) treatment were assessed via real-time quantitative PCR (RT-qPCR). Furthermore, subcellular localization of the AsMADS12 was determined by transiently expressing in onion epidermal cells (Agrobacterium-mediated infiltration) and observing fluorescence under a confocal laser scanning microscope. Sequence and evolutionary analyses revealed that AsMADS12 possessed a complete open reading frame (ORF) of 678 bp, encoding a protein of 255 amino acids. The predicted molecular weight of the encoded protein was 25.28 kDa. AsMADS12 contained a typical MEF2-like MADS domain and was classified as a MIKC-type transcription factor. The secondary structure of the protein was mainly composed of 52.00% α-helix, 11.56% extended chain, and 36.44% random coil. Phylogenetic cluster analysis revealed that AsMADS12 was clustered in the same branch as the MADS of Citrus sinensis and Citrus trifoliata. The subcellular localization experiment showed that the AsMADS12 protein was located in the nucleus. The real-time fluorescence quantitative results indicated that methyl jasmonate treatment could induce the expression of AsMADS12, and the expression level was the highest at 24 hours after treatment. It was speculated that AsMADS12 might play a potential role in the formation of agarwood in A. sinensis. This study completed the cloning of the gene for the first time and conducted preliminary exploration, laying the foundation for further research on whether it participates in the formation of agarwood and its role in biotic or abiotic stress responses, thereby providing a theoretical basis for understanding the molecular regulatory mechanism of agarwood formation in A sinensis.

Rubber tree (Hevea brasiliensis), an economically significant species, produces natural rubber, a strategic resource for China. Since rubber tree introduced from South America to Southeast Asia in the 19th century, rubber tree productivity has been substantially improved through sustained genetic improvement. This article comprehensively reviewed the botanical characteristics of the rubber tree, traced its history of introduction and domestication, and analyzed the current applications, achievements, challenges, and future research directions of both conventional breeding techniques (including hybrid breeding, polyploid breeding, mutagenesis breeding, etc.) and modern biotechnological breeding techniques (including molecular marker-assisted selection, genomic selection, genetic modification, gene editing, etc.) in rubber tree improvement. The review aims to provide a reference for researchers in rubber tree genetics and breeding, facilitate progress in this field, and promote the sustainable development of the natural rubber industry.

Hainan oil-tea Camellia (locally termed Shanyou in Hainan) is a regionally endemic decaploid species thriving under monsoonal tropical climatic conditions, which confers its distinctive flavor profile and quality attributes. This paper summarized recent research on Shanyou, examining its evolutionary distribution, growth traits, the exceptional quality characteristics of the oil, and methodologies for germplasm identification. Furthermore, strategic recommendations were proposed to advance the development of the Hainan Shanyou industry, in order to provide a critical foundation for subsequent research, product development, and the establishment of a premium Shanyou oil brand, thereby facilitating the distinctive development of the regional industry.