Cowpea Fusarium wilt caused by Fusarium oxysporum f.sp. tracheiphilum occurs in almost all cowpea growing areas, and the yield loss can be as high as 70% in major domestic producing areas such as Hainan. Currently, chemical control measures are the primary management strategy in China. The use of microbial biocontrol agents can reduce the application of agrochemicals and mitigate the risks of pesticide residues, and has been widely adopted for the management of soil-borne diseases. However, there is limited research on the use of multi-functional microbial consortia for the biocontrol of Fusarium wilt in cowpea. In this study, we screened highly efficient phosphate-solubilizing bacteria (PSB) using the molybdenum-antimony colorimetric method, and evaluated the synergistic effects of the selected PSB strain and the antagonistic Bacillus velezensis strain on cowpea growth and Fusarium wilt control. From 10 phosphate-solubilizing bacterial isolates, we identified B. cereus LMSY3PSB-2-2 (abbreviated as P) as a highly efficient PSB strain. The optimal ratio of the PSB strain P to the biocontrol strain B. velezensis X5 was determined to be 2∶1. Compared to the individual application of the PSB strain P or the biocontrol strain X5, the composite inoculum at this ratio significantly enhanced cowpea seed germination, plant growth, and root vigor. Under pot experiments, the composite inoculum achieved a 96% disease control effect against Fusarium wilt and increased the available soil phosphorus content by 19%. The results would provide a theoretical guide for utilizing the PSB strain P and the antagonistic strain X5 in a microbial consortium to promote cowpea growth and control Fusarium wilt, laying a foundation for the development of multi-functional composite microbial products to support sustainable agriculture.

Natural rubber (NR) is an important industrial material and strategic resource. Its composition, structure, and properties are influenced by factors such as the rubber tree cultivar and processing methods, leading to significant variations in quality stability. By studying the changes in particle size and molecular weight of natural rubber prepared through different centrifugation cycles, this research explored the effects on rubber composition and performance, which is crucial for obtaining high-quality rubber. In this study, two rubber cultivars, Reyan 73397 and PR107, were selected to investigate the impact of different centrifugation cycles on the particle size of latex, molecular weight, physicochemical properties of raw rubber, and vulcanized rubber properties. After centrifugation, the particle size of the latex from both cultivars increased with the number of centrifugation cycles, and the particle size distribution became more concentrated, with Reyan 73397 having a larger particle size than PR107. The molecular weight decreased, and the molecular weight distribution narrowed as the centrifugation cycles increased. With more centrifugation cycles, the ash content, gel content, nitrogen content, and Mooney viscosity of both cultivars decreased, the vulcanization time extended, but the resistance to storage hardening increased. However, the tensile strength and tear strength were reduced. The aging resistance of the vulcanized rubber from both cultivars decreased with the increase of centrifugation cycles. Furthermore, centrifugal treatment increased the glass transition temperature (T_g) of the rubber, enhanced its resistance to wet sliding, and increased the rolling resistance and heat build-up of the rubber.

The study was aimed to study the effects of exogenous ATP and rotenone treatment on chilling injury and sugar metabolism in cold-stored guava fruits. Post-harvest ‘Hongxiang’ guava fruits were treated with distilled water, 0.8 mmol/L ATP, and 0.2 mmol/L rotenone, respectively, and stored at (4±1)℃. During storage, the chilling injury index, commercial rate, sugar content, and sugar metabolism-related enzyme activity of the guava fruits were regularly determined. Compared with the control fruit, ATP treatment reduced chilling injury, increased the activities of sucrose monophosphate synthase (SPS), acid invertase (AI), and sucrose synthase synthesis direction (SSs) during the late stage of storage, decreased the activities of neutral invertase (NI) and sucrose synthase decomposition direction (SSc) during late-storage, inhibited the increase in fructose and glucose content during mid-storage, maintained the content of sucrose and total soluble sugar at a high level, and improved the cold resistance and commercial rate of the fruit. Rotenone treatment exacerbated chilling injury by simultaneously inhibiting the increase of SSS activity and SPS activity during the middle stage of storage, the decrease of AI activity, NI activity, and SSc activity during the middle and late stages of storage, accelerating the decomposition of sucrose, increased the content of fructose, reduced the total soluble sugar and reducing sugar, and resulted in a low commercial rate of the fruit. ATP treatment could enhance cold resistance in guava fruits, and the mechanism may be related to changes in sucrose and soluble total sugar content. However, rotenone treatment induced an imbalance in sugar metabolism and exacerbated chilling injury.

Sodium alginate (SA) edible composite film incorporated with different amounts of galangal essential oil (EO)/curcumin (Cur) was prepared by solvent casting method and applied to fresh-cut pineapple in this study. The results showed that 0.3% EO could improve the thickness and thermal stability of the composite film, and reduce the water vapor penetration rate. SA-0.3%EO and SA-0.3% EO-Cur film groups had significant fresh-keeping effect on fresh-cut pineapple, while the control group showed obvious browning after three days of storage at 4 ℃. The fresh-cut pineapple in SA-0.3% EO-Cur group maintained the best appearance, followed by SA-0.3%EO group. When the storage time was extended to eight days, the weight loss of fresh-cut pineapple in the SA-0.3%EO coating group was the lowest (2.12±0.08)%, the total number of colonies (lgCFU/g) was 3.48±0.00, the number of molds and yeast (lgCFU/g) was 3.89±0.19 were the lowest. However, the appearance color of the SA-0.3% EO-Cur coated group was the best, and the antibacterial effect was second only to that of the SA-0.3%EO coated group, which was obviously better than the control group. However, when the EO content increased to 0.5%, the appearance of fresh-cut pineapple also showed browning and other quality deterioration, indicating that the concentration of essential oil would affect its preservation effect and have a negative impact on the quality of fruit. In conclusion, this study would provide a new idea for the development of a new edible film system, and provide data support and theoretical support for extending the shelf life of fresh-cut pineapple.

This study investigated the impact of different netting methods on the cowpea (Vigna unguiculata) industry. Specifically, it compared the degradation characteristics of three pesticides-matrine, spinosad, and difenoconazole-under two netting conditions (fully enclosed and semi-enclosed), the accumulation changes of pectin, cellulose, total phenols, and flavonoids, and analyzed the economic benefits of cowpea cultivation under the netting methods. The results indicated that under semi-enclosed netting conditions, the half-life of the pesticides was 1.13 days for matrine, 0.42 days for spinosad, and 1.96 days for difenoconazole. In contrast, under fully enclosed netting conditions, the half-life of the pesticides was 1.53 days, 0.83 days, and 2.51 days, respectively. Compared to fully enclosed netting, the degradation rate of the pesticides was significantly faster under semi-enclosed netting conditions. Regarding the accumulation of key substances, there was no significant difference in the contents of pectin [(15.88±2.025)mg/g] and cellulose [(1.75±0.128)mg/g] between semi-enclosed and fully enclosed conditions. However, total phenol content under semi-enclosed netting [(0.42±0.125)mg/g was 40.00% lower than that under fully enclosed netting [(0.70±0.091)mg/g], and flavonoid content [(6.08±2.509)mg/g] was 55.91% lower under semi-enclosed netting than under fully enclosed netting [(13.79±0.876)mg/g]. Economic analysis showed that considering field management, pest control investment, and market conditions, cowpea cultivation under fully enclosed netting yielded higher input and output compared to semi-enclosed netting. When the purchase price of cowpea reaches 5.11 yuan/kg (for fully enclosed netting) and 3.85 yuan/kg (for semi-enclosed netting), the profit and loss break even. This study would provide both theoretical and practical guidance for selecting appropriate netting methods for cowpea cultivation.

The residue of nitrogen fertilizer in soil is an important destination after nitrogen fertilizer application. Under tropical acidic soil conditions, it is hypothesized that the lack of carbon may further limit soil retention of nitrogen fertilizer in rubber plantation. A field micro-experiment utilizing ¹⁵N isotope tracer technology was conducted to investigate the soil nitrogen residual characteristics in rubber plantations with different nitrogen application levels (0 kg/hm², N₀; 100 kg/hm², N₁₀₀; 200 kg/hm², N₂₀₀; 400 kg/hm², N₄₀₀) under the addition of exogenous carbon (100 kg/hm²). The results showed that the soil residual rate of nitrogen fertilizer was 8.8%-17.6% in the first year and 6.6%-16.5% two years later after adding carbon. Notably, the residual rate of nitrogen fertilizer showing a downward trend was observed with the increasing of nitrogen application; compared with the treatment without nitrogen fertilizer, the lower nitrogen application level (100 kg/hm²) under carbon addition had a significant effect on enhancing both soil total nitrogen and organic carbon content. The 2-year field trial revealed that the residual rate under different nitrogen application with carbon addition was higher than that without such addition. Variance analysis showed that exogenous carbon addition had a significant positive effect on the residual rate of nitrogen fertilizer; and carbon addition could effectively enhance the soil retention of nitrogen fertilizer. In conclusion, the deficiency of soil carbon emerged as a critical factor contributing to the low nitrogen residue rates in rubber plantations; therefore, it is imperative to combine chemical fertilizers with organic fertilizers during the fertilization process in rubber plantations, while the nitrogen application rate remains moderate.

Rubber tree latex metabolic processes are regulated by a variety of mechanisms, among which ubiquitination modification is the most significant. The phloem protein PP2 belongs to the F-box protein family and is specifically highly expressed in latex, which may be involved in the regulation of latex regeneration. In this study, bioinformatics and expression pattern analysis were conducted on 17 F-box members of the HbPP2 gene identified in the genome of Hevea brasiliensis. The results revealed that the majority of proteins encoded by the rubber tree PP2 genes were unstable hydrophilic proteins with molecular weights ranging from 9.402 to 61.206 kDa. Phylogenetic analysis showed that the 17 HbPP2 genes in the H. brasiliensis could be divided into three subgroups (Subgroup Ⅰ, Subgroup Ⅱ, Subgroup Ⅲ), in which HbPP2 members were completely absent in subgroup I. Analysis of cis-acting elements revealed that the rubber tree PP2 gene family contained diverse functional elements involved in growth and development regulation, hormone response, and light response. Subcellular localization analysis indicated that PP2 proteins were primarily localized in chloroplasts or cytoplasm. Tissue expression analysis showed that, except for some members with tissue-specific expression, most members of the rubber tree HbPP2 family were expressed in various tissues. In latex, the expression levels of six genes, HbPP2-B1, HbPP2-B1.1, HbPP2-B10.1, HbPP2-A13.2, HbPP2-B13 and HbPP2-A15.1, were relatively high, but tapping treatment significantly upregulated the expression of HbPP2-A13.2 and HbPP2-B13. This study would provide preliminary insights into the physicochemical and expression characteristics of the HbPP2 family members in the H. brasiliensis, laying a foundation for further research on the functions of this genes family in rubber trees latex synthesis and metabolism.

Mango (Mangifera indica L.), as a typical climacteric fruit, undergoes ripening and senescence processes closely related to ethylene. Ethylene-responsive factors (ERF) play crucial roles in plant growth, fruit ripening and ethylene signaling transduction. Mango variety Guifei was used, MiERF20, 492 bp long and encoding 163 amino acids, was cloned and analyzed. Bioinformatics analysis revealed that MiERF20 was an unstable, hydrophilic protein without signal peptides or transmembrane regions, containing 25 phosphorylation sites and one AP2 conserved domain. The secondary structure was dominated by 40.49% irregular coils, 33.13% α-helices, 16.56% extensions and 9.82% β-rotations. Its secondary structure comprised irregular coils, α-helices, extended chains, and β-turns, consistent with AP2 domain features. MiERF20 showed 83.89% homology with ERF20 of Lacertidae pistachio. Subcellular localization indicated that MiERF20 was located in the nucleus and possessed transcriptional activation activity. Prokaryotic expression assays demonstrated that the protein could be inducibly expressed in a prokaryotic system. Real-time fluorescence quantification showed that MiERF20 was ethylene-inducible, suggesting its role in ethylene-regulated fruit ripening. This study would provide a foundation for further analysis of the functions and regulatory mechanisms of ERF transcription factors during postharvest fruit ripening.

Gene TFL1 belongs to the phosphatidylethanolamine binding protein (PEBP) family and is closely related to plant flowering regulation. To explore the functions of TFL1 gene in Dendrobium hybrid, based on the transcriptome data of floral in Dendrobium hybrid, a TFL1 gene was cloned and named DenTFL1. And the bioinformatic analysis protein structure and subcellular localization prediction, expression patterns analysis were done to explored the functional of DenTFL1. The results showed that the full length of DenTFL1 cDNA sequence was 522 bp, encoding 173 amino acids. Bioinformatics analysis showed that the molecular formula of DenTFL1 was C₈₇₀H₁₃₅₄N₂₄₆O₂₄₉S₆, the theoretical relative molecular mass of the protein was 19.43 kDa, and the theoretical isoelectric point was 7.82, and the protein was hydrophilic and structurally stable. Subcellular prediction showed that it was located in the cytoplasm, without signal peptide and transmembrane domain. The secondary structure was dominated by 61.85% of random curl, also contained 23.70% of the extended chain, 14.45% of α-helix. The three-dimensional structural model was basically consistent with the secondary structure. The conserved domain analysis showed that DenTFL1 had a conserved PEBP domain and amino acid sequence alignment and phylogenetic tree analysis showed that DenTFL1 was closely related to D. nobile and D. thyrsiflorum. The constructed protein network showed that DenTFL1 mainly interacted with AT5G63440, LFY, SOC1, AGL24, AGL8. Expression analysis showed that DenTFL1 was expressed in all tissues of different development stages of Dendrobium hybrid, and had the highest expression level in the stems of young and mature plantlet and the flower stalks, and had a lower expression level in the roots of young plantlet and the leaves and roots of medium plantlets. Moreover, it had a high expression in different development stage of inflorescence except 3.0 cm long inflorescence. It also showed high expression in 7.0 mm and 9.0 mm width floral bud and the tissues of fully open flower, but expressed lower in the tissues of early development stages of floral bud. The research could provide a reference for the flowering regulation of Dendrobium hybrid, and add relevant information for the study of TFL1.

Heat shock transcription factor (HSF) is an important regulatory factor that plays a crucial role in plant response to hot ambient temperature (HAT). High temperature stress has a serious negative impact on the flowering of passion fruit, therefore, studying the regulation of heat tolerance by HSF in passion fruit is of great significance. In this study, we identified 26 HSF genes on the genome of passion fruit using bioinformatics technology, named PeHSF1-PeHSF26. The genes could encode proteins of 100-1589 amino acids, with molecular weight 11 544.9-177 157.8 g/mol, and a theoretical isoelectric point of 4.25-10.80. The 26 genes were distributed on chromosomes 1, 4, 5, 6, 7, 8 and 9, and were divided into 10 subpopulations. The analysis of the whole genome replication event showed that ZX01G0033270, ZX01G0052790 and ZX01G0052980 were located within the genome duplications. The genes contained 1-12 introns and 2-13 exons, all contained HSF-DNA binding domains. RNA-seq analysis of Huangguo original species and Jinlingziguo HSF genes to HAT revealed that there were significant differences in the expression levels of genes, including ZX01G0002530, ZX01G0052790 and ZX01G0121040 in flower buds. The expression levels of candidate HSF genes were validated by RT-qPCR. Based on comprehensive analysis, it is supposed that the most ideal candidate HSF gene for passion flower response to high temperature stress was ZX01G0121040. The results would contribute to understand the function of HSF in response to high temperature stress during the flowering of passion fruit, and provide important genetic resources and theoretical basis for genetic improvement of passion fruit.