The three-year-old Phyllostachys prominens in the coastal sandy land of Dongshan was used to determine the contents of chlorophyll (Chl), soluble protein (SP), soluble sugar (SS), proline (Pro), and malondialdehyde (MDA) in the leaves in different seasons, and to explore the difference of physiological indexes of bamboo leaves under different seasonal environmental conditions, and analyze its adaptation in different seasonal environments in coastal sandy land, provide theoretical basis for constructing a more complete, abundant and economically valuable coastal shelter forest ecosystem. The chlorophyll a (Chla) and chlorophyll b (Chlb) had the same seasonal variation trend, and reached the highest content in summer. The total chlorophyll content in summer was 24.54%, 11.39% and 21.2% higher than that in autumn, winter and spring, respectively. The content of SP was the highest in winter and the lowest in summer. The content of SP in winter was 50.65%, 131.42% and 18.52% higher than that in spring, summer and autumn, respectively. The content of SS in summer was significantly higher than that in other seasons, which was 269.83%, 112.65% and 99.93% higher than that in spring, autumn and winter, respectively. The content of MDA decreased gradually from autumn to summer, and the difference between seasons was significant. The content of Pro was the highest in summer, which was 18.37%, 44.06% and 23.13% higher than that in spring, autumn and winter, respectively. Temperature and precipitation had significant effects on soluble sugar, soluble protein and malondialdehyde content. In the coastal area of Dongshan, during the same period of temperature and precipitation, compared with the highest and lowest periods of temperature (precipitation), the content of soluble sugar increased by 99.93%, the content of soluble protein decreased by 56.79%, and the content of malondialdehyde decreased by 52.72%. In summary, P. prominens ensures the smooth progress of photosynthesis by regulating chlorophyll content, and adapts to seasonal changes by regulating the content of osmotic substances. Photosynthesis and osmotic adjustment system are the key mechanisms for P. prominens to adapt to adversity environment.

Rubber tree is one of the “Three Trees” of Hainan, and it is cultivated in several cities and counties across the island. Rubber tree powdery mildew is a typical airborne fungal disease that occurs annually, severely affecting rubber yield and tree health. This study analyzed the potential airborne dispersal pathways of rubber tree powdery mildew spores from February 1, 2021, to March 31, 2023, with a focus on Baoting as the starting point for spore diffusion. Using the Lagrangian Hybrid Single-Particle Trajectory (HYSPLIT) model, airflow trajectories at various altitudes were simulated, and trajectory clustering analysis was performed with TrajStat software and the MeteoInfoMap platform to identify representative air mass transport paths. Results indicated that Baoting was the earliest outbreak area of rubber tree powdery mildew in Hainan, where airflows predominantly spreaded southwestward and northwestward, covering neighboring regions such as Sanya, Ledong and Wuzhishan. This suggests that spore dispersal via airflow may accelerate disease progression in the areas. Additionally, the study found that the spatiotemporal dynamics of spore spread primarily occurred from January to April each year, coinciding with the spring temperature and humidity conditions in Hainan and the phenological stages of rubber trees. The average budburst and disease onset times in Baoting preceded those in other regions, further the importance of Baoting as an early monitoring and warning site for powdery mildew in rubber trees. In conclusion, this study reveals the regional spatiotemporal transmission patterns of powdery mildew spores in Hainan island through the simulation and analysis of airborne spore dispersal from Baoting. The findings would provide scientific evidence and technical support for the formulation of targeted regional control measures, contributing to the effective management of powdery mildew and the stable development of Hainan’s rubber industry.

Xinglong coffee, a pillar of the local characteristic agriculture in Wanning, faces severe threats to its sustainable production from anthracnose. This disease can cause leaf scorching, branch ulcers, and berry brown rot, making it one of the major diseases in the industry. In this study, samples of coffee anthracnose were collected from the main coffee-growing areas in Wanning and the pathogenic fungi were isolated. The pathogenic fungi were identified through the combined analysis of multiple genes, including ITS, TUB2, CHS-1, ACT and GAPDH. Furthermore, a rapid detection system based on the loop-mediated isothermal amplification (LAMP) technique was established. 50 typical disease samples were collected, and through tissue separation and purification, a total of 24 Colletotrichum isolates were obtained. The pathogen population structure in the five planting areas of Wanning was clarified to comprise four species of Colletotrichum spp.: C. tropicale, C. karstii, C. fructicola, and the dominant species was C. siamense (accounting for 45.8%). Based on the specific region of TUB2, a specific LAMP primer set (Tub-L1) was designed and screened. The optimized reaction parameters were established as follows: isothermal amplification at 63 ℃ for 50 minutes, outer-inner primer concentration ratio of 8∶1, Mg²⁺ 8 mmol/L, dNTPs 0.8 mmol/L, and without the need for betaine. Validation experiments demonstrated that the detection sensitivity of this system reached 100 pg/μL (10 times higher than conventional PCR). Furthermore, the system showed no positive reactions to seven closely related species within Colletotrichum spp. (including C. tropicale, C. fructicola, C. karstii) or seven non-target plant pathogens [including Hemileia vastatrix (coffee leaf rust), Diaporthe phaseolorum, and others]. Using the optimized LAMP detection system, the diseased leaf samples collected from the field were analyzed. C. siamense was successfully detected in all samples, and the results were completely consistent with those obtained by conventional PCR methods. In summary, the LAMP-based rapid detection system for Colletotrichum sp. established and optimized in this study demonstrates significant advantages, including simplified operation, high reaction efficiency, strong specificity, enhanced sensitivity, and visualizable results, making it highly suitable for field-based rapid detection of C. siamense. This system would provide reliable technical support for the precise identification and efficient detection of coffee anthracnose fungus, and have important practical significance and application value for the early warning, disease monitoring, and integrated control of coffee anthracnose.

Odontoglossum ringspot virus (ORSV), one of the major pathogens affecting orchids, seriously degrade the ornamental and economic value of orchids by causing leaf chlorosis, mottling, and floral deformities. To enable early-stage diagnosis, this study developed a rapid reverse transcription-recombinase polymerase amplification (RT-RPA) assay targeting ORSV. Primers and a fluorescent probe were designed based on conserved regions of the ORSV coat protein (CP) gene. Specificity, sensitivity and field applicability of the assay were systematically validated in this study. Results identified F1/R1 as the optimal primer pair, enabling amplification within 20 minutes at 41 ℃. The method exhibited high specificity, distinguishing ORSV from Cymbidium mosaic virus and Cucumber mosaic virus, and achieved a detection limit of 2.8×10^–5 ng/μL total RNA. Practical verification result of 20 Phalaenopsis field samples showed 100% concordance with TaqMan qPCR results. The RT-RPA assay would provide a rapid, sensitive, and field-deployable tool for ORSV surveillance, supporting timely disease management and sustainable orchid cultivation. Its simplicity and reliability make it particularly valuable for large-scale screening in industrial orchid production systems.

Monascus is usually used in food and medical industries. To explore the biocontrol potential of Monascus and its secondary metabolites against plant biocontrol pathogens, in this study, through the isolation and identification of the fungi from humus samples in the rain forest, a total of five strains growing well on the potato dextrose agar medium were screened, the colonies were red, with typical Monascus morphological characteristics. The strains were identified as Monascus sanguineus based on the sequencing and analysis of ITS, LSU and pksKS gene sequences, The results of antagonistic experiments showed that the five strains of Monascus had better and more obvious inhibitory effects on Fusarium oxysporum f. sp. cubense, F. oxysporum f. sp. tracheiphilium, Phytophthora capsici, Colletotrichum gloeosporioides. After fermentation of Monascus with different media, high performance liquid chromatography (HPLC) and nuclear magnetic resonance analysis were carried out. It was found that Monascus could produce abundant secondary metabolites with strong antibacterial activity on solid medium, especially on wheat bran medium. The further pot experiment proved that Monascus could effectively reduce the wilt index of cowpea, and the best biocontrol effect was obtained when the spore concentration was 10⁶ CFU/mL. In summary, Monascus isolated from tropical rain forest showed good results of better biocontrol of plant diseases, and the secondary metabolites obtained by fermentation in rice medium had strong antibacterial activity, and could effectively control cowpea blight. Monascus strains isolated from tropical rain forest have great potential in plant disease biocontrol application, which can provide more abundant strains selection for plant disease biocontrol.

Cowpea aphids, two-spotted spider mites, and bean thrips are main pests during the cowpea seedling stage, severely impacting the growth and development of cowpea plants. To evaluate the safety and control efficacy of four seed coating treatments, 10% clothianidin flowable concentrate for seed treatment FS, 30% thiamethoxan FS, 600 g/L imidacloprid flowable concentrate for seed coating FSC and 8% fipronil FSC on three common pests during the cowpea seedling stage, this study conducted indoor pot experiments with insect infestations. The experiments aimed to evaluate the impact of the four seed coatings on cowpea emergence and the effectiveness in controlling cowpea aphids, two-spotted spider mites, and bean thrips. The results indicated that the germination rate of cowpea treated with 10% clothianidin FS, 30% thiamethoxan FS, 600 g/L imidacloprid FSC, and 8% fipronil FSC was 95.83%, 91.67%, 95.83% and 95.83%, respectively. The rate was slightly lower than that of the control (100%), but did not significantly affect crop growth. The findings revealed that 30% thiamethoxan FS exhibited the highest control efficacy against both cowpea aphids and bean thrips. Specifically, the control efficacy against cowpea aphids at 3, 7 and 14 days post-infestation was 65.04%, 81.10% and 72.35%, respectively. For bean thrips, the control efficacy at the same time points was 15.41%, 58.61% and 54.89%, respectively. As the infestation period progressed, the effectiveness of the seed coating treatments in controlling cowpea aphids and bean thrips gradually decreased. None of the four seed coating treatments demonstrated significant control efficacy against two-spotted spider mites. This research provides technical support for pest management during the seedling stage of cowpea production.

Evapotranspiration as a key component of the energy balance and hydrological cycle, not only plays an important supporting role in ecosystem stability and water resource management, but is also a crucial indicator for evaluating agricultural water use efficiency. Obtaining high spatiotemporal resolution data can reveal the dynamics of evapotranspiration, which is of great significance for analyzing ecological and hydrological processes. The region studied is rubber plantations in Danzhou city, Hainan province. Based on daily meteorological data from flux tower observations and ten corresponding scenes of Landsat 8 satellite imagery for the same period, the daily evapotranspiration of the rubber plantations in 2022 was estimated using the surface energy balance system (SEBS) model, and the results were validated for accuracy using the eddy covariance method. The results showed that the SEBS estimated daily evapotranspiration values from rubber plantations had a good correlation with the eddy covariance measured values (R²=0.88, RMSE=0.55, RE=18.95%). The daily evapotranspiration exhibited significant seasonal variation, showing that the wet season was significantly higher than the dry season. The maximum daily evapotranspiration occurred on July 31, reaching 4.40 mm, while the minimum daily evapotranspiration occured on January 28 and March 9, both at 1.38 mm. The accuracy of evapotranspiration derived from Landsat 8 imagery was influenced by factors such as vegetation cover and spatial heterogeneity. Therefore, the accuracy of the evapotranspiration varied with distance from the flux tower. Overall, the SEBS model showed the highest accuracy for rubber plantations within 1.5 km of the flux tower (RMSE=0.53, RE=18.08%), while it had the lowest accuracy for areas situated 1.0 km from the tower (RMSE=0.65, RE=22.26%). In conclusion, this study would provide a reference for improving the spatiotemporal resolution of evapotranspiration datasets, reveal the seasonal variability and spatial patterns of evapotranspiration in rubber plantations, and contribute to the development of effective water resource management and regulation policies in rubber plantation ecosystems.

Thioredoxins play critical roles in the maintenance of cellular redox homeostasis by regulating the structure and function of the target proteins through catalyzing thiol-disulfide exchange reactions. Previous research has confirmed that the y-type thioredoxin HbTRXy2 of rubber tree (Hevea brasiliensis) has a strong antioxidant function. To investigate the molecular mechanism of HbTRXy2 in enhancing antioxidant defense, a yeast two-hybrid library of rubber tree and the bait vector pGBKT7-HbTRXy2 for HbTRXy2 were constructed, and the interacting proteins of HbTRXy2 were identified via yeast two-hybrid in this study. The results indicated that the secondary library constructed in this study had a recombination rate of 100%, an average length of inserted fragments greater than 1000 bp, and a capacity of approximately 3.80×10⁶ CFU/mL. It was identified that the bait vector has no toxicity and self-activating activity in yeast and could be used for yeast two-hybrid screening. After testing, it was found that the bait vector had no toxicity and self-activating activity in yeast and could be used for yeast two-hybrid screening. Using the co-transformation method, 24 proteins interacting with HbTRXy2 were screened from the constructed library. Bioinformatics analysis revealed that the functions of the candidate interacting proteins encompassed redox processes, stress responses, ATP binding and metabolism, Calvin cycle, single-carbon metabolism, carbon fixation, methionine biosynthesis, lipid A biosynthesis, metal ion binding or transport, transmembrane transport, cell volume regulation, phosphate ion homeostasis, protein phosphorylation, protein folding, etc. The results would lay the foundation for further revealing the function and mechanism of HbTRXy2 in rubber tree.

Natural rubber is a key and widely used industrial raw material, which is mainly produced from Hevea brasiliensis. Cis-prenyltransferase (CPT) is an important component of natural rubber biosynthesis in laticiferous cells. It has been reported that HbCPT7 and HbCPT8 are specifically and highly expressed in latex, which is the cytoplasm of laticifers, and HblMYB19 and HblMYB44 can significantly promote the expression of HbCPT8 in tobacco and yeast. However, the transcription factors that regulate the specific expression of HbCPT7 in latex are still not clear. Here, we found there are several MYB- and MYC-binding sites located in promoter region of HbCPT7. We totally identified 226 HbMYBs and 19 HbMYCs in Hevea by using a genome-wide scanning approach. The transcriptome data showed that HbMYB1, HbMYB2, HbMYC1, HbMYC2, HbMYC3, HbMYC4 and HbMYC5 were highly expressed in latex. HbMYB1, HbMYB2, HbMYC1, HbMYC4 and HbMYC5 were successfully cloned from the latex of rubber trees. Through yeast one-hybrid assays, it was discovered that HbMYC5 could bind to the promoter regions of 1–1000 bp and 1501–1971 bp upstream of the start codon of HbCPT7. The results would provide a new insight into the molecular mechanism of HbCPT7 in regulating natural rubber biosynthesis.

Cassava (Manihot esculenta Crantz), the “king of starch”, is an important tropical food crop and a staple food for one billion people worldwide. Cassava vacuolar invertase (MeVINV1) is involved in plant growth and development and stress defense by irreversibly breaking down sucrose into glucose and fructose. Eight candidate proteins interacting with MeVINV1 were screened from the cassava SC8 cDNA yeast library by yeast two-hybrid experiment to explore the gene function and molecular regulatory network of MeVINV1. Furthermore, yeast point-to-point verification found that MeVINV1 interacted with MeUN-3, MeMTP1, MeCASP4A3 and MePIRL3, and the interaction with MeMTP1 was stronger. Therefore, it is speculated that MeVINV1 and MeMTP1 synergistically regulate vacuolar sucrose metabolism and metal ion transport, and participate in the regulation of cassava response to metal ion stress. The results of the study would provide a scientific basis for providing new genetic resources and molecular mechanisms of stress regulation in cassava stress resistance breeding.