The maize leaf area index (LAI) is a key parameter for reflecting growth and yield of maize, and the pollination stage being crucial for determining ear kernel number and yield. This study aimed to identify an effective inversion method to accurately estimate the LAI of Nanfan maize at pollination stage. Nanfan maize at pollination stage was used as the study subject. Canopy reflectance data were acquired using a ULTRIS X20 PLUS hyperspectral imager mounted on a Jingwei M300RTK quadrotor UAV platform. Based on correlation analysis, 28 LAI-sensitive vegetation indices were selected. Two traditional empirical models, univariate linear regression (ULR) and multiple stepwise regression (MSR), and four machine learning models, partial least squares regression (PLSR), random forest regression (RFR), support vector regression (SVR) and back propagation neural network (BPNN) were employed to construct LAI inversion models. The prediction accuracy of different vegetation indices and regression algorithms was compared, and the optimal inversion model was selected for accurately predicting the LAI status of Nanfan maize at pollination stage. Most vegetation indices exhibited highly significant correlations with LAI (P<0.01). Compared to univariate regression, multivariate regression models provided higher prediction accuracy. Among them, RFR, MSR and PLSR models achieved the highest R² values, with coefficients of determination (R²) of 0.96, 0.85 and 0.80 and corresponding root mean square errors (RMSE) of 0.18, 0.35 and 0.41, respectively. By analyzing the correlation and sensitivity between hyperspectral data and maize LAI, and employing vegetation indices calculated based on hyperspectral information combined with regression algorithms, this study successfully developed a reliable LAI inversion model, and established a spatial distribution of Nanfan maize LAI at pollination stage based on the RFR model with the best inversion effect. The model would provide both theoretical support and technical guidance for LAI estimation and field monitoring of Nanfan maize growth and development.

The AT-hook Motif Nuclear Localized (AHL) protein family is known for its pivotal roles in plant growth regulation, developmental patterning, and stress signal transduction. Although the gene family has been studied in various plant species, the genomic characteristics, evolutionary mechanism, and expression profiles of the AHL family in cassava (Manihot esculenta) remain unexplored. In this study, we comprehensively investigated the evolutionary features and biological response of the MeAHL gene family through genome-wide identification, phylogenetic analysis, structural characterization, and large-scale transcriptomes based on the cassava SC205 reference genome. We identified 41 putative members through genome-wide identification. Physicochemical property analysis showed that all 41 MeAHLs were hydrophilic proteins, and 40 of them were unstable proteins, with the number of amino acids generally ranging from 188 to 446 aa. Phylogenetic analysis indicated that the MeAHL family members could be divided into two clades, Clade A and Clade B. Two MeAHL gene clusters were located in the distal telomeric regions of chromosomes Chr01 and Chr02, respectively. Replication type analysis revealed that the evolution of MeAHLs was mainly driven by whole-genome duplication (WGD) and dispersed duplication (DSD), with the Ka/Ks values <1. Evolutionary mechanism analysis indicated that whole-genome duplication (WGD) primarily drove the MeAHL gene family expansion. Gene structure analysis showed that MeAHL genes were mainly composed of 1‒10 exons. Analysis of conserved domains and motifs showed that all MeAHLs had the PPC/DUF296 domain and AT-hook motif. Members of Clade A generally contained one Type-I AT-hook motif. Among members of Clade B, except for SC20508G13380 and SC20509G13950, which contained one Type-II AT-hook motif, most members contained two AT-hooks (Type-I and Type-II). Cis-acting element analysis via PlantCARE showed that the cis-acting elements related to light response were the most abundant in MeAHLs, such as Box 4, G-box, and they also contained elements responsive to hormones, biotic stresses, and abiotic stresses, such as ABRE, MBS, W-box, and TC-rich repeats. Tissue-specific expression profiling revealed distinct expression patterns between two clades of MeAHL across 11 different tissues. Stress transcriptome analysis demonstrated significant responses of specific MeAHLs to drought (ABA/PEG treatments), cassava bacterial blight (Xanthomonas axonopodis pv. manihotis), and mite infestation, showing clade-specific regulatory patterns. Protein-protein interaction (PPI) network prediction suggested some MeAHLs formed functional modules with bHLH, NAC, ARF, and NB-LRR proteins involved in plant development and stress responses. This study would provide the systematic characterization of AHL family evolution and functional diversification in cassava, offering theoretical foundations for molecular breeding applications.

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.

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.

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.

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.

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.

During the biosynthesis process of lignin in plants, cinnamyl alcohol dehydrogenase (CAD) plays a crucial role, catalyzing the final step reaction in the entire metabolic pathway. To explore the potential functions of the CAD gene family in tea plants, CAD gene family members were identified in the genome of Huangyan tea plants and a series of bioinformatics analyses were conducted. Based on transcriptome data, the gene expression of the members in different organs of tea plants and after damage by the Empoasca vitis were studied. A total of 36 members of HD-CsCADs were identified, which were unevenly distributed on 9 chromosomes and encoded amino acid lengths ranging from 300 aa to 621 aa and protein molecular weights ranging from 321.40 kDa to 666.49 kDa. HD-CsCADs had 0 to 3 introns and the promoters containing 79 types of cis-acting elements, among which the number of elements related to stress response was the highest. Combined with the phylogenetic tree, HD-CsCADs could be divided into 4 subfamilies. There were significant differences in the expression levels of HD-CsCADs in different organs of tea plants. HD-CsCAD-15 was highly homologous to CAD genes involved in lignin biosynthesis in other plants and was highly expressed in stem tissues. In addition, the expression of the genes after damage by E. vitis on tea seedlings was analyzed. The expression of HD-CsCAD-11 and HD-CsCAD-15 was relatively obvious and could be used as important CAD genes related to lignin metabolism and tea plant defense against pests. The results would provide theoretical basis for the defense mechanism of tea plants against the small green leaf hopper and the utilization of CAD gene functions.

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.

This study was aimed to identify high-quality and stress-resistant germplasm resources of subtropical tea for the purpose of supporting new variety breeding and the development of characteristic tea products. Leaves from 50 tea accessions cultivated at Tea Teaching and Research Base of Guangxi Vocational and Technical College in Nanning were selected as the samples. 17 leaf anatomical and structural traits were examined to assess the genetic diversity. Based on stress resistance, processing suitability, productivity potential of the traits were evaluated. Principal component analysis combined with hierarchical cluster analysis was employed for the comprehensive evaluation. There existed substantial genetic variation among the accessions, and the coefficient of variation ranged from 11.00% to 39.10%. The accessions demonstrated robust stress resistance with average membership function value for drought resistance and pest resistance 0.67 and 0.61, respectively, along with average cold resistance score 6.28. The average productivity index of 3329.20 suggested a relatively high productivity potential. Based on the leaf anatomical and structural indicators, the accessions were clustered into three distinct groups. The upper cuticle thickness, lower cuticle thickness, upper epidermis thickness, lower epidermis thickness, palisade tissue thickness, palisade tissue layer number, spongy tissue layer thickness, leaf thickness, and calcium oxalate crystal indexes of the Group 2 appeared to be significantly or highly significantly different than those of Group 1 and Group 3. Based on the top five principal component values and the corresponding eigenvalues of the accessions, a linear equation was established to calculate the comprehensive score of the principal components. The top 10 accessions exhibited superior overall characteristics, demonstrating strong potential for breeding elite tea cultivars. These findings would provide valuable references for identification and utilization of the superior local tea germplasm resources in Guangxi.