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.

In this study, Cymbopogon winterianus was used as the experimental material, and the DNA sequence of C. winterianus was sequenced using the Illumina NovaSeq 6000 sequencing platform. The sequencing data were assembled with GetOrganelle v1.7.7.0 software to construct the chloroplast genome. Referring to the known chloroplast genome of C. flexuosus, the chloroplast genome of C. winterianus was annotated, and the genomic characteristics were analyzed and a phylogenetic tree was constructed. The chloroplast genome of C. winterianus was 139 823 bp in length, with a typical circular quadripartite structure. The GC content was 38.45%, and the AT content was 61.55%. It included a large single-copy region (LSC) with a length of 82 214 bp, a pair of inverted repeat regions (IR) with a length of 21 368 bp, and a small single-copy region (SSC) of 14 873 bp. A total of 130 genes were annotated in the chloroplast genome of C. winterianus (including 85 mRNA genes, 37 tRNA genes, and 8 rRNA genes). In addition, among the annotated genes, there were 16 double-copy genes, accounting for 12.31%, including 7 tRNA genes, 4 self-replication genes, 4 rRNA genes, 2 protein genes with unknown functions, and 1 NADH dehydrogenase subunit gene. A total of 144 SSR loci were detected in the chloroplast genome of C. winterianus, with mononucleotide repeats being absolutely dominant, mainly A/T. After comparing the boundaries of the inverted repeat sequences of four Cymbopogon species, it was found that C. flexuosus, C. pospischilii, and C. winterianus exhibited extremely high homology in gene structure and species. Among them, the ndhH gene was located in the small single-copy region (SSC), and the ndhF gene was located in the boundary region between the SSC and IRb. However, C. winterianus had an additional rps3 gene in the LSC region compared with C. flexuosus and C. pospischilii. Phylogenetic tree analysis showed that C. winterianus had the closest genetic relationship with C. pospischilii and C. citratus (MK593547.1). This study completed the assembly and annotation of the complete chloroplast genome of C. winterianus, analyzed the characteristics of the chloroplast genome of C. winterianus, and preliminarily explored the phylogenetic position of C. winterianus within the genus Cymbopogon. It would lay a good foundation for the phylogenetic, genetic diversity, and genomic studies of Cymbopogon plants, as well as for the discovery and utilization of important functional genes.

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.

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.

Chitinase plays a crucial role in plant stress resistance and growth development. To elucidate the effects of plant hormones and environmental stress on the expression of the mustard chitinase gene, this study investigated three plant hormones-salicylic acid (SA), 1-amino-cyclopropane-1-carboxylic acid (ACC), and methyl jasmonate (MeJA)—and the influence on the transcriptional regulation of the chitinase gene family in Brassica oleracea cv. BaiHua. Additionally, seedlings were subjected to two stress conditions: infection by Pectobacterium carotovorum subsp. Brasiliense and exposure to high temperature. The transcriptional levels of the Chinese kale chitinase gene family members were analyzed using the quantitative real-time polymerase chain reaction (qRT-PCR) method. Results demonstrated that among the 18 genes within the chitinase gene family of Chinese mustard, 16 exhibited significant induction under soft rot fungal infection, while 8 responded to high-temperature stress. Furthermore, all 18 genes showed responsiveness to plant hormone-induced expression. This study highlights the potential role of the chitinase gene in mediating responses to hormonal signals and environmental stress, thereby contributing to stress resistance and growth development in plants. The findings would provide valuable insights for future molecular breeding strategies targeting Chinese kale.

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.

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.

Improving and upgrading the efficiency of sugar factories and income of sugarcane farmers are the fundamental goals of the sugarcane industrial development. This study introduced the breeding process of the early-maturing, high-sugar, high-yield, automatic defoliation new sugarcane variety Guitang 76 (GT76) and its production efficiency in different regions, in order to provide planting technical basis for this new sugarcane variety in the coming years. Guitang 76 was selected through the “five nurseries” breeding procedure, and developed based on traits of early maturity, high sugar content and high yield, and also included characteristics of strong perennial roots, high uniformity, tolerance to drought, disease and infertility, and automatic defoliation. Finally, the Guitang 76 production performance was evaluated through the Guangxi new sugarcane variety regional test. The main process was as follows: In April 2010, 220 seedlings were obtained from the combination of CP81-1254×ROC22, planted in the hybrid nursery. In February 2011, five healthy individual plants were selected from the hybrid nursery and planted in the selection nursery. In December 2011, two strains were selected from the selection nursery and entered the identification nursery. In January 2013, one strain was selected from the identification nursery (named Guitang 10-2118), and in February 2013, it entered the preparation variety comparison nursery. After observation and screening, it was selected into the variety comparison nursery in March 2014, and later selected for the 2021—2023 of Guangxi sugarcane new variety regional trials (one year new planted sugarcane and two years perennial sugarcane trials). The results of regional trials showed that the stem diameter of Guitang 10-2118 was between 2.5–3.0 cm, which is a medium-large stem variety, the average number of effective stems was 8140 per hm² more than that of the control variety ROC22. The yield of newly planted sugarcane was 7.72% lower than that of ROC22, but the yield of perennial sugarcane in the first year was 7.28% higher than that of ROC22, and the yield of perennial sugarcane in the second year was 15.24% higher than that of ROC22, and the average yield in three years was higher (5.24%) than that of ROC22. The average sucrose content from November to March was 15.04%, which was 1.32% higher than that of ROC22. Guitang 10-2118 also showed other significant traits including tall plants, long internodes, automatic defoliation, strong perennial roots, wide adaptability, high resistance to smut and tip rot, etc. Guitang 10-2118 was renamed as Guitang 76 (GT76). This article also introduced the key points of cultivation strategies of GT76, providing technical support for its promotion, application and better cane production in coming years.

The 3^rd to 5^th instar nymphs and adults were released in tobacco fields and greenhouses to investigate the differences in dispersal capacity and dynamic patterns across developmental stages of Eocanthecona furcellata (Wolff). Under greenhouse conditions, dispersal characteristics including release timing, spatial distribution, diffusion coefficients and colonization rates were analyzed. Additionally, dispersal velocities across different developmental stages were measured under field conditions. Results demonstrated variations in dispersal capacity among developmental stages within 12-48 hours post-release, showing a gradual enhancement trend with advancing insect age. Throughout the release period, adults exhibited significantly higher dispersal coefficients than nymphs in tobacco fields, while in greenhouses, adult dispersal coefficients only surpassed nymphs significantly during 12-24 hours post-release. During dispersal, nymphs in the greenhouse primarily clustered on tobacco plants, while the majority of adults exhibited a radial dispersal tendency. At 72 hours post-release, significant differences in colonization rates emerged among developmental stages in greenhouses, with adults achieving markedly higher rates than nymphs, demonstrating a stepwise decline as instar levels decreased (adult>5^th>4^th>3^rd). Dispersal patterns stabilized with prolonged release duration. This study would provide critical evidence for scientifically evaluating the biocontrol potential of E. furcellata, offering substantial significance for enhancing natural enemy efficacy and advancing scientific pest management strategies.

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.