The induction of adventitious roots (AR) is a key step for successful clonal propagation in plants. Previous studies have shown that the auxin polar transport carrier MiPIN1 plays an important role in AR formation from mango cotyledon segments, yet its upstream regulatory mechanisms remain unclear. In this study, a 2 112 bp promoter sequence of MiPIN1 isolated using FPNI-PCR. Bioinformatic analysis revealed that the promoter region contained various cis-acting elements, including those involved in light response, MYB binding, abscisic acid response, and low-temperature stress. A bait vector, pAbAi-MiPIN1, was constructed, and the minimal concentration of Aureobasidin A (AbA) required to suppress autoactivation in the yeast system was determined to be 500 ng/mL. Furthermore, a yeast cDNA library was constructed from mango cotyledon segments during AR formation. Using the yeast one-hybrid (Y1H) system, 62 upstream proteins that potentially bind to the MiPIN1 promoter were identified, including auxin-binding protein ABP19a-like, zinc finger protein CCCH, MYB308, 8-hydroxygeraniol dehydrogenase, and chlorophyll a-b binding protein LHCII. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses indicated that the proteins were mainly involved in biological processes such as cellular processes, metabolism, response to stimuli, and biological regulation. They were also enriched in metabolic pathways related to secondary metabolite biosynthesis, energy metabolism, and the metabolism of amino acids, lipids, and carbohydrates. The findings would lay a foundation for unraveling the molecular regulatory network underlying adventitious root formation in mango.

Sugarcane is a globally important cash crop and bioenergy crop, playing a critical role in promoting economic development in sugarcane-producing countries. Phosphorus is an essential nutrient for plants, and low phosphorus availability in soil often constrains the quality and yield of sugarcane in China. S. officinarum serves as an important genetic foundation for modern sugarcane varieties. Elucidating the low-phosphorus tolerance mechanisms in phosphorus-efficient genotypes of S. officinarum is of significant theoretical and practical importance for screening and breeding phosphorus-efficient sugarcane varieties, improving phosphorus fertilizer utilization efficiency, and promoting the development of the sugarcane industry. The study was aimed to explore the response characteristics of different S. officinarum genotypes under low-phosphorus stress from the perspectives of root morphology and physiological adaptations, identify key factors affecting phosphorus absorption, and provide a theoretical basis for improving nutrient utilization efficiency in sugarcane through root plasticity modification. Phosphorus-efficient S. officinarum genotypes (48 Mouna and Loether) and phosphorus-inefficient genotypes (NC20 and Badila) were used in the study. Under two phosphorus supply conditions, low phosphorus (0.2 μmol/L KH₂PO₄) and normal phosphorus (1000 μmol/L KH₂PO₄), comparative analyses were conducted on root morphological indices, low-phosphorus tolerance indices, root activity, acid phosphatase activity, and other physiological characteristics of each variety. The results indicated that low-phosphorus stress could inhibit the growth and development of various sugarcane tropical varieties to different degrees. Among them, the phosphorus-efficient variety Loether was the least affected by low-phosphorus stress in terms of plant height, stem dry weight, and whole-plant biomass, while its root dry weight and root-to-shoot ratio significantly increased. Low-phosphorus stress promoted increases in total root length, total root surface area, and total root volume in both Loether and 48 Mouna, with Loether exhibiting the most pronounced increase. The specific root length, specific root surface area, and specific root volume of most varieties decreased, with NC20 showing the greatest reduction. Additionally, all varieties exhibited root thinning. Furthermore, under low-phosphorus stress, 48 Mouna and Loether demonstrated higher root low-phosphorus tolerance indices, root activity, and phosphorus acquisition capacity. In conclusion, this study reveals that the phosphorus-efficient tropical varieties 48 Mouna and Loether can better optimize root architecture, enhance phosphorus absorption interfaces, maintain strong root activity and enzymatic adaptability, effectively improve phosphorus absorption and utilization efficiency, and exhibit strong adaptability to low-phosphorus stress.

Lodging resistance is an important trait in sugarcane breeding. Accurate evaluation of the lodging resistance of germplasm resources is of great significance for breeding lodging-resistant varieties. This study investigated the effects of agronomic traits and stalk fiber components on lodging resistance using 16 sugarcane germplasm materials. The key traits affecting lodging resistance were identified by grey correlation analysis, and the comprehensive evaluation was carried out by using membership function method and cluster analysis method to screen excellent lodging resistance germplasm and its key traits, so as to provide germplasm resources and theoretical reference for sugarcane lodging resistance breeding. The results showed that the sugarcane germplasm materials with the strongest lodging resistance were Yunzhe 17501, Guiliu 05136 and Yuetang 93159. Among them, stem diameter, effective stem number, plant height and cellulose content were the key factors affecting the lodging resistance of sugarcane.

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.

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.

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 purpose of this study was to investigate the mechanism and efficacy of Lvnonglin ^®41 compound microbial fertilizer in mitigating black pepper continuous cropping obstacles from the perspectives of soil nutrients, microbial community structure and diversity, so as to provide technical strategies for the industrial cultivation of black pepper in Hainan. Field experiments were conducted on a plot with a history of severe black pepper Fusarium wilt. Four treatments were designed: water control (CK), Lvnonglin^® 41 compound microbial fertilizer (LNL41), compound microorganisms (CM), and bacterial fertilizer nutrient substrate (NS). The incidence of Fusarium wilt in the rhizosphere, plant growth and soil nutrients were measured. Using 16S rDNA sequencing technology, the differences in the occurrence of black pepper Fusarium wilt and the bacterial community structure in the rhizosphere soil under LNL41 application were explored. The results showed that compared with CK, all treatments exhibited certain effects, with the LNL41 treatment being the most effective. Soil nutrient indicators in the LNL41 and CM treatments were significantly higher than those in CK. The increases in chlorophyll content, spike length and 1000-grain weight under LNL41, CM and NS treatments reached 26.12%–67.87%, 6.20%–18.33% and 1.48%–6.44%, respectively. The incidence rates at different growth stages in the LNL41 treatment were 2.67%–15.67%, with control efficacies of 81.64%–90.06%. The Ace and Chao1 indices of rhizosphere soil bacteria increased by 12.82%–20.28% and 12.89%–18.78%, respectively, and the Shannon diversity index increased by 1.05%–3.53%, while the Simpson index showed no significant difference among treatments. At the order level, Chitinophagales, Rhizobiales and Burkholderiales were the dominant bacterial orders. At the genus level, Gaiella, P3OB 42, Lactobacillus, Pseudolabrys and Terrimonas were the dominant bacterial genera. The abundances of the common dominant genus Bacillus and Candidatus Omnitrophus were similar across treatments. Linear discriminant analysis (LEfSe) results indicated the presence of six indicator bacterial taxa in the LNL41 treatment. Ellin6067 and Tepidisphaera showed significant or highly significant positive correlations with soil pH, organic matter, available potassium, ammonium nitrogen and available phosphorus. Network analysis further revealed that the LNL41 treatment enhanced the complexity and stability of the soil bacterial co-occurrence network. Bugbase functional prediction demonstrated that the abundance of stress tolerant functional groups in the LNL41 treatment increased by 5.38 percentage points, while it decreased by 10.43 and 7.25 percentage points in the CM and NS treatments, respectively. LNL41 significantly improved the ratio of soil nutrients, thereby enhancing the structure and functional characteristics of the soil bacterial community, stimulating bacterial stress tolerance functions, promoting black pepper growth, and reducing the incidence of Fusarium wilt.

Intercropping within rubber plantations presents an effective strategy to counteract the financial challenges posed by sustained low prices of natural rubber and widespread cultivation losses. The success of the intercropping systems is critically dependent on understory light availability, which serves as a key driving factor. A thorough analysis of the variations in understory light conditions among different rubber clones and the underlying causes is essential for providing a theoretical basis for optimal clone selection and system design. This study investigated rubber plantations featuring various clones, tree ages, and planting patterns. The understory light intensity were measured and compared. Unmanned Aerial Vehicle LiDAR point clouds were used to extract key tree architecture parameters to determine the architectural drivers of light variability. Findings revealed significant differences in understory light intensity attributable to clone type, tree age, and planting pattern. Notably, the Reken 628 clone consistently provided significantly higher understory light levels across all ages and row orientations compared to other clones like CATAS 72059, and CATAS 73397. UAV-derived data confirmed that Reken 628 plantations exhibited larger inter-row gaps and significantly lower canopy closure. Architectural analysis further elucidated that Reken 628 was characterized by a taller stature, higher branching, a smaller crown length ratio, and a more compact, sparser crown structure with fewer, smaller-angled primary branches. This clone also displayed pronounced natural self-pruning, which collectively contributes to its low canopy closure. Conversely, CATAS 73397 features a wider crown, a higher crown length ratio, more numerous and wider-angled branches, and severe crown overlap, resulting in high canopy closure. In conclusion, considering its favorable tree architecture and the resultant superior light conditions, Reken 628 is identified as an excellent clone for intercropping systems. This research holds significant practical value for advancing the adoption and sustainable development of intercropping in rubber plantations.

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.

Hainan Island possesses unique ecological conditions that nurture abundant wild tea resources. This study systematically investigated the distribution patterns and growth models of wild tea trees in Hainan through literature review and field surveys. Curvilinear regression analysis was employed to establish growth relationships among tree height (H), crown width (P), diameter at breast height (DBH, D), and basal diameter (d). Wild tea populations are distributed in Wuzhishan City, Baoting County, Qiongzhong County, Baisha County, Ledong County, and Lingshui County, spanning longitudes 108.85°E–109.91°E, latitudes 18.21°N–19.19°N, and elevations 357.0–1410.6 m. The population primarily occur in secondary forests and cultivated tea gardens, with significant canopy density fluctuations. The wild tea tree resources in the study area were mainly distributed in sheets, and 6915 wild tea trees were preliminarily investigated in 6 cities and counties, and the area with the largest number of wild tea trees was Wuzhishan, with a total of 4461 trees, accounting for 64.51% of the total. Wild tea tree diameter structure showed a normal distribution characteristic with grade II seedlings accounting for the main body (40.68%), followed by grade I seedlings (25.29%), and only 2.22% of the V–VI. large-diameter wild tea trees remaining, showing an obvious juvenile structure. Maximum crown width (11.5 m) and tree height (26.0 m) were recorded in Wuzhishan City, alongside the highest coefficients of variation for crown width (56.53%) and height (53.87%), with a crown-to-height ratio of 0.62. Optimal cubic regression models for growth relationships were: H=0.614+0.014C-0.258C²+2.13C³ (R²=0.488, h<700 m); H=1.949-0.001D+0.020D²+0.248D³ (R²=0.340, 700 m≤h<1300 m); D=-0.726+0.001d-0.024d²+1.026d³‌ (R²=0.887, h≥1300 m). The research would provide critical data for ecological monitoring in Hainan Tropical Rainforest National Park, tea germplasm conservation, and green certification of tea industries. It also would advance carbon sink management under China’s carbon neutrality goals and highlights the urgency for scientific conservation and sustainable utilization of wild tea resources to enhance biodiversity and regional socioecological resilience.