The study explored the growth regularity and genetic variation characteristics of Aquilaria sinensis Qi Nan clones to provide a theoretical basis for selection superior A. sinensis Qi Nan clones and application. 25 A. sinensis Qi Nan clones cultivated in the Experimental Center of Tropical Forestry of the Chinese Academy of Forestry were inves-tigated, the tree height and basal diameter were measured at 1, 2 and 3 years, respectively. The study analyzed early growth performance, adaptability, growth trait variations among different clones, and the intercorrelations. Comprehensive estimation of genetic parameters and cluster analysis were used to select superior clones. There were significant differences in tree height, basal diameter and preservation rate among the clones. The average tree height, basal diameter and preservation rate at 3 years old was 134.15 cm, 2.89 cm and 68.40%, respectively. The highest was Qi NYH, and the lowest was Bo LZ. There were substantial variations in the annual growth increments of tree height and basal diameter among the clones. Generally, the tree height and basal diameter increased remarkably in the third year. The clones showed different ranges of variation in tree height and basal diameter at different growth stages. The basal diameter showed a high degree of dispersion and the richest variation. The broad-sense heritability of growth traits in 3 years was high and stable, above 0.63. Basal diameter, tree height and preservation rate showed significant or extremely significant positive correlation. Principal component analysis revealed that the clones were comprehensively evaluated and ranked based on the scores. According to the selection rate of 20%, the top five were Qi NYH, Ao S, Jin SZ, Tu YW and Cuan T in turn. The results of cluster analysis showed that the clones were divided into 4 categories. Class Ⅰ grew better, and had stronger potential for growth in the later period than others, including Ao S, Qi NYH, Lan BS, Tu YW, Jin SY, Xi GY, Jin SZ and Cuan T, with the tree height, basal diameter and preservation rate above 158.00 cm, 3.00 cm and 73.00%, respectively. Class Ⅱ and Class Ⅲ grew relatively fast. Class Ⅳ grew the slowest with the slowest tree height, basal diameter and preservation rate. Through comprehensive evaluation, Qi NYH, Ao S, Jin SZ, Tu YW and Cuan T clones had the best performance in tree height, basal diameter and preservation rate. They could be popularized and planted as the excellent comprehensive quality of A. sinensis Qi Nan clones in Pingxiang and other suitable places.

Aquilaria sinensis is the original plant of the precious traditional Chinese medicinal material known as agarwood, with a long history of medicinal application. Seeds play a crucial role in the reproduction process of A. sinensis. The seed is the recalcitrant type, with a short period of viability, cannot be dried in the sun nor stored for long periods. The quality assessment, storage, and germination of the seed are essential for obtaining high-quality seedlings. Additionally, the seed has various application beyond seedlings cultivation. Due to its rich content of various nutrients, high yield, and affordable price, it has numerous applications in medicine, food, feed, health products, and food additives. The article introduced the aspects of seed quality assessment, seed storage, seed development and germination, nutritional components, and application of A. sinensis seeds, and prospects for future research area, aiming to provide references for cultivating high-quality A. sinensis seedlings and the utilization of the seed.

Leguminous green manure cover cropping and incorporation play a crucial role in improving soil conditions and enhancing nutrient cycling in ecosystems. Studying the decomposition characteristics and nutrient release patterns of green manure is of significant importance for the sustainable production of rubber plantations. This study selected four representative tropical leguminous green manures: Pueraria phaseoloides Benth (GT), Crotalavia anagroides H.B.K (ZSD), Tephrosia candida DC. (SMD), and Stylosanthes guianensis (Aubl.) Sw. (ZHC). During the vigorous growth period of the green manures, a 260-day field in-situ decomposition experiment was conducted using the nylon mesh bag method to explore the decomposition characteristics and nutrient release patterns of the leguminous green manures from different genera. The dry matter decomposition characteristics followed the “Olson” exponential model. The decomposition constants (k) ranked as follows, GT (3.01)>SMD (2.51) and ZHC (2.36)>ZSD (2.01), with GT being significantly higher than ZSD (P<0.05). At the end of the experiment, the dry matter remaining rate of the four green manures was ZSD (24.7%)>SMD (22.7%)>ZHC (21.7%)>GT (17.3%). The time required for 95% decomposition was 17.9, 15.3, 14.3, and 11.9 months, respectively. For carbon (C), nitrogen (N), phosphorus (P), and potassium (K), the remaining rate across the four green manures (GT, ZSD, SMD, ZHC) was N (15.5%–34.0%)>P (11.9%–30.4%)>C (15.1%–22.2%)>K (0.58%–1.07%). Calcium (Ca) and magnesium (Mg) residue ratea was Ca (45.0%–64.0%)>Mg (11.5%–31.9%). Iron (Fe), copper (Cu), and zinc (Zn) showed average residue rate of 160.9%, 138.3%, and 110.6%, respectively, indicating enrichment effects, while manganese (Mn) had an average residue rate of 36.3%. Notably, GT exhibited complete nutrient release for all elements, with the lowest remaining rate among the four green manures. In contrast, ZSD, SMD, and ZHC demonstrated enrichment effects for Fe, Cu, and Zn. In conclusion, the differences in decomposition and nutrient release characteristics among green manures would provide critical theoretical support for nutrient cycling and soil fertility improvement in rubber plantations, and technical guidance for sustainable rubber plantation management.

40 newly developed domestic sugarcane varieties (lines) were used to screen sugarcane varieties with strong cold tolerance and excellent comprehensive traits in Quanzhou county, Guangxi. The results indicated that the value of plant height, stem diameter, millable stalk number, single stalk weight and cane yield of plant crop were higher than those in ratoon crop under natural low temperature conditions, with extremely significant difference observed in plant height, single stalk weight, and cane yield between plant crop and ratoon crop. There were significant or highly significant difference in plant height, stem diameter, millable stalk number, single stalk weight and cane yield among different varieties. Field brix, sucrose content and purity of plant crop and ratoon crop exhibited an ascending trend before the arrival of the first strong low-temperature weather, afterwards exhibited an declining trend. Stalk length damage rate (SDR) demonstrated a progressive increase across three survey periods in both plant crop and ratoon crop, but green leaves percentage (GLP) was gradually decreasing. Plant damage rate (PDR) differed among varieties initially, while in the second and third investigation, PDR reached 100% for all varieties. GT51, GT32, GT13-532, DZ09-78, GT58 and GT52 exhibited strong cold tolerance based on the the subordinate function method. The result from maximum entropy-minimum residual composite index model demonstrated that sugar content, cane yield and millble cane number in ratoon crop ranked the top three in weight coefficients, exerting significant impacts on the comprehensive evaluation of sugarcane varieties. DZ07-36, ZT1, ZZ6, YT07-913, FN38, DZ09-78, GT55, GT51, GT52, GT42 and GT58 showed overall superior performance and are suitable for promotion in colder northern sugarcane-growing regions.

It was aimed to understand the nutrient contents in soil and the characteristics of ecological stoichiometry in the main coffee producing areas of Yunnan Province, Baoshan, Pu'er, and Xishuangbanna. The nutrient content and ecological stoichiometry of both coffee soil and leaves were assessed, thereby enhancing our understanding of the interplay between crops and soil elements while also revealing the status of soil nutrient limitations. Among the regions studied, the C content in Baoshan soil was significantly lower than that of Xishuangbanna (P<0.05), and C/N ratio in Baoshan soil was notably lower than that of Xishuangbanna and Pu'er, while N/P ratio in Baoshan was significantly higher than that of Pu'er coffee. The C content of coffee leaves in Pu'er was more than that of both Baoshan and Xishuangbanna significantly. There were obvious differences in C content and C/N ratios among the leaves from the regions (P<0.01). Leaf N/P threshold analysis indicated that Pu'er coffee had an N/P ratio ranging between 14 and 16, suggesting growth constraints due to both N and P elements, while leaf N/P ratio exceeded 16 for Baoshan and Xishuangbanna coffees, indicating a restriction primarily by phosphorus. Correlation analyses revealed a highly significant positive correlation between C and N levels within coffee soils (P<0.01). Moreover, significant positive correlations were observed between leaf C with C/N ratio and C/P ratio (P<0.01), alongside a notable positive correlation between leaf carbon content and soil nitrogen levels (P<0.01). The results indicated that nitrogen and phosphorus were the limiting factors for Pu'er coffee cultivation and applying nitrogen and phosphorus in production is advisable. In contrast, phosphorus was the primary limiting factor for both Baoshan's and Xishuangbanna's coffees production, therefore, appropriate application of phosphorus should be recommended.

Coconut wood (Cocos nucifera L.), an economically significant tropical tree, exhibits variations in fiber morphology and chemical composition that directly influence its processing performance and comprehensive utilization potential. This study systematically investigated the spatial variability of fiber morphological indices (length, width, cell wall thickness, lumen diameter, aspect ratio, and cell wall-lumen ratio) and chemical components (holocellulose, cellulose, and lignin) across different trunk heights (bottom, middle, top) and radial positions (outer, middle, inner) in 40-year-old coconut trees from Hainan. The analyses were conducted using wood microscopy, image analysis software, and chemical assays. Fiber length (696.84–969.94 μm), cell wall thickness (9.78–18.36 μm), and cell wall-lumen ratio (1.13–5.82) decreased significantly from the bottom to the top, while lumen diameter (3.60–10.15 μm) increased. Fiber width (17.41–20.76 μm) and aspect ratio (40.39–48.79) showed minor variations but exhibited an overall downward trend with increasing height. Fiber length, cell wall thickness, and cell wall-lumen ratio decreased from the outer to inner regions, whereas lumen diameter increased. Chemical analysis indicated decreasing trends for holocellulose (59.14%–70.32%) and cellulose (41.03%–44.85%) content along both vertical and radial gradients, while lignin (21.40%–23.60%) initially decreased and then increased vertically, with higher inner-region content. The study identified superior fiber morphology (longer fibers, thicker cell walls, smaller lumen diameters) and higher holocellulose and cellulose content in the bottom and outer regions. Compared to bamboo, coconut fibers are thicker, with thicker cell walls and smaller lumens but lower aspect ratio, making them particularly suitable for medium-to-short fiber pulping processes. This research elucidates the spatial variation mechanisms of coconut wood fiber morphology and chemical composition, could providing a theoretical foundation for optimizing pulping, fiberboard manufacturing, and bioenergy applications, Such insights can enhance resource utilization efficiency and support sustainable development in tropical timber industries.

Sugarcane (Saccharum officinarum L.), a crucial sugar crop in China, faces yield and quality constraints due to soil nutrient limitations. Severe soil acidification and nutrient imbalances in the southwestern Yunnan sugarcane-growing areas hinder the sustainable development of the industry. This study aimed to clarify the driving effects of soil stoichiometric characteristics on sugarcane leaf nutrient uptake, identify critical thresholds for soil acidification and nutrient limitations, and provide theoretical and technical foundations for precision fertilization and soil improvement. Soil (0-30 cm depth) and leaf samples were systematically collected from 121 sugarcane fields across nine townships in Lianghe County, Yunnan Province using a grid-based sampling strategy. Soil parameters analyzed included pH, organic matter, total nitrogen, total phosphorus, total potassium, alkaline nitrogen, available phosphorus, available potassium, and DTPA-extractable micronutrients. Leaf nutrients (total nitrogen, total phosphorus, total potassium) were analyzed after H₂SO₄-H₂O₂ digestion. Structural equation modeling (SEM) was employed to construct multi-path networks linking soil fertility (organic matter, total N/P/K, available nutrients), micronutrients (Fe, Mn, Cu, Zn), and environmental factors (pH) to leaf nutrient dynamics. Model parameters were optimized via maximum likelihood estimation, with standardized path coefficients (β) and determination coefficients (R²) quantifying factor contributions. Soils exhibited pronounced acidification (mean pH=5.07), with 78.23% of samples ≤pH 5.5. Zinc deficiency (<1.5 mg/kg) occurred at 84.75% of sites, while TK (2.27%), available Fe (59.90 mg/kg), and available Cu (1.04 mg/kg) remained relatively high; Organic matter correlated strongly with TN (r=0.929^**), TP (r=0.614^**), AN (r=0.847^**), AP (r=0.642^**), and AK (r=0.399^**), indicating its central role in nutrient retention. Soil acidification (pH<5.5) reduced cation exchange capacity by 26.7% and negatively correlated with AN (r=–0.290^**). Neutral to slightly acidic conditions (pH 6.0–6.5) enhanced phosphorus and potassium availability. Soil available nutrients emerged as pivotal drivers of leaf nutrient assimilation. This study systematically illustrated the multi-path regulatory mechanisms of soil stoichiometric traits driving sugarcane leaf nutrient uptake in southwestern Yunnan's sugarcane belt, quantitatively linking acidification with nutrient dysregulation. It is proposed that an integrated fertilization strategy—“ameliorate acidity-supplement zinc-regulate nitrogen-enhance carbon” should serve as the technical paradigm for high-yield sugarcane cultivation and sustainable soil management, which also could be universally referred by the agricultural ecosystems in tropical and subtropical acidic soils.

Cymbidium ensifolium ‘Dongfang Honghe’, as a new cultivar of C. ensifolium, has an elegant posture and a distinctive pink-white colour, which is of high value for garden application. In order to deeply understand the flower formation rules of C. ensifolium, and to produce high-quality flowers to meet the demand of the holiday market, ‘Dongfang Honghe’ was used as the experimental material to elaborate the morphological change process of flower buds and flower development during the process of flower formation, and to study the effect of forchlorfenuron (CPPU) on its flowering period and blooming quality. The process of flower bud differentiation was divided into six periods according to the results of paraffin sections: floral primordial induction, inflorescence primordial differentiation, floral primordial differentiation, sepal primordial differentiation, petal primordial differentiation, as well as the stage of gynostemium and pollen block differentiation. The process of flower development was divided into six periods according to the characteristics of the morphology changes of inflorescences: the end of inflorescence bud differentiation, bract wrapping period, inflorescence elongation period, coloring period of flower buds, blossom period and flower wilting period. Spraying CPPU and cytokinin could advance the flowering period of C. ensifolium by about 1 month, among which 1 g/L CPPU+1∶1000 cytokinin had the best effect, and the treatment entered into the stage of flower development in 44 d. The flowering period was advanced by 26.55 d, and the duration of blooming was prolonged by 1.89 d compared with that of the control, and the flower buds increased by 0.54 per pot, and the scape diameter was thickened by 0.28 mm. It is assumed that CPPU stimulates the cell division of pseudobulbs, prompts their expansion, and then accumulates sufficient nutrients for the transformation of flower formation. In this study, the flowering process in ‘Dongfang Honghe’ was delineated, which provides key information for the subsequent in-depth study of the mechanism of flower formation to determine the sampling period and the prediction of flowering time in the industry. The effect of CPPU on the flowering of ‘Dongfang Honghe’ was investigated, which lays a theoretical basis for the establishment of a precise technical system of flower regulation.

In flowering plants, pollen grains land on the stigma surface, undergo hydration, and germinate to produce pollen tubes. Subsequently, the pollen tube grows through the stigma toward the ovule. Within the ovule, the pollen tube ruptures to release sperm cells. The two sperm cells fuse with the egg cell and the central cell, respectively, forming a diploid embryo and a triploid endosperm, thereby completing the double fertilization process. Pollen germination and pollen tube growth are crucial physiological processes in the sexual reproduction of flowering plants. The processes are of significant importance for the propagation of plant species and serve as the fundamental basis for the yield of grain crops. Calcium signaling, functioning as a critical secondary messenger, plays a central role in pollen germination and pollen tube growth. In plants, calcium signaling refers to the regulatory mechanism driven by dynamic changes in cytosolic calcium ion (Ca²⁺) concentrations. Calcium signaling serves as a key regulatory mechanism in plant cell signal transduction, involved in critical processes such as pollen grain perception of osmotic stress, germination, pollen tube growth, and guidance. Simultaneously, through modulating various pathways including calcium channels, calcium pumps, and calcium-binding proteins on the cell membrane, calcium signaling facilitates dynamic remodeling of the pollen tube cytoskeleton, thereby enabling pollen tube elongation and directional growth at the tip. Furthermore, calcium signaling coordinates with pathways involving auxin and abscisic acid to regulate pollen tube growth while promoting dynamic remodeling of the cytoskeleton and tip-focused growth through membrane-associated calcium channels and transporters. The review provides an in-depth exploration of the molecular mechanisms underlying calcium signaling in pollen germination and pollen tube growth, and its synergistic interactions with other signaling networks. These insights advance our understanding of plant reproductive biology and offer potential theoretical foundations for crop genetic improvement and agricultural innovation.

Annona squamosa L., a vital tropical fruit crop in southern China, faces escalating threats from fungal diseases, though rust pathogens had not been previously documented domestically. This study reported the first dectection of Phakopsora cherimoliae, a high-risk rust fungus known to cause severe yield losses (>30%) in Central and South America, detected in Yunxiao county, Fujian province. Field symptoms included chlorotic flecks on adaxial leaf surfaces progressing to reddish-brown necrotic lesions with abaxial yellowish-brown uredinia. Morphometric analysis revealed ellipsoid to ovoid urediniospores, long axis is (28.0±2.5)μm; short axis is (22.7±3.2)μm, consistent with P. cherimoliae descriptions but notably smaller than those reported on A. cherimola hosts, suggesting potential host-driven morphological adaptation. Molecular characterization via LSU rDNA sequencing indicated that the sequence of the three isolates obtained in this study exhibited over 99% identity with the reference strain KF528012. Phylogenetic analysis using maximum likelihood and the Kimura-2 parameter method positioned the isolates in a distinct monophyletic clade with 100% bootstrap support, separate from other related Phakopsora species. Pathogenicity was confirmed through Koch's postulates. Inoculation of healthy Annona trees with filed urediniospores induced identical symptoms and new urediniospores within 14 days. The absence of telia indicated dependence on urediniospores for asexual propagation, raising concerns about persistent epidemics under Fujian's humid subtropical climate, where monsoon winds may facilitate regional dispersal. Urgent management strategies include pre-monsoon application of tebuconazole, systematic removal of infected debris, and resistance screening across commercial cultivars (e.g., ‘African Pride’). Study limitations include unresolved telial stage biology and unquantified spore dispersal dynamics, warranting long-term phenological monitoring and aerobiological modeling. This invasion event underscores vulnerabilities in China's tropical fruit biosecurity, emphasizing the imperative for enhanced phytosanitary surveillance and international collaboration to mitigate cross-border pathogen spread. The findings establish a critical baseline for rust disease management in Asian Annona production systems, bridging a longstanding gap in regional plant pathology literature.