Albino plants lacking photosynthetic pigments are ideal materials for studying photosynthesis. In this study, albino Artocarpus heterophyllus seedlings (AAS) were found during the preliminary investigation. AAS have larger leaves, longer survival time and stable phenotypic traits, so it is a rare woody plant albino material. The expression of photosynthesis-related genes were analyzed through transcriptome sequencing technology and found that the expression of many genes in photosynthetic pigment synthesis, photosynthesis-antenna protein, photoreaction and carbon fixation reaction pathways were down-regulated in AAS leaf, also the expression of genes encoding heat shock protein 70 (HSP70), heat shock protein 90 (HSP90) and HSP70-HSP90-organizing protein 3 (HOP3), which are considered to be key regulators in the plastid-nuclear signaling pathway, were up-regulated. This study discussed the cause of AAS from the synthesis pathway of photosynthetic pigment, and also discussed the expression of photosynthesis-related genes from the aspect of plastid-nuclear signal, which can provide reference for the research of this retrograde signaling pathway.

Plant fructokinase (FRK) specifically catalyzes fructose phosphorylation into glycolysis pathway, which is a key enzyme for fructose metabolism and soluble sugar accumulation. This study elucidated the expression pattern and enzyme characteristics of red pitaya HpFRK2 gene, which would provide a theoretical basis for understanding the molecular mechanism of fruit soluble sugar accumulation and improving fruit quality. HpFRK2 was cloned from red pitaya ‘Zihonglong’, and its expression pattern was analyzed by real-time fluorescence quantitative PCR. Subcellular localization was performed by transiently expressing in tobacco mesophyll cells, and the recombinant protein was obtained by prokaryotic expression and its enzyme activity was detected. The open reading frame (ORF) was 1026 bp, encoding 341 amino acids. The relative molecular weight of HpFRK2 was 36.95 kDa, and the theoretical isoelectric point was 5.94. Phylogenetic analysis showed that HpFRK2 was closely related to cassava MeFRK2, tomato SlFRK1, apple MdFRK1 and Arabidopsis AtFRK1. HpFRK2 contained a conserved domain of the phosphofructokinase type B (pfkB) family. The expression level of HpFRK2 was the highest at 20 days of fruit development, gradually decreased with fruit development, and the expression level was the lowest at 30 days. In addition, the expression of HpFRK2 in stems was significantly lower than that in fruits. Subcellular localization results showed that HpFRK2 was mainly located in the cytoplasm. A prokaryotic expression vector was constructed and expressed in Escherichia coli, and recombinant protein was successfully induced. The results of enzyme activity characteristics showed that HpFRK2 specifically catalyzed fructose phosphorylation, fructose did not have the substrate inhibition on its enzyme activity, and the Km value for fructose phosphorylation was 1.84 mmol/L. The results showed that HpFRK2 was located in the cytoplasm, specifically catalyzed fructose phosphorylation, was mainly expressed during the veraison period (20-23 d after flowering) of red pitaya fruit, and may negatively regulate fructose accumulation in fruit.

An antimicrobial peptide (SAMP) derived from Microcitrus australasica can not only reduce the concentration of Candidatus Liberibacter asiaticus (CLas) in the infected trees and reduce the symptoms of the diseased trees, but also induce innate immunity and prevent the infection of Huanglongbing in healthy trees that are not infected with Huanglongbing. MaSAMP was analyzed by functional structure, subcellular localization and phylogeny. The results showed that the open reading frame (ORF) of MaSAMP was 201 bp in length, encoding 67 amino acids. The molecular weight of the corresponding protein was 7.59959 kDa, the theoretical isoelectric point was 5.38, and the instability index (Instability index (II)) was 33.22. The aliphatic index was 87.16%, and the grand average of hydropathicity was -0.09, indicating that the protein was a hydrophilic one. The protein contained one Dabb domain and was predominantly structured by α-helices and random coils. In terms of evolution, MaSAMP was phylogenetically close to the stress-response A/B barrel domain-containing protein CISIN_1g033887mg from Citrus sinensis and the A/B barrel domain protein HS1 from Citrus×clementina, with protein similarity of 97.01% and 91.04%, respectively. Subcellular localization results indicated that MaSAMP was localized in chloroplasts. Furthermore, through homologous recombination, a pCAMBIA1300-35S::MaSAMP-EGFP overexpression vector fused with an EGFP fluorescent tag was successfully constructed, and transgenic citrus plants were obtained using agrobacterium-mediated in planta transformation technology. This study would provide a material basis for subsequent research on the biological functions of MaSAMP.

STAY-GREEN (SGR) is a key gene that regulates chlorophyll degradation in plants and plays an important role in controlling plant senescence. To investigate the regulatory role of the SGR gene in the fruit coloration process of pepper, the homologous gene cloning method was employed to amplify the CaSGR gene from pepper fruit cDNA using PCR technology in this study. Bioinformatics analysis was conducted on its protein sequence, and a virus-induced gene silencing (VIGS) vector was constructed to preliminarily verify the gene function. The results showed that ORF of CaSGR was 792 bp, encoding 263 amino acids. Bioinformatics analysis revealed that SGR was relatively conserved among Solanaceae crops, and SGR had a closer evolutionary relationship with SGR from tomato and potato. CaSGR VIGS vector was constructed and injected into pepper leaves, successfully obtaining silenced plants. The silenced plants exhibited leaf whitening, fruit color changed, and CaSGR expression levels reduced significantly. Additionally, the chlorophyll and β-carotene content in the fruits of the silenced plants increased markedly. This study would provide a foundation for further elucidating the molecular regulatory mechanisms of CaSGR in pepper fruit coloration and offer theoretical support for breeding new pepper varieties with high carotenoid content.

Meloidogyne enterolobii is a pathogen causing significant damages to pepper production. Utilization of resistant cultivars is the most economical and environmentally friendly method to control this disease. A deeper understanding of the regulatory mechanisms of resistance to root-knot nematodes could facilitate the breeding process of disease-resistant cultivars. In previous studies, analysis of transcriptomic data of Hainan local M. enterolobii-resistant pepper germplasm CF25 before and after inoculation were carried out to explore metabolic pathways closely related to nematode resistance. In order to further explore the regulatory mechanisms of resistance, sRNA libraries of CF25 before and after inoculation with M. enterolobii were sequenced to identify a total of 133 differentially expressed miRNAs. Based on the criteria of P≤0.05 and |log₂(FC)|≥3, 33 significantly differentially expressed miRNAs were identified, including 19 known miRNAs and 14 newly discovered miRNAs. Target gene prediction for the 33 miRNAs yielded a total of 373 target genes, with miR5658-z having the highest number of predicted target genes. GO and KEGG analyses showed that the target genes were mainly enriched in pathways related to plant-pathogen interactions and signal transduction. It is speculated that miRNA-mediated signal transduction and plant defense responses might be important reasons for the resistance of CF25 to M. enterolobii. To preliminarily verify the regulatory relationships between differentially expressed miRNA and the target genes, six differentially expressed miRNA and the target genes were selected for qRT-PCR validation. The results showed that the differential expression trends of miRNA and target genes were consistent with the high-throughput sequencing results and generally conformed to the negative regulation pattern between miRNA and the target genes. The results of this study suggest that miRNA may play significant roles in the defense response to root-knot nematodes and lay the foundation for furtherly elucidating the mechanisms of miRNA-mediated nematode resistance in pepper.

Seed shattering is the main reason for the continuous self-reproduction and spread of weedy rice in rice fields. Genes SH4 and qSH1 are considered to be the main genes controlling rice seed shattering. The aim of this study was to determine the genotype of the seed shattering SNP locus at SH4 and qSH1 of weedy rice in Hainan. Using weedy rice from rice fields in Lingao and Yazhou District as research materials, this study collected weedy rice and corresponding cultivated rice seeds from 13 rice fields. 144 Weedy rice seeds with different phenotypes and 13 corresponding cultivated rice seeds were selected for germination and planting, and the seed shattering rates were measured. PCR amplification and sequence analysis were performed on the seed shattering SNP locus at SH4 and qSH1. The results showed that there were 77 wild type (G) weedy rice plants, 48 mutant type (T) weedy rice plants, and 19 heterozygous type (G/T) weedy rice plants with the locus at SH4 gene; Seed shattering SNP locus of SH4 gene in all cultivated rice samples were T. The determination of seed shattering rate found that 96 weedy rice samples with G and G/T genotype seed shattering SNP at SH4 gene had extremely high seed shattering rates, while among 48 weedy rice samples with T genotype seed shattering SNP locus at SH4 gene, 40 weedy rice samples had moderate seed shattering rates and 8 weedy rice samples had low seed shattering rates. Seed shattering SNP locus of qSH1 in all weedy rice and cultivated rice samples were wild-type seed shattering G genotype. The above results indicate that the difference in seed shattering rate between Hainan weedy rice and cultivated rice is not related to the seed shattering SNP locus at qSH1 gene, but significantly correlated with the seed shattering SNP locus at SH4 gene. The difference in seed shattering rate between weedy rice and cultivated rice with T genotype SNP locus at SH4 gene may be caused by differences in other unknown genes or locus. This study would provide a molecular basis for the seed shattering mechanism of weedy rice in Hainan.

Bok choy (Brassica campestris ssp. chinensis) is an important vegetable crop native to China and is also one of the leafy vegetables favored by people in Hainan. The high temperature and intense sunlight in Hainan’s summer greatly affect the normal growth and development of bok choy, reducing its yield and quality. At present, research on the growth of bok choy under abiotic stress is mostly focused on heat tolerance, while study on the response of bok choy to strong light stress is relatively scarce. To investigate the molecular regulatory mechanisms of bok choy in response to strong light, this study used the variety ‘Aijiao Huang’ as the research object. We compared and analyzed the physiological indicators, photosynthetic characteristics, and expression levels of response genes in the leaves of bok choy under normal light [300 μmol/(m²·s)] and strong light [1500 μmol/(m²·s)]. Under strong light, dry weight of bok choy significantly increased, and the R/S ratio gradually increased from day 0 to day 10, followed by a significant decrease on day 15. The chlorophyll content significantly decreased in the later stages. Pn, Tr, and Gs significantly increased on day 5 under strong light, and then gradually decreased, while Ci remained relatively stable. Using RNA-seq technology for transcriptome sequencing, a total of 2324 differentially expressed genes (DEGs) were identified. GO and KEGG enrichment analyses revealed 14 DEGs related to photosynthesis and photoprotection mechanisms, and 6 DEGs associated with antioxidant enzyme activity. 8 DEGs were selected for qRT-PCR validation, which were consistent with the transcriptome sequencing results, confirming the reliability of the transcriptome analysis. Strong light had a certain impact on the antioxidant enzyme activity of bok choy. During days 0-5, the activity of SOD, POD, and CAT was induced to increase, while from days 5-15, the activity of SOD and POD gradually decreased, and CAT showed an upward trend. In summary, bok choy may rapidly respond to photosynthesis-related mechanisms and regulate antioxidant enzyme activity under strong light conditions, thereby alleviating the inhibitory effects of strong light on growth and enhancing the seedlings adaptability to strong light.

The study investigated the effects of different exogenous hormones on somatic embryo maturation to improve the maturation efficiency of somatic embryos and increase the yield of normal mature embryos and embryo-derived plantlets in the rubber tree variety Yunyan 73-477. Primary somatic embryos from anthers at different developmental stages were cultured on media supplemented with various types and concentrations of exogenous hormones. The maturation rates, normal mature embryo rates, and plantlet conversion rates were comprehensively analyzed to compare maturation efficiencies and optimize hormone combinations for different developmental stages. The maturation efficiency increased with embryo developmental progression, with cotyledon embryos showing optimal results. The maturation rates exceeded 50% [range: 50.74%-74.83%, mean: (66.25±6.98)%]. Most mature embryos displayed bipolar structure and could normally germinate into complete plantlets, with normal mature embryo rates ranging from 35.0%- 59.96% [mean: (47.80±6.89)%] and plantlet conversion rates ranging from 15.62%-49.17% [mean: (26.67±8.99)%]. Torpedo-shaped embryos showed intermediate performance, while heart-shaped embryos performed the poorest, both with maturation rates below 31% [means: (30.05±12.68)% and (29.33±10.93)%, respectively]. Most mature embryos from the stages were malformed (leaf-like or callus-like) and failed to develop into complete plantlets. The normal mature embryo rates were only (15.64±7.01)% and (5.46±4.28)%, respectively, 32.16% and 42.34% lower than cotyledon embryos. Plantlet conversion rates were (7.22±3.41)% and (0.83±0.80)%, merely 0.27-fold and 0.03-fold of cotyledon embryos. Optimal exogenous hormones varied with developmental stages: heart-shaped embryos required 6-BA 0.5 mg/L+NAA 0.15 mg/L+KT 0.25 mg/L, torpedo-shaped embryos needed ABA 0.4 mg/L+GA₃ 0.5 mg/L+6-BA 2.0 mg/L+NAA 0.15 mg/L, and cotyledon embryos performed best with ABA 0.1 mg/L+GA₃ 1.0 mg/L+6-BA 1.5 mg/L+NAA 0.2 mg/L.

The axillary buds, which are embedded in the stem of Phalaenopsis and lurked at the base of leaves, can germinate and elongate to form pedicels under suitable conditions. The microscopic observation of the differentiation process is one of the important research contents to understand the flower development process and influencing factors of Phalaenopsis. In order to establish a paraffin section method for two different tissues with soft and hard connection, the stem segment with axillary bud was used as the test material. The preparation steps, such as fixed time, softening liquid concentration and softening time, dehydration, etc., which mainly affect the paraffin section effect, were optimized. The results showed that vacuuming the fixative and extending the fixative time to 48 h or more were conducive to the full penetration of the fixative, and the fixative effect was the best. Using 10%, 12% hydrofluoric acid solution to soften for 12, 15 days and vacuuming for 30 min during softening could greatly reduce the brittleness and hardness of stem tissues with high lignification degree, meet the soft and hard requirements of sections, and effectively solve the problem of tissue separation and fragmentation caused by uneven softening. Dehydration treatment was set up with 7 step by step dehydration gradients from 30% to 100% ethanol, and the gradual replacement steps of anhydrous ethanol to xylene were added, which could avoid the shrinkage and deformation of tissue materials of Phalaenopsis and ensure the integrity of tissue morphology. The optimized preparation method avoids the problems such as incomplete softening, separation of tissues from paraffin wax, crumpling and crushing of wax bands, and cavity of sections caused by conventional preparation of the stem segment of the axillary bud of Phalaenopsis girdle, etc. The overall structure of the obtained sections tends to be complete, the staining is uniform and bright, and the tissue cells in each part are obviously colored. Young bud tissue and lignified stem tissue can be clearly distinguished. In this study, a set of paraffin section preparation method was developed which could be applied to the stem segment of Phalaenopsis axillary bud, a soft and hard tissue material, and would provide a technical basis for further study on the differentiation process of latent axillary bud germination of Phalaenopsis.

Diversity, correlation, cluster analysis and principal component analysis were condunted on 16 quantitative traits and 13 qualitative traits of 124 germplasm resources of Abelmoschus esculentus to clarify the genetic diversity and phenotypic traits of A. esculentus germplasm resources, and to provide a reference basis for the identification, evaluation, and innovative utilization of A. esculentus resources. The coefficient of variation of the 16 quantitative traits ranged from 8.2% to 59.8%, with an average coefficient of variation of 18.7%. The genetic diversity index ranged from 1.51 to 2.07, with an average of 1.94. The diversity index of qualitative traits ranged from 0.08 to 1.52. The diversity of fruit color, leaf color and leaf margin morphology was relatively high, while traits such as petal color and sepal retention were highly conservative. Correlation analysis showed that there was a close synergistic relationship among the leaf morphology (such as leaf length and leaf width), plant structure (such as plant height and plant width) and fruit characteristics (such as fruit longitudinal diameter and weight) of A. esculentus, while there was an antagonistic relationship among yield-related traits (number of fruits per plant and number of seeds). Principal component analysis simplified the 16 quantitative traits into 4 principal components, with a cumulative contribution rate of 99.25%. The contribution rate of the first principal component was 96.17%, indicating that plant height, plant width, commercial fruit length, commercial fruit width, fruit weight, and seed number per fruit had the greatest impact on phenotypic diversity. Based on the cluster analysis of Euclidean distance, the germplasm resources of A. esculentus were divided into four major groups. Group Ⅰ accounted for 70.16% of the resources and was mainly characterized by early maturity (short flowering period), low flowering node, short plant height, small plant width, and a high number of fruits per plant. This group was suitable for breeding new varieties with early maturity, high yield, and dense planting. Group Ⅱ accounted for 25.81% of the resources and was characterized by larger fruits, heavier single fruit weight, and larger leaves, which could be used for breeding mid-season varieties. Group Ⅲ and Group Ⅳ were primarily characterized by late maturity, taller plant height, larger leaves, and higher biomass yield, making them suitable for breeding feed-purpose varieties. Through quantitative and qualitative trait analyses of genetic diversity in okra germplasm resources, as well as principal component analysis and cluster analysis, the genetic variation, correlations, and genetic diversity relationships among various traits were elucidated. This study identified traits associated with early maturity and high yield, laying a foundation for the conservation and efficient utilization of okra germplasm resources, as well as for breeding new early-maturing and high-yielding varieties.

The growth of fruit trees inevitably casts a certain degree of shade on the grass plants in the orchard. Therefore, the selected grass species usually need to possess a certain level of shade tolerance. This study investigated the shade tolerance of two prevalent ground cover species in southern China, Alysicarpus bupleurifolius (L.) DC. and Alysicarpus vaginalis (L.) DC.. Different shading treatments were set with full light as the control (CK). Growth and physiological indices of the two species were measured, and a comprehensive evaluation of the shade tolerance was conducted to assess the potential as ground cover species in orchards. Findings indicated that as shading intensified, both species exhibited an overall increase in the leaf width, leaf area plant height and the proportion of aboveground biomass, while the stem diameter and total biomass showed a downward trend. Compared with A. vaginalis, the leaf area of A. bupleurifolius increased faster after 21 days of shading treatment, and the total biomass decreased less after 42 days of shading treatment. After shading treatment, the PSII maximum photochemical quantum yield (Fv/Fm) of the two plants was higher than 0.80, and shading did not cause serious damage to the photosynthetic system of the two plants.The relative electrical conductivity and malondialdehyde content of the leaves of the two species generally rose with increased shading intensity, whereas the peroxidase activity (POD) activity under shading conditions displayed distinct patterns. With the increase of shading intensity, the POD activity of A. bupleurifolius increased first and then decreased, while that of A. vaginalis showed a downward trend. Principal Component Analysis (PCA) was performed to reduce the dimensionality of 14 shade tolerance indices into two principal components, which cumulatively accounted for 88.66% of the total variance. In the first principal component (PC1), the contribution rate of malondialdehyde (MDA) content was the highest. In the second principal component (PC2), the contribution rate of leaf relative conductivity was the highest. The results of comprehensive evaluation of shade tolerance by membership function method showed that A. bupleurifolius was higher than that of A. vaginalis under identical shading conditions, indicating that the shade tolerance of A. bupleurifolius was higher than that of A. vaginalis. In summary, both A. bupleurifolius and A. vaginalis exhibit noticeable shade tolerance, with A. bupleurifolius outperforming A. vaginalis, thereby affirming the potential as viable orchard ground cover species.

Crotalaria pallida is an annual diploid self-pollinating plant of the genus Crotalaria in the Fabaceae family. It was described and published by WILLIAM TOWNSEND in 1789. Geographical studies believe that the species originated in the southeastern part of the Africa continent and Madagascar. Biologically, the species have the characteristics of high seed yield, wide adaptability, and fast growth, which makes it widely spread and distributed in tropical and subtropical regions around the world. The wide distribution has attracted the attention of ethnobotany and natural science research. It is generally believed that it is an important agricultural plant resource with great development potential in feed development, soil ecological restoration, and medicinal development. However, the utilization of C. pallida has always relied on wild resources, and research on accurate evaluation of germplasm resources, mining of genetic diversity, and breeding of excellent varieties is limited. This article reviews the research progress in the global distribution, biological learning, cultivation technology, feed value evaluation, soil nutrient maintenance, and medicinal value evaluation of C. pallida, and summarizes the current problems and future research directions, aiming to provide an important reference for promoting the research on the utilization.

The effects of spraying different combinations of plant growth regulators and foliar fertilizers at the appropriate fruit-setting time on the fruit expansion and quality of seedless fruits of Tainong No.1 mango were studied to provide a scientific basis for the high-quality and high-yield cultivation techniques of seedless fruits of Tainong No.1 mango, and to offer a reference for the scientific application of fertilizers for the expansion of seedless fruits of other small-and medium-sized mangoes. From 2022 to 2024, the seedless fruits of Tainong No.1 mango were used and four foliar spraying treatment schemes were set up, the control group (CK) with foliar fertilizer, T₁ treatment with gibberellic acid + foliar fertilizer, T₂ treatment with gibberellic acid + plant growth regulator + foliar fertilizer, and T₃ treatment with compound plant growth regulator product + foliar fertilizer. The growth and development and fruit quality indicators of the seedless fruits were measured and analyzed. The results showed that when the fruits were 6-10 mm in size, spraying gibberellic acid + plant growth regulator + foliar fertilizer four times, the single-fruit weight of green fruits in T₁ and T₃ treatments was greater than 100 g, while the average single-fruit weight of green fruits in CK was 67.55 g, and the fruit-expanding effect was obvious. Among them, the average single-fruit weight of green fruits in T₃ treatment increased by 98.98% compared with CK. T₁ and T₃ treatments significantly increased the calcium content. T₁ and T₃ treatments significantly decreased the average density, weight loss rate, total acid content, and vitamin C content of green fruits. T₁ and T₃ treatments had no significant effect on the fruit shape index. T₂ treatment significantly decreased the soluble solid content, while T₁ and T₃ treatments had no significant effect on the soluble solid content. T₁ and T₃ treatments significantly increased the solid-acid ratio. Among them, T₁ treatment significantly increased the solid-acid ratio, which was 45.34% higher than CK, and T₂ treatment had no significant effect on the solid-acid ratio. T₁ and T₃ treatments significantly increased the magnesium content, while T₂ treatment had no significant effect on the magnesium content. T₁ and T₂ treatments significantly decreased the potassium content, while T₃ treatment had no significant effect on the potassium content. No residues of the used plant growth regulators were detected in the fruits. 1 mango in each treatment. Comprehensive score of the fruit quality of the fruits revealed the fruit quality of T₁ treatment was the best, followed by T₃ treatment. However, the single-fruit weight of T₁ treatment after full ripening was less than 100 g, which could not fully meet the market's requirement for single-fruit weight. The fertilizer combination of T₃ treatment is recommended for the production of seedless fruits of Tainong No.1 mango.

Sugarcane is a crucial crop for both sugar and bioenergy production, with sugar accumulation and cell wall formation being critical biological processes during its growth and development. This study employed transcriptome sequencing on the ROC22 sugarcane variety, collecting samples from leaves at the 1^st, 3^rd, and 5^th nodes, bark tissues at the 3^rd, 5^th, 7^th, 11^th, and 17^th internodes, and pith tissues at the 1^st, 3^rd, 5^th, 7^th, 11^th, and 17^th internodes. A comprehensive analysis of 42 transcriptome datasets using Weighted Gene Co-expression Network Analysis (WGCNA) revealed 34 distinct co-expression modules. Notably, the midnight blue, purple, and magenta modules demonstrated significant and specific correlations with the 1^st node leaf, 7^th internode pith, and 5^th internode bark, respectively. KEGG and GO enrichment analyses indicated that the modules participated in tissue-specific biological processes. The blue, yellow, turquoise, and black modules were primarily expressed in leaves, young pith, immature internodes, and bark, respectively. Within the blue module, key enzymes implicated in photosynthesis were identified, such as LFNR1, PSAK, PETE, PSAN, and NADP-ME4, which are essential for the initial production and accumulation of sugar in sugarcane. The yellow module featured a sucrose metabolism network centered on SUS4, including SWEET2 and an array of sugar transport-related enzymes and proteins, suggesting that the pith serves as the primary site for sugar transport and storage in sugarcane. The turquoise module contained glycoproteins and enzymes potentially involved in the synthesis and modification of the primary cell wall. Meanwhile, transcription factor NST1, which regulates secondary cell wall biosynthesis, along with other cell wall-modifying enzymes in the black module, may contribute to cell wall deposition in the cortex, providing mechanical strength and a barrier against external stresses for sugarcane. The findings would provide important references for studying the regulatory networks of sugar accumulation and cell wall formation in sugarcane.

Sugarcane (Saccharum hybrids spp.) is an important sugar crop and cash crop in Guangxi. Revealing the characteristics of sugarcane nutrient requirements is an important foundation for promoting high yield, high quality and efficient cultivation of sugarcane. In recent years, the selection and application of new sugarcane varieties in China have been rapid. A field experiment was conducted in the main sugarcane producing areas of Guangxi on red upland soil to promote the efficient cultivation of new sugarcane varieties. The dry matter accumulation, nutrient accumulation, and nutrient efficiency of GT44, GT49, GT55, GT58 and YT00-236 in both plant and ratoon crops were analyzed. The results showed that the dry matter accumulation in the 2^nd ratoon crop of the five varieties was significantly higher than that in the plant and 1^st ratoon crops. The accumulated amount of stalk dry matter and whole crop dry matter in three crops were the highest in GT58, reaching 66 946 kg/hm² and 96 785 kg/hm², respectively, which was 6.48%-19.01% and 2.57%-25.06% more than that in the other varieties, followed by YT 00-236, and the least in GT 49. The accumulation of N, P and K in the 2^nd ratoon crop was significantly higher than that in the plant and 1^st ratoon crops for all the varieties. In different crops, the accumulation of N, P and K in the five varieties was 99.81-212.18, 11.04-27.01, 150.09-400.29 kg/hm², respectively. The accumulated amount of N, P and K in the three crops was the highest in GT58, which increased by 5.16%-20.75%, 4.38%-31.85% and 6.29%-21.45%, respectively, compared with the other varieties, and that in GT49 was the lowest. The N, P, K requirement of a ton cane in different crops for the five varieties was 1.66-2.59, 0.19-0.30 and 2.76-3.76 kg, respectively, but GT44 and GT55 had more requirements while GT49 had less requirements. The economic efficiency of nitrogen, phosphorus and potassium in the three crops was higher in GT49, and the physiological efficiency of nitrogen, phosphorus and potassium was higher in YT00-236. In conclusion, the biological production of GT58 is better, and the nutrient efficiency of GT49 and YT0026 is higher.

The application of exogenous trace elements can help improve the yield and quality of certain economic crops. However, the effects of exogenous zinc on the photosynthetic physiological characteristics and volatile compounds in Pandanus amaryllifolius Roxb. (Pandan) remain unclear. Therefore, this study established a field control experiment on Pandan leaves with different zinc spray treatments, 0 kg/hm² (CK), 3.2 kg/hm² (Zn₁), 4.0 kg/hm² (Zn₂), and 4.8 kg/hm² (Zn₃). The aim was to monitor the temporal and spatial dynamics of the photosynthetic rate and volatile compounds content following zinc fertilization. The results indicated that Zn₂ treatment significantly increased the chlorophyll content, promoted the leaf growth and development, and resulted in the highest leaf count at all stages post-treatment. However, prolonged high-concentration zinc fertilization could inhibit leaf expansion and plant height. The photosynthetic physiology, photosynthetic rate, stomatal conductance, and transpiration rate increased with zinc concentration. Around 30 days post-treatment, Zn₃ treatment performed the best, followed by Zn₂ treatment. Zinc fertilization increased the content of volatile compounds. Zn₂ and Zn₃ treatments were notably effective in promoting the synthesis of several volatile compounds, such as 2-acetyl-1-pyrroline, 2-hexadecanol, and ethyl palmitate. Under Zn₂ treatment, the content of 2-acetyl-1-pyrroline and 2-hexadecanol increased by 203% and 80.89%, respectively, compared with CK. Zn1 treatment significantly increased 2-acetyl-1-pyrroline content at 20 days post-application, while Zn₃ treatment significantly promoted the synthesis of squalene, neophytadiene, and phytol. Correlation analysis showed that the main volatile compounds in Pandan interacted with agronomic traits and photosynthetic physiological indicators. The increase in photosynthetic rate and leaf count promoted the synthesis of squalene and neophytadiene, whereas elevated intercellular CO₂ concentration might inhibit the accumulation of 2-acetyl-1-pyrroline and squalene. This study demonstrates that appropriate zinc fertilization can effectively enhance photosynthesis, increase chlorophyll content, promote leaf growth, and boost the content of volatile compounds and characteristic volatile compounds in Pandan. The findings would provide a theoretical basis for optimizing high-efficiency cultivation techniques for Pandan and promoting the sustainable development of Pandan-related industries.

The response of nitrogen, phosphorus and potassium nutrient accumulation, yield and output value of flue-cured tobacco in multi-planting area of tobacco-rice to the nitrogen application and basal-topdressing ratio was studied to provide a theoretical basis for the development of fertilizer application strategies for paddy-tobacco. Cultivar Yunyan 87 was used and three nitrogen application treatments (150 kg/hm², 165 kg/hm² and 180 kg/hm²) and two basal-topdressing ratio of nitrogen treatments (3:7 and 5:5) were set up. The effects of nitrogen application and basal-topdressing ratio on the accumulation and distribution of nitrogen, phosphorus and potassium nutrients, also on yield, output value and fertilizer utilization of paddy-tobacco, and the contribution rate of nitrogen application and basal-topdressing ratio and the interaction to the accumulation of nitrogen, phosphorus and potassium were analysed using the effect value (η²_p). The results showed that nitrogen, phosphorus and potassium nutrients accumulated by flue-cured tobacco were mainly allocated to tobacco leaves, and the proportion allocated to tobacco leaves decreased with the growth of flue-cured tobacco. With the increase of nitrogen application, nitrogen accumulation and tobacco yield and output value of flue-cured tobacco increased, meanwhile reducing the proportion of base fertilizer nitrogen could significantly increase the nitrogen accumulation of the tobacco plant and yield and output value of tobacco leaf, also significantly increase the utilization rate of nitrogen fertilizer and the partial productivity and the partial production benefit of nitrogen, phosphorus and potassium fertilizers. On average, nitrogen application and basal-topdressing ratio and the interactions contributed 42.89%, 29.63% and 27.47% to nitrogen accumulation of flue-cured tobacco, and 38.62%, 24.12% and 37.25% to phosphorus accumulation, and 41.22%, 21.24% and 37.54% to potassium accumulation, and 62.13%, 6.34% and 31.53% to yield, and 47.30%, 14.74% and 37.95% to output. Throughout the reproductive period, nitrogen accumulation was relatively high in the nitrogen treatments of 180 kg/hm² and the 3:7 basal-topdressing N ratio. In the rosette stage and dome stage, the accumulation of phosphorus and potassium was relatively high in the nitrogen treatments of 180 kg/hm² and 3:7 basal-topdressing N ratio. The highest yield and output value were achieved in the nitrogen treatments of 180 kg/hm² and 3:7 basal-topdressing N ratio. Therefore, in the multi-planting area of tobacco-rice, the nitrogen application has the greatest influence on the accumulation of nitrogen, phosphorus and potassium nutrients in flue-cured tobacco, and the reduction of the proportion of base fertilizer nitrogen from 50% to 30% can increase the accumulation of nitrogen of tobacco leaf, which is conducive to the improvement of the yield and output value of tobacco leaf and the utilization rate of nitrogen fertilizer.

The three-year-old Phyllostachys prominens in the coastal sandy land of Dongshan was used to determine the contents of chlorophyll (Chl), soluble protein (SP), soluble sugar (SS), proline (Pro), and malondialdehyde (MDA) in the leaves in different seasons, and to explore the difference of physiological indexes of bamboo leaves under different seasonal environmental conditions, and analyze its adaptation in different seasonal environments in coastal sandy land, provide theoretical basis for constructing a more complete, abundant and economically valuable coastal shelter forest ecosystem. The chlorophyll a (Chla) and chlorophyll b (Chlb) had the same seasonal variation trend, and reached the highest content in summer. The total chlorophyll content in summer was 24.54%, 11.39% and 21.2% higher than that in autumn, winter and spring, respectively. The content of SP was the highest in winter and the lowest in summer. The content of SP in winter was 50.65%, 131.42% and 18.52% higher than that in spring, summer and autumn, respectively. The content of SS in summer was significantly higher than that in other seasons, which was 269.83%, 112.65% and 99.93% higher than that in spring, autumn and winter, respectively. The content of MDA decreased gradually from autumn to summer, and the difference between seasons was significant. The content of Pro was the highest in summer, which was 18.37%, 44.06% and 23.13% higher than that in spring, autumn and winter, respectively. Temperature and precipitation had significant effects on soluble sugar, soluble protein and malondialdehyde content. In the coastal area of Dongshan, during the same period of temperature and precipitation, compared with the highest and lowest periods of temperature (precipitation), the content of soluble sugar increased by 99.93%, the content of soluble protein decreased by 56.79%, and the content of malondialdehyde decreased by 52.72%. In summary, P. prominens ensures the smooth progress of photosynthesis by regulating chlorophyll content, and adapts to seasonal changes by regulating the content of osmotic substances. Photosynthesis and osmotic adjustment system are the key mechanisms for P. prominens to adapt to adversity environment.

Rubber tree is one of the “Three Trees” of Hainan, and it is cultivated in several cities and counties across the island. Rubber tree powdery mildew is a typical airborne fungal disease that occurs annually, severely affecting rubber yield and tree health. This study analyzed the potential airborne dispersal pathways of rubber tree powdery mildew spores from February 1, 2021, to March 31, 2023, with a focus on Baoting as the starting point for spore diffusion. Using the Lagrangian Hybrid Single-Particle Trajectory (HYSPLIT) model, airflow trajectories at various altitudes were simulated, and trajectory clustering analysis was performed with TrajStat software and the MeteoInfoMap platform to identify representative air mass transport paths. Results indicated that Baoting was the earliest outbreak area of rubber tree powdery mildew in Hainan, where airflows predominantly spreaded southwestward and northwestward, covering neighboring regions such as Sanya, Ledong and Wuzhishan. This suggests that spore dispersal via airflow may accelerate disease progression in the areas. Additionally, the study found that the spatiotemporal dynamics of spore spread primarily occurred from January to April each year, coinciding with the spring temperature and humidity conditions in Hainan and the phenological stages of rubber trees. The average budburst and disease onset times in Baoting preceded those in other regions, further the importance of Baoting as an early monitoring and warning site for powdery mildew in rubber trees. In conclusion, this study reveals the regional spatiotemporal transmission patterns of powdery mildew spores in Hainan island through the simulation and analysis of airborne spore dispersal from Baoting. The findings would provide scientific evidence and technical support for the formulation of targeted regional control measures, contributing to the effective management of powdery mildew and the stable development of Hainan’s rubber industry.

Xinglong coffee, a pillar of the local characteristic agriculture in Wanning, faces severe threats to its sustainable production from anthracnose. This disease can cause leaf scorching, branch ulcers, and berry brown rot, making it one of the major diseases in the industry. In this study, samples of coffee anthracnose were collected from the main coffee-growing areas in Wanning and the pathogenic fungi were isolated. The pathogenic fungi were identified through the combined analysis of multiple genes, including ITS, TUB2, CHS-1, ACT and GAPDH. Furthermore, a rapid detection system based on the loop-mediated isothermal amplification (LAMP) technique was established. 50 typical disease samples were collected, and through tissue separation and purification, a total of 24 Colletotrichum isolates were obtained. The pathogen population structure in the five planting areas of Wanning was clarified to comprise four species of Colletotrichumspp.: C. tropicale, C. karstii, C. fructicola, and the dominant species was C. siamense (accounting for 45.8%). Based on the specific region of TUB2, a specific LAMP primer set (Tub-L1) was designed and screened. The optimized reaction parameters were established as follows: isothermal amplification at 63 ℃ for 50 minutes, outer-inner primer concentration ratio of 8:1, Mg²⁺ 8 mmol/L, dNTPs 0.8 mmol/L, and without the need for betaine. Validation experiments demonstrated that the detection sensitivity of this system reached 100 pg/μL (10 times higher than conventional PCR). Furthermore, the system showed no positive reactions to seven closely related species within Colletotrichum spp. (including C. tropicale, C. fructicola, C. karstii) or seven non-target plant pathogens [including Hemileia vastatrix (coffee leaf rust), Diaporthe phaseolorum, and others]. Using the optimized LAMP detection system, the diseased leaf samples collected from the field were analyzed. C. siamense was successfully detected in all samples, and the results were completely consistent with those obtained by conventional PCR methods. In summary, the LAMP-based rapid detection system for Colletotrichum sp. established and optimized in this study demonstrates significant advantages, including simplified operation, high reaction efficiency, strong specificity, enhanced sensitivity, and visualizable results, making it highly suitable for field-based rapid detection of C. siamense. This system would provide reliable technical support for the precise identification and efficient detection of coffee anthracnose fungus, and have important practical significance and application value for the early warning, disease monitoring, and integrated control of coffee anthracnose.

Odontoglossum ringspot virus (ORSV), one of the major pathogens affecting orchids, seriously degrade the ornamental and economic value of orchids by causing leaf chlorosis, mottling, and floral deformities. To enable early-stage diagnosis, this study developed a rapid reverse transcription-recombinase polymerase amplification (RT-RPA) assay targeting ORSV. Primers and a fluorescent probe were designed based on conserved regions of the ORSV coat protein (CP) gene. Specificity, sensitivity and field applicability of the assay were systematically validated in this study. Results identified F1/R1 as the optimal primer pair, enabling amplification within 20 minutes at 41 ℃. The method exhibited high specificity, distinguishing ORSV from Cymbidium mosaic virus and Cucumber mosaic virus, and achieved a detection limit of 2.8×10^-5 ng/μL total RNA. Practical verification result of 20 Phalaenopsis field samples showed 100% concordance with TaqMan qPCR results. The RT-RPA assay would provide a rapid, sensitive, and field-deployable tool for ORSV surveillance, supporting timely disease management and sustainable orchid cultivation. Its simplicity and reliability make it particularly valuable for large-scale screening in industrial orchid production systems.

Monascus is usually used in food and medical industries. To explore the biocontrol potential of Monascus and its secondary metabolites against plant biocontrol pathogens, in this study, through the isolation and identification of the fungi from humus samples in the rain forest, a total of five strains growing well on the potato dextrose agar medium were screened, the colonies were red, with typical Monascus morphological characteristics. The strains were identified as Monascus sanguineus based on the sequencing and analysis of ITS, LSU and pksKS gene sequences, The results of antagonistic experiments showed that the five strains of Monascus had better and more obvious inhibitory effects on Fusarium oxysporum f. sp. cubense, F. oxysporum f. sp. tracheiphilium, Phytophthora capsici, Colletotrichum gloeosporioides. After fermentation of Monascus with different media, high performance liquid chromatography (HPLC) and nuclear magnetic resonance analysis were carried out. It was found that Monascus could produce abundant secondary metabolites with strong antibacterial activity on solid medium, especially on wheat bran medium. The further pot experiment proved that Monascus could effectively reduce the wilt index of cowpea, and the best biocontrol effect was obtained when the spore concentration was 10⁶ CFU/mL. In summary, Monascus isolated from tropical rain forest showed good results of better biocontrol of plant diseases, and the secondary metabolites obtained by fermentation in rice medium had strong antibacterial activity, and could effectively control cowpea blight. Monascus strains isolated from tropical rain forest have great potential in plant disease biocontrol application, which can provide more abundant strains selection for plant disease biocontrol.

Cowpea aphids, two-spotted spider mites, and bean thrips are main pests during the cowpea seedling stage, severely impacting the growth and development of cowpea plants. To evaluate the safety and control efficacy of four seed coating treatments, 10% clothianidin flowable concentrate for seed treatment FS, 30% thiamethoxan FS, 600 g/L imidacloprid flowable concentrate for seed coating FSC and 8% fipronil FSC on three common pests during the cowpea seedling stage, this study conducted indoor pot experiments with insect infestations. The experiments aimed to evaluate the impact of the four seed coatings on cowpea emergence and the effectiveness in controlling cowpea aphids, two-spotted spider mites, and bean thrips. The results indicated that the germination rate of cowpea treated with 10% clothianidin FS, 30% thiamethoxan FS, 600 g/L imidacloprid FSC, and 8% fipronil FSC was 95.83%, 91.67%, 95.83% and 95.83%, respectively. The rate was slightly lower than that of the control (100%), but did not significantly affect crop growth. The findings revealed that 30% thiamethoxan FS exhibited the highest control efficacy against both cowpea aphids and bean thrips. Specifically, the control efficacy against cowpea aphids at 3, 7 and 14 days post-infestation was 65.04%, 81.10% and 72.35%, respectively. For bean thrips, the control efficacy at the same time points was 15.41%, 58.61% and 54.89%, respectively. As the infestation period progressed, the effectiveness of the seed coating treatments in controlling cowpea aphids and bean thrips gradually decreased. None of the four seed coating treatments demonstrated significant control efficacy against two-spotted spider mites. This research provides technical support for pest management during the seedling stage of cowpea production.

Evapotranspiration as a key component of the energy balance and hydrological cycle, not only plays an important supporting role in ecosystem stability and water resource management, but is also a crucial indicator for evaluating agricultural water use efficiency. Obtaining high spatiotemporal resolution data can reveal the dynamics of evapotranspiration, which is of great significance for analyzing ecological and hydrological processes. The region studied is rubber plantations in Danzhou city, Hainan province. Based on daily meteorological data from flux tower observations and ten corresponding scenes of Landsat 8 satellite imagery for the same period, the daily evapotranspiration of the rubber plantations in 2022 was estimated using the surface energy balance system (SEBS) model, and the results were validated for accuracy using the eddy covariance method. The results showed that the SEBS estimated daily evapotranspiration values from rubber plantations had a good correlation with the eddy covariance measured values (R²=0.88, RMSE=0.55, RE=18.95%). The daily evapotranspiration exhibited significant seasonal variation, showing that the wet season was significantly higher than the dry season. The maximum daily evapotranspiration occurred on July 31, reaching 4.40 mm, while the minimum daily evapotranspiration occured on January 28 and March 9, both at 1.38 mm. The accuracy of evapotranspiration derived from Landsat 8 imagery was influenced by factors such as vegetation cover and spatial heterogeneity. Therefore, the accuracy of the evapotranspiration varied with distance from the flux tower. Overall, the SEBS model showed the highest accuracy for rubber plantations within 1.5 km of the flux tower (RMSE=0.53, RE=18.08%), while it had the lowest accuracy for areas situated 1.0 km from the tower (RMSE=0.65, RE=22.26%). In conclusion, this study would provide a reference for improving the spatiotemporal resolution of evapotranspiration datasets, reveal the seasonal variability and spatial patterns of evapotranspiration in rubber plantations, and contribute to the development of effective water resource management and regulation policies in rubber plantation ecosystems.