Tropical mountain ecosystems are vital repositories of medicinal plant resources, and understanding the altitudinal distribution patterns is crucial for sustainable resource utilization, biodiversity conservation, and research into environmental drivers of medicinal bioactive compounds. To elucidate the altitudinal distribution patterns of the medicinal plants in Wuzhishan Mountain, Hainan, this study conducted quadrat surveys across different elevation gradients (low: 200–400 m; mid: 400-600 m; mid-high: 600-800 m; high: 800–1100 m), documenting 447 species from 260 genera and 99 families, with angiosperms comprising 93.51% of the total species. Tropical families and genera accounted for 83.35% and 86.55%, respectively (excluding cosmopolitan elements), while temperate components increased significantly with elevation. Angiosperms dominated across all elevations, whereas ferns, initially comprising only 1.80% at low elevations, increased significantly to 4.79% and 6.50% at mid-high and high elevations, emerging as a key group. The comprehensive importance value of the tree layer exhibited a bimodal distribution, with dominant species transitioning from tropical at low elevations to temperate transitional species at high elevations, reflecting a tropical-to-temperate floristic shift. The shrub layer’s importance value fluctuated downward with elevation, indicating a synergistic response to the overlying tree structure, while the herb layer shifted from shade-tolerant herbs to medicinal ferns with increasing elevation. α-diversity analysis revealed that tree layer species richness and Shannon diversity peaked at mid-high elevations, aligning with the “mid-domain effect”, while herb layer diversity peaked at mid-elevations, with Simpson dominance significantly higher than in the tree and shrub layers. β-diversity indicated that tree layer species turnover was driven by hydrothermal gradients, whereas shrub and herb layers were primarily influenced by microhabitat heterogeneity. In summary, this study systematically elucidated the vertical distribution patterns of medicinal plants in Wuzhishan Mountain, providing a theoretical foundation for the conservation and utilization of tropical mountain medicinal plant resources and insights into the environmental drivers of medicinal plant quality. Future research should focus on ecological factor analysis in the mid-high elevation (600–1100 m) fern-rich zones.

Camellia oleifera is an important woody oil crop in southern China. Due to its generally weak disease resistance, it is susceptible to various diseases, among which southern stem blight is one of the major threats to its production. This study systematically screened and analyzed the non-volatile metabolites produced by Trichoderma semiorbis FJ059 with antagonistic activity against Sclerotium rolfsii, the causal agent of southern blight in C. oleifera, and identified the potential antifungal components. The antagonistic effects of non-volatile metabolites produced in different solid-state fermentation media were compared using the growth rate method of mycelia. Results indicated that rice was the optimal substrate, yielding the highest antagonistic effect (99.61%). The solid-state fermentation products in rice media were extracted using different solvents. The ethyl acetate extract exhibited significantly higher inhibition activity than the aqueous extract. When the concentration was 500 μg/mL, the inhibition rates was 98.84% and 44.18%, respectively, indicating that the solvent selection play a vital role in the extraction of active compounds. LC-MS analysis identified several key active substances in the ethyl acetate extract, including nootkatone, caryophyllene oxide, farnesol, pyrrole-2-carboxylic acid, and trans-ferulic acid, all of which demonstrated significant antagonistic effects against S. rolfsii. Notably, the inhibition rate of 200 μg/mL nootkatone and 300 μg/mL caryophyllene oxide were both 100%, while 400 μg/mL farnesol, 400 μg/mL pyrrole-2-carboxylic acid, and 400 μg/mL trans-ferulic acid were 78.30%, 69.38% and 69.77%, respectively. The results indicated that medium-polarity or hydrophobic small molecules in the solid-state fermentation products of T. semiorbis FJ059 were potential antifungal components. The results indicated that the medium-polarity or hydrophobic small molecules detected in the ethyl acetate extract of solid-state fermented T. semiorbis FJ059 were closely associated with antifungal activity, suggesting that the ethyl acetate extract may enrich certain compounds with antifungal potential. The findings would provide new theoretical support and bioactive compound resources for the development of novel and efficient biocontrol agents against southern blight in C. oleifera.

0, 60 and 120 kg/hm² MgO treatments (denoted by Mg0, Mg60, and Mg120, respectively) on a long-term wax gourd (Tiezhu No.2) magnesium (Mg) fertilizer gradient positioning experiment was conducted in 2022 and 2023 to investigate the physiological mechanism of Mg to improve the storage resistance of wax gourd fruits by regulating pectin metabolism by measuring indicators such as fruit hardness, weight loss rate, Mg content and morphology, pectin content and morphology, and pectin metabolic enzyme activity during fruit storage. Results showed that wax gourd yield increased by 8.5% to 16.9% after Mg fertilization, with the Mg60 treatment showing the greatest increase. Compared with the Mg0 treatment, the flesh hardness of the Mg60 treatment increased by an average of 12.9%, 11.7%, and 18.9% in the two years of 0, 30, and 60 d storage, while the Mg120 treatment showed a significant difference from the Mg0 only after 30 days of storage in 2022. Suitable Mg fertilization delayed the rise of the fruit storage weight loss rate. The fruit storage weight loss rate of Mg60 after 60 d was 34.4% and 35.1% lower than that of Mg0 and Mg120 treatment. Magnesium fertilization significantly increased fruit Mg content. Alcohol-soluble (Mg_Eth), water-soluble (Mg_Wat), and salt-soluble Mg (Mg_NaCl) were the main forms of Mg in the fruit. The content gradually increased with the prolongation of storage time. During fruit storage, the total pectin content gradually decreaseg. However, appropriate Mg fertilization (Mg60) delayed the decline in water-soluble (WSP), ion-bound (CSP), and covalently bound pectin (SSP) content, thereby maintaining the total pectin content. Suitable Mg fertilization (Mg60) inhibited the activity of polygalacturonase (PG) and β-galactosidase (β-Gal), thereby slowing down the degradation process of pectin. Concurrently, it increased pectin methylesterase (PME) activity and the content of free Mg²⁺ (MgEth and MgWat), enabling negatively charged pectin acid to bind with Mg²⁺, thereby increasing CSP and SSP. This slowed the rate of hardness decline and weight loss caused by pectin degradation during fruit storage. Comprehensively, suitable Mg (60 kg/hm²) fertilization can improve the storage resistance of wax gourd by regulating pectin metabolism, which is conducive to optimizing the Mg of wax gourd, improving the storage quality, and promoting the sustainable development of the industry.

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.

The fruit of rambutan has a delicate and juicy taste, but it is not resistant to storage. It is prone to browning 2-3 days after harvest, which limits the market circulation of rambutan. Therefore, green, safe and convenient post-harvest preservation technology is very important for the development of the rambutan industry. The purpose of the study was to explore the effects of exogenous sodium nitroprusside (SNP) treatment on the browning of postharvest rambutan peel and its active oxygen metabolism, and to provide new ideas for the browning of postharvest rambutan. The Baoyan 7 rambutan was soaked with 200 μmol/L SNP, and the control was treated with distilled water. The weight loss rate, browning index and antioxidant enzyme activity of rambutan during storage were measured. The results showed that SNP treatment could effectively inhibit the increase of browning index of postharvest rambutan peel and maintain the peel color. Compared with the control group, the activity of reactive oxygen species (ROS) scavenging enzymes [superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX)] was significantly increased in the peel of rambutan treated with SNP, which improved the scavenging ability of reactive oxygen species radicals in the peel. The activities of polyphenol oxidase (PPO) and peroxidase (POD) were lower than those of the control, which effectively inhibited the occurrence of enzymatic browning. In addition, compared with the control group, SNP treatment can also significantly inhibit the increase of membrane lipid degradation-related enzyme activity (lipoxygenase, LOX) and maintain the structural integrity of pericarp cells. At the same time, the expression levels of browning-related genes NlWRKY23 and NlWRKY57 was significantly up-regulated. This shows that SNP treatment can enhance the antioxidant capacity of the peel of rambutan, reduce the oxidative damage of reactive oxygen species (ROS), and delay the occurrence of peel browning. The results of this study can provide theoretical basis and practical basis for the application of SNP in postharvest rambutan.

The absence of standardized protocols for harvesting green betel nut fruits has led to significant inconsistencies in the quality of fresh produce. Therefore, this experiment used Hainan betel nuts as the test material, sampling every 30 days starting from 30 days after fruit setting, measuring the developmental dynamics of fruit phenotype and inclusions, exploring the development law of betel nut fruits, and determining the optimal harvesting period for green betel nuts. The fruit shape index showed a trend of first increasing and then decreasing, with a variation range of 1.69-1.87. Among them, when the fruit developed to 120 days (1.79)-150 days (1.61), the fruit shape index met the first-grade standard, presenting a long elliptical shape. The chlorophyll content was high at 120-180 days, and the fruit color was emerald green. The pulp hardness showed a trend of first increasing and then decreasing, with a variation range of 85.2-274.49 gf. The hardness at 120-150 days was lower than the average (197.34 gf), meeting the first-grade standard. The soluble sugar contents in both the pulp and kernel showed a trend of first increasing and then decreasing, with variation ranges of 1.23%-4.47% and 5.56%-7.12%, respectively. The soluble sugar contents in the pulp and kernel were high at 120-180 days. The arecoline contents in both the pulp and kernel showed a gradual decreasing trend, with variation ranges of 3.55%-0.19% and 3.42%-0.40%, respectively. The arecoline content in betel nut fruits reached a relatively high level at 120-180 days. After standardizing the data for several key nodes and performing Principal Component Analysis (PCA), the comprehensive score of the pulp and kernel was the highest (1.18) at approximately 150 days after flowering. Combining the variation laws of fruit phenotype and internal quality, the optimal harvesting period for green betel nuts is approximately 150 days after fruit setting.

Eotetranychus sexmaculatus Riley is an important pest mite on rubber trees, it causes damage to rubber leaves, causing localized chlorotic spots to spread to the entire leaf, resulting in severe yellowing. Severe infestations result in massive leaf drop, disrupting normal tapping operations and leading to yield losses. However, the changes in physiological and biochemical indicators of rubber tree leaves after mite damage, and the relationship with mite population density and infestation duration, remain unclear. This study aimed to reveal the effects of varying mite densities and infestation durations on physiological and biochemical traits in rubber tree leaves, and to elucidate the defense mechanisms of rubber trees, thereby providing a theoretical basis for mite monitoring and early warning and precise prevention and control of the mite. In this study, the effects of malondialdehyde (MDA), soluble sugars, soluble proteins and protective enzymes (SOD, POD, CAT) activities on the leaves of rubber trees with different infestation times were determined on the rubber potted seedlings of the same length of Thermo Scientific 7-33-97 rubber seedlings inoculated with different mite densities in the greenhouses. The two-way analysis of variance (ANOVA) was used to reveal the interaction between mite population density and infestation time. Regarding membrane lipid peroxidation damage, both mite population density and infestation duration significantly influenced MDA content, exhibiting an initial increase followed by a decrease as infestation time prolonged. MDA levels peaked at (73.91±1.89)nmol/g after 15 days of treatment with 40 mites per leaf, representing a 43.15% increase compared to the control. MDA levels began to decline to (65.09±0.29)nmol/g after 20 days. Both soluble sugar and soluble protein contents decreased with increasing mite density and duration of infestation. At a mite density of 40 mites/leaf with 20 days of continuous feeding, soluble sugar and soluble protein contents reached the lowest values at (34.42±1.43)mg/g and (17.74±0.63)mg/g, respectively, representing significant decreases of 44.20% and 45.30% compared to the control. In response to mite-induced oxidative stress, the protective enzyme activities (SOD, POD, CAT) in rubber tree leaves generally showed a significant upward trend during the early stages of mite infestation across different mite density and duration treatments. Enzyme activity peaks occurred earlier under high mite density treatments (30 mites/leaf and 40 mites/leaf). Specifically, SOD activity peaked at (13 086.92±613.39)mg/g after 5 days of 40 mites/leaf infestation, representing a 91.74% increase compared to the control. POD activity reached minor peaks at 10 days post-infestation in both 30 and 40 mites/leaf treatments (6293.13±80.75)U/(min·g) and (6655.54±51.44)U/(min·g), respectively, followed by a decline before rising again. CAT activity peaked at 10 days in the 40 mites/leaf treatment (165.77±0.41)µmoL/(min·g), representing a 62.74% increase compared to the control. Interaction analysis revealed that the interaction between mite density and damage duration significantly affected soluble sugar content (F=21.296, P<0.001), soluble protein (F=17.782, P<0.001), and significantly affected SOD (F=20.252, P<0.001), POD (F=9.821, P<0.001), and CAT (F=145.095, P<0.001) activities. Both the mite population density and the duration of damage inflicted by the E. sexmaculatus leaf mite can influence the physiological and biochemical indicators in rubber tree leaves, including malondialdehyde, soluble sugars, soluble proteins, and protective enzymes (SOD, POD, CAT). Furthermore, a significant interaction exists between mite population density and duration of damage (P<0.001). This confirms that stress intensity and duration do not act independently, but they jointly determine the physiological damage degree, nutritional status, and antioxidant defense efficiency of rubber tree leaves through a complex synergistic mechanism.

The study was aimed to explore the changes of basic nutrients, active substances and antioxidant activity of the Macadamia flowers in the bud swelling period, early flowering, and full-flowering stages, and provide the basis for its development and utilization. The changes of basic nutrients, active substance content and antioxidant activity of the Macadamia flowers at the bud swelling period, early flowering stage and full-flowering stage were systematically analyzed. The results showed that among the basic nutrients of the Macadamia flowers at three flowering stages, the water content showed a decreasing trend [the highest at the bud swelling period was (70.99±2.58)%]. Soluble protein was the highest (0.054±0.009)% in the bud swelling period. Crude fat increased first and then decreased [the highest was (2.20±0.021)% at early flowering]. The total ash content decreased first and then increased [the highest was (3.73±0.02)% at full-flowering stage]. The early flowering stage of total sugar was the highest (1.65±0.19)%. It contained 16 abundant amino acids (7 essential amino acids and 9 non-essential amino acids), and the total amino acid content decreased with the development of flowering period. The proportion of essential amino acids and E/N value were close to the international high-quality protein standard, showing good protein nutritional value. In the Macadamia flowers at different flowering stages, the contents of five major elements in the three flowering stages showed the order of K>Ca>P>Mg>Na, highlighting the advantages of high K and low Na. The content of K at full-flowering stage was 5.2 times that of banana, and the content of Ca was 5.0 times that of milk. However, as a food development, it is necessary to pay attention to the risk of excessive As, Cr and other harmful elements. A total of 22 (the bud swelling period), 14 (early flowering stage) and 20 (full-flowering stage) volatile components were identified, mainly hexanal and d-limonene, which together constituted its unique floral characteristics. The analysis of active components showed that the content of total polyphenols decreased significantly with the prolongation of flowering period, and the bud swelling period was (18.47±2.3)mg/g. The content of total flavonoids increased first and then decreased, and the content was the highest in the early flowering stage, reaching (8.09±0.63)mg/g. The antioxidant activity evaluation showed that the DPPH and ABTS free radical scavenging rates were the highest in the bud swelling period, which were (89.96±0.61)% and (99.50±0.22)%, respectively, and the antioxidant capacity was strong. In summary, the Macadamia flowers are rich in amino acids, minerals and active substances from the bud swelling period to the full-flowering stage, and have high antioxidant capacity, which provides a scientific basis for their subsequent development and utilization.

Date palm, a member of the palm family, is dioecious with highly heterozygous genes and severe trait segregation. The propagation of its seedlings depends on asexual reproduction. Tissue culture technology is currently the main approach to realize the commercial production of date palm seedlings. However, the low germination rate of somatic embryos and the long period of seedling formation lead to difficulties in system construction and high tissue culture costs. Therefore, studying the physiological responses of date palm to adventitious bud induction regulated by hormones and optimizing the adventitious bud induction system are urgent tasks. Based on the previous screening of explant types of date palm, an orthogonal experimental design was used to optimize the induction of callus and embryogenic callus. By screening and proportioning the types and concentrations of plant growth regulators in the MS medium, adventitious buds were induced from somatic embryos. The germination rate of adventitious buds and the induction time of buds were statistically analyzed. Date palm adventitious buds obtained under different hormone levels were sampled, and the morphological change patterns of adventitious buds were observed. The change patterns of antioxidant enzyme activities (peroxidase, superoxide dismutase, glutathione reductase, catalase), hydrogen peroxide content, and other indicators in the samples were determined. The results indicated that the bud induction rate was P₈>P₆>P₅>P₄. The highest bud induction rate was achieved under the P₈ (MS+30 g/L sucrose+3 mg/L NAA+2 mg/L 6-BA+1 mg/L KT) treatment. The shortest bud induction time was under the P₆ (MS+30 g/L sucrose+2 mg/L NAA+3 mg/L 6-BA+1 mg/L KT) treatment. The highest activity of glutathione reductase was under the P₈ treatment. The coefficient of variation was the largest for the activity of glutathione reductase, and the range was the largest for the activity of superoxide dismutase. Principal component analysis revealed that the cumulative contribution rate of the first three principal components reached 94.614%. The eigenvalue of the first principal component was 2.365, with a contribution rate of 50.729%. In the first principal component, the activities of glutathione reductase, catalase, and peroxidase jointly affected, among which the eigenvalue of the activity of glutathione reductase was the largest at 0.821, mainly reflecting the influence of the activity of glutathione reductase on adventitious bud induction. The results of the study would provide a theoretical basis for optimizing the adventitious bud induction system and lay a technical foundation for achieving efficient and rapid propagation of date palm.

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.