The PYR/PYL/RCAR (PYL) gene family (Pyrabactin Resistance 1/PYR1-Like/Regulatory Component of ABA Receptor), as core receptors of abscisic acid (ABA), play a pivotal regulatory role in the signaling pathways of plant responses to abiotic stresses such as drought. Saccharum spontaneum L. (wild sugarcane), an important wild relative for sugarcane stress-resistant breeding, harbors abundant drought-tolerant genetic resources. However, systematic identification and functional analysis of its PYL gene family remain unreported to date. Based on the S. spontaneum genome data (Saccharum spontaneum Np-X2021), the study identified members of the SsPYL gene family using bioinformatics approaches, and systematically analyzed the physicochemical properties, chromosomal localization, phylogenetic relationships, gene structures, conserved motifs, and cis-acting elements in promoters. Additionally, quantitative real-time PCR (qRT-PCR) was employed to investigate the expression patterns of core members under drought stress. The results showed that 32 SsPYL genes, designated as SsPYL1 to SsPYL32, were identified in the S. spontaneum genome. The encoded proteins ranged in length from 149 to 385 amino acids, with most being acidic and hydrophilic proteins primarily localized in the cytoplasm. The secondary structure was dominated by α-helices and random coils. Furthermore, SsPYLs exhibited uneven distribution across chromosomes, and segmental duplication was the dominant mechanism driving family expansion. A total of 54 pairs of syntenic genes were identified between SsPYLs and rice OsPYL genes, reflecting the evolutionary conservation of this family among monocotyledonous plants. Phylogenetic analysis clustered the 32 SsPYLs into three subfamilies, with members of the same subfamily sharing similar conserved motif compositions and gene structures. All SsPYL proteins contained the signature PYR_PYL_RCAR_like domain. The promoter regions of SsPYL genes were enriched in hormone-responsive and abiotic stress-related cis-acting elements, such as ABRE (ABA-responsive element), ARE (anaerobic responsive element), and LTR (low-temperature responsive element). Under drought stress, the expression levels of eight SsPYL genes (SsPYL1, SsPYL3, SsPYL4, SsPYL6, SsPYL8, SsPYL14, SsPYL19 and SsPYL24) were extremely significantly upregulated (P<0.01), among which SsPYL8, SsPYL14 and SsPYL19 showed more than 5-fold upregulation. The genes are thus speculated to be key candidate genes regulating drought tolerance in S. spontaneum. The study represents the first systematic characterization of the molecular features and drought-responsive patterns of the SsPYL gene family in S. spontaneum. It would provide a theoretical basis for further exploring the functional mechanisms in ABA-mediated drought stress signaling pathways and offer important gene targets for the genetic improvement of drought tolerance in sugarcane.
The widely targeted metabolisms of fruit pericarp was determined, the differential metabolites were screened and the metabolic pathway was analyzed to understand the metabolomics difference of fruit pericarp at its different growth and development stages in wax apple (Syzygium samarangense). The samples were picked at 15 d (S1), 30 d (S2), 45 d (S3) and 60 d (S4) after flower respectively. A total of 946 metabolites were detected from wax apple fruit pericarp, including 177 amino acids and their derivatives, 140 flavonoids, 96 sugars and their derivatives, 96 organic acids and their derivatives, 89 lipids, 65 nucleotides and their derivatives, and 283 other metabolites. There were 65, 88, 59, 88, 112, and 103 differential metabolites in S1 vs S2, S2 vs S3, S3 vs S4, S1 vs S3, S1 vs S4, and S2 vs S4 respectively. There were only 6 common differential metabolites in six groups, of which 5 metabolites belonged to amino acids and derivatives and 1 belonged to flavonoid. The differential metabolites of fruit pericarp at different growth and development stages mainly included amino acids and their derivatives, flavonoids, sugars and their derivatives, lipids. The number of differential metabolites of flavonoids, sugars and their derivatives decreased first and then increased, while the number of lipid metabolites increased first and then decreased with the growth and development of fruit. Most flavonoid metabolites were down-regulated, while sugars and their derivatives were up-regulated. There were more lipid differential metabolites in S2 vs S3, and only 1 in S3 vs S4. The most significant enrichment pathway of differential metabolites of wax apple fruit pericarp were biosynthesis of starch and sucrose, phenylalanine, D-amino acid, galactose, terpenoids and steroids. This study would provide theoretical support and data references for the regulation of fruit quality and harvest period of wax apple.
Granule-bound starch synthase I (MeGBSSI) is the key enzyme for amylose synthesis in cassava, primarily responsible for catalyzing the formation of amylose through α-1,4-glucosidic linkages on the surface of starch granules. However, how MeGBSSI cooperates with other starch-synthetic enzymes to orchestrate starch biosynthesis remains unclear. In the previous stage of this research group, through yeast two-hybrid technology, it was hypothesized that the soluble starch synthase MeSSV was a potential binding protein of MeGBSSI. In this study, the MeGBSSI and MeSSV genes were cloned using the main cultivated variety of cassava, Huanshan 8 (SC8), as the material. Yeast two-hybrid vectors pGBKT7-MeGBSSI and pGADT7-MeSSV were constructed. Through yeast two-hybrid point-to-point experiments, the interaction relationship between MeGBSSI and MeSSV was preliminarily verified. The luciferase complementation (LCA) and double-molecule fluorescence complementation (BiFC) techniques were used to further clarify the direct protein interaction between the two. The results showed that the protein sequences encoded by the MeGBSSI and MeSSV genes, compared with the sequenced variety AM560, respectively, had 4 and 2 amino acid substitutions; the MeGBSSI protein was non-toxic to yeast cells and had no self-activation activity; this protein interacted with the soluble starch synthase MeSSV in yeast; the LCA experiment showed that the chemical signals significantly enhanced after co-expression of MeGBSSI and MeSSV; the BiFC experiment further proved that the two could form a complex in plant cells, and the interaction signal was located in the chloroplast. The findings would provide new insight into the synergistic regulation among cassava starch-synthetic enzymes.
Dwarfism is a key trait for Litchi chinensis breeding and cultivation. Focusing on the candidate gene LcGAMYB23 implicated in dwarfism by prior quantitative trait locus (QTL) mapping, we evaluated the MYB transcription factor family background and its molecular application potential. A genome-wide bioinformatic survey identified 151 members of the LcMYB gene family. Conserved motif and domain analyses showed that all family members harbored the canonical Myb_DNA-binding domain, indicating high sequence conservation in litchi. We further cloned and sequenced LcGAMYB23 from three standard (non-dwarf) cultivars (9918, Feizixiao, FZX; Sanyuehong, SYH) and three dwarf cultivars (Nuomici, NMC; Yamulong, YML; Ziniangxi, ZNX), and detected consistent sequence differences between the two groups. Based on the divergent single-nucleotide polymorphism (SNP) sites, we developed molecular markers and validated them across 70 cultivars. The markers effectively discriminated standard versus dwarf types at the cDNA level, with concordant results at the genomic DNA level. The findings would provide practical tools for molecular typing and marker-assisted selection of dwarfism in litchi and lay the groundwork for functional elucidation of LcGAMYB23.
Tomato ripening involves the coordinated regulation of key agronomic traits such as color transformation, texture softening, and flavor compound accumulation. Elucidating its molecular mechanisms is not only a central goal in postharvest biology but also crucial for improving fruit quality and achieving precise control of storage duration. In this study, the functions of SlBEL1, SlBEL2 and SlBEL11, members of the BEL family of transcription factors in tomato, were systematically investigated through multi-dimensional experiments. Phylogenetic and amino acid sequence alignment analyses revealed that SlBEL1, SlBEL2 and SlBEL11 possessed highly conserved protein domains, suggesting potential functional similarities. Spatiotemporal expression profiling showed that the genes were synchronously highly expressed during critical stages of fruit ripening, from the breaker to the full ripening stage. Using CRISPR-Cas9 technology, single-gene and triple-gene editing lines of SlBEL1, SlBEL2 and SlBEL11 were generated. The single-gene editing lines CR-SlBEL1, CR-SlBEL2 and CR-SlBEL11 all exhibited a delayed fruit ripening phenotype, while the triple editing line resulted in impaired reproductive development, failing to proceed to flowering and fruit setting. Furthermore, reverse transcription quantitative real-time PCR (qRT-PCR) analysis revealed that SlBEL1/2/11 modulated the expression of multiple ripening-related genes in tomato. Collectively, the results demonstrate that SlBEL1/2/11 functioned redundantly to coordinately control the fruit ripening process. This study identified novel targets for the genetic improvement of tomato fruit ripening.
Germplasm resources are the key material support for the breeding of new mango varieties and the sustainable development of the industry, and the efficient conservation and utilization are of great significance for mango research. In the study, 431 mango germplasm accessions were used. Combining different sampling strategies and genetic distances, the optimal sampling strategy combination for constructing the mango core collection was screened by the UPGMA clustering method, and the core collection was subsequently established. The results showed that the average effective number of alleles (Ne), average Shannon's information index (I), and average Nei's diversity index (H) of 12 pairs of primers was 4.0993, 1.534 and 0.7361, respectively, indicating that the mango germplasm possessed rich genetic diversity. The t-test results of genetic diversity parameters revealed that the core collection constructed by the combination of the locus priority sampling strategy and Nei & Li genetic distance had the highest Ne, H and I among all tested groups, with value of 4.2603, 0.7486 and 1.5855, respectively, demonstrating that the combination was the optimal method for constructing the mango core collection. The established core collection comprised 85 accessions, accounting for 19.72% of the original germplasm. The retention rate of Ne, I and H in the core collection reached 103.93%, 103.35% and 101.45%, respectively, indicating that although the core collection was much smaller in quantity than the original germplasm, it exhibited superior performance in genetic diversity-related indicators. Principal coordinate analysis (PCoA) showed that the distribution of the core collection uniformly covered the distribution range of the original germplasm in the principal coordinate space, suggesting that the core collection could comprehensively retain the genetic diversity characteristics of the original germplasm and had good representativeness.
To clarify the genetic diversity characteristics of pollen morphology and the genetic relationships among pitaya germplasm resources, 63 pitaya germplasm accessions were used as the research materials in this study. Scanning electron microscopy (SEM) was applied to observe pollen micromorphology, 8 traits including polar axis length, equatorial axis length, and polar-equatorial ratio were systematically measured, and the diversity patterns of these traits were investigated through correlation analysis, principal component analysis (PCA), and cluster analysis. The results showed that the pollen grains of all 63 pitaya germplasms were N3P4C3 type, with tricolporate apertures and spiny exine ornamentation. The differences in pollen among the germplasms were mainly reflected in subtle aspects such as shape, size, germinal furrow traits and exine ornamentation. The pollen grains were prolate or subspheroidal in shape. The polar axis length ranged from 58.82 to 101.00 µm, the equatorial axis length ranged from 52.50 to 86.54 µm, the germinal furrow length ranged from 37.03 to 82.25 µm, the germinal furrow width ranged from 1.31 to 8.53 µm, the furrow spacing ranged from 25.14 to 53.88 µm, and the surface spine density ranged from 1.30 to 3.11 per µm². Among the quantitative traits, the coefficient of variation (CV) of germinal furrow width was the largest, while that of equatorial axis length was the smallest. Correlation analysis revealed that polar axis length had an extremely significant positive correlation with germinal furrow length and polar-equatorial ratio, and polar-equatorial ratio had an extremely significant negative correlation with furrow spacing. Cluster analysis showed that the 63 germplasms were divided into 3 major clusters at a Euclidean distance of 20. The first cluster contained 30 accessions including Yuhonglong, the second cluster contained 15 accessions including Yunnan No.5, and the third cluster contained 18 accessions including Bama Red Flesh. This study confirmed that pitaya pollen morphology presents abundant genetic diversity, and established a palynology-based technique for the classification and identification of pitaya germplasms, which can provide important theoretical support for the identification and genetic breeding of pitaya germplasm resources.
Date palm (Phoenix dactylifera), a nutrient-rich crop of significant economic importance, serves as a staple food in many Arab countries and regions, offering considerable potential for further development and utilization. Its genetic resources play a crucial role in driving innovation and enhancing the competitiveness of the date palm industry, garnering increasing attention from the scientific community in recent years. While phased research progress has been achieved, overall studies remain in an exploratory stage. Currently, the global date palm industry faces severe challenges, including climate change, cultivar deterioration, loss of genetic diversity, and threats from pest and disease. Therefore, there is an urgent need to accelerate in-depth research on the preservation, identification, evaluation and innovative utilization of date palm germplasm resources to overcome bottlenecks in achieving simultaneous improvements in yield, stress resistance and quality. This paper systematically reviewed the current status of date palm germplasm resources, encompassing core areas such as resource collection and conservation technologies, identification and evaluation systems, and strategies for innovative utilization. It further examined existing bottlenecks and challenges, proposed targeted solutions, and outlined future directions for development. This study aims to provide theoretical support and strategic guidance for the efficient development and innovative utilization of date palm germplasm resources, thereby enhancing agricultural productivity and optimizing resource management.
The comprehensive effects of different fertilization treatments on soil fertility, enzyme activity and microbial community structure in rubber plantations were systematically investigated to provide a theoretical basis for sustainable nutrient management of rubber plantation soils. Using the rubber clone Reyan 7-33-97 as the research subject, five treatments were set, no fertilization (CK), conventional chemical fertilizer (CF), organic-inorganic compound fertilizer (OF), and two slow-release fertilizers with different release ratios (SF 25% and SF 50%). Soil chemical properties, enzyme activity and microbial community structure were measured to systematically explore the relationships among the factors. Compared with CF, OF treatment significantly increased soil organic matter (35.40%), available phosphorus (40.00%), pH (10.86%) and urease activity (54.84%). SF 25% significantly increased available phosphorus (43.00%) and catalase activity (19.23%). The available phosphorus content in SF 50% treatment showed no significant difference from CF, but was significantly lower than that in OF and SF 25% treatments. Microbial community analysis revealed that there were no significant differences in bacterial and fungal α-diversity across the treatments, but β-diversity analysis showed that fertilization treatments had a significant effect on the fungal community structure. Furthermore, both OF and SF 25% treatments significantly increased the relative abundance of Acidobacteria (93.47%, 64.58%), Chujaibacter (351.56%, 222.53%) and Ascomycota (38.43%, 11.13%) while decreasing the relative abundance of Rozellomycota. The SF 50% treatment significantly decreased the relative abundance of Glomeromycota (53.70%). In conclusion, organic-inorganic compound fertilizer (OF) and slow-release fertilizer (SF 25%) were more effective in improving soil fertility, enzyme activity and microbial community structure, and can be recommended as fertilization strategies for soil health management in rubber plantations.
We have discovered and reported a litchi male sterile line MS1 recently but the characteristics of this male sterile was still unclear. In this study, grafted litchi male sterile line MS1 was used as the experimental materials and all the materials were planted in plastic pots. Anther fertility of the litchi male-sterile line MS1, characterized by off-season flowering, was assessed via morphological observation and paraffin sectioning. The results demonstrated that MS1 produced a low proportion of male flowers during high-temperature seasons. Moreover, both male and female flowers lacked viable pollen grains yet exhibited parthenocarpic ability. This study confirmed the stable male sterility of the MS1 line under high-temperature conditions, which lays the groundwork for determining its sterility type, and provides preliminary strategies for achieving off-season flowering in litchi.
The study addressed the industrial challenges of low flowering rate and reduced yield in off-season pitaya cultivation caused by light and temperature limitations in tropical regions. By leveraging the unique advantages of bio-based carbon quantum dots (CQDs) in enhancing photosynthesis and stress resistance, we systematically investigated the regulatory effects on the photosynthetic characteristics, yield, and fruit quality of pitaya. Using four-year-old Taiwan No. 6 red-fleshed pitaya as the plant material, different concentrations of CQDs (CDS200, CDS250, CDS300, CDS500) and the combinations with nutritional elements (coCDS300, coCDS500, coCDS800) were applied. Through field trials conducted in both summer and winter seasons, the dynamic changes in Rubisco activity, chlorophyll content, flowering characteristics, yield, and fruit quality were systematically investigated. Results demonstrated that during summer, CDS250 and coCDS300 rapidly increased Rubisco activity by 41.05% and 20.46% respectively compared to control, while composite treatments consistently outperformed single CQD applications. In winter, high-concentration treatments (CDS200, CDS250) exhibited a "rapid activation-fast decline" pattern in enzyme activity, whereas composite treatments maintained elevated Rubisco activity for 14 days. Chlorophyll synthesis was significantly enhanced, with summer CDS200 increasing chlorophyll by 43.89% (versus 10.56% for chlorophyll a), and winter composite treatments elevating chlorophyll b proportion to 61.80% without affecting chlorophyll a. Notably, CQDs significantly promoted winter flowering with concentration-dependent effects, where CDS500 showed the most prominent increase (141.80%), followed by coCDS300 and CDS300. Yield analysis revealed CDS300 achieved 115.60% yield increase, while high-concentration CDS200 showed weakest effects, consistent with its regulation on Rubisco activity, chlorophyll content and flowering. The premium fruit ratio reached 80.91% under coCDS300, with all composite treatments outperformed single CQD groups. Winter yield enhancement (58.24%) markedly exceeded summer gains (27.19%). The research demonstrates that bio-based CQDs significantly enhance pitaya yield and quality by regulating photosynthetic systems and reproductive growth, with particularly prominent effects under low-light conditions in winter, providing technical support for off-season cultivation of tropical fruit trees.
To enhance the flower quantity and flowering quality of Phalaenopsis, this study investigated the regulatory effects of spraying 6-BA or multi-stem inducer before and after flower stalk emergence on the flowering traits and lateral branch development of different cultivars. The experiment employed one large-flowered cultivar and six small-flowered cultivars. Treatments included spraying 400 mg/L 6-BA or multi-stem inducer (200×dilution) before stalk emergence and 200 mg/L 6-BA after stalk emergence. Flowering indices such as stalk emergence time, double-stalk rate, multiple-stalk rate, stalk length, flower number, number of lateral branches on the stalk, and bud abortion count were measured. Spraying 6-BA or the multi-stem inducer before stalk emergence significantly promoted stalk emergence in small-flowered cultivars, increasing the double-stalk and multiple-stalk rates (e.g., the multiple-stalk rate of ‘Jinbian linglong’ reached 100%). However, it reduced the number of lateral branches on the stalk in some cultivars. The large-flowered cultivar ‘Daliajiao’ was insensitive to multi-stalk induction, with a double-stalk rate of only 3.3%, but its stalk emergence time was advanced by 20 days compared to the control after pre-emergence 6-BA treatment. Although spraying 6-BA after stalk emergence delayed flowering, it significantly increased the inflorescence length, flower number, number of lateral branches on the stalk, and the length of the longest lateral branch in small-flowered cultivars. It also induced varying degrees of bud abortion, with 'Jinbian kafei' being the most severely affected, showing a bud abortion rate as high as 59.2%. In conclusion, the effects of 6-BA on Phalaenopsis flowering exhibit significant cultivar differences and are dependent on the application timing. Treatment before stalk emergence is conducive to inducing multiple stalks in small-flowered cultivars and improving emergence uniformity, with the multi-stem inducer showing similar effects to 6-BA. Treatment after stalk emergence can optimize the inflorescence structure of small- flowered cultivars but requires attention to the risk of bud abortion. In production, the appropriate treatment timing should be selected based on cultivar characteristics and cultivation objectives.
Phoenix dactylifera L. (Date Palm), with a cultivation history of over 7000 years, ranks among the world's most ancient fruit trees. Renowned for its exceptional tolerance to drought, high temperatures, and salinity, it has become a highly valuable economic crop in arid regions. Advances in agricultural technology and growing awareness of ecological conservation underscore the strategic importance of developing efficient date palm cultivation technologies for food security, ecological protection, and enhanced regional economic benefits. This paper systematically explored the key technologies for high-quality and high-yield date palm cultivation under the synergistic framework of intelligent cultivation and green control. It comprehensively reviewed strategies for optimizing the growth environment, including soil adaptation, water regulation, and light & temperature management. Core high-yield cultivation techniques-such as soil preparation, planting density, precision fertilization, tree pruning, water-saving irrigation, and intercropping models were systematically integrated and summarized. The application status and potential of intelligent technologies, including the Internet of Things (IoT), big data, artificial intelligence (AI), and unmanned aerial vehicles (UAVs), in precision date palm cultivation were discussed. Research progress and optimization directions for propagation techniques, notably offshoot propagation and tissue culture, were analyzed. Furthermore, an Integrated Pest Management (IPM) strategy centered on biological control was proposed as a green pest and disease control approach. The paper would provide prospects for the date palm industry from four key perspectives, ecological environment, cultivation technology innovation, industrial integration, and international cooperation, aiming to offer a solid scientific basis and technical support for the high-quality, efficient, and sustainable development of the date palm industry.
In China, areca palm yellow leaf disease (AYLD) is primarily attributed to infection with phytoplasmas from the 16SrI, 16SrII and 16SrXXXII groups. Currently, detection methods predominantly target the 16SrI group or non-specifically detect all three groups, lacking specific identification methods for the 16SrII group phytoplasmas. To achieve specific detection of 16SrII group phytoplasmas, specific nested PCR primers were designed and screened in this study based on the ribosomal protein (rp) gene sequence of 16SrII group phytoplasmas, and the characteristics and application efficacy of this method were subsequently evaluated. Results showed that the method could accurately distinguish positive samples from healthy ones. In the sensitivity comparison, the sensitivity of the method was higher than that of the universal nested PCR targeting the 16S rRNA and tuf genes. In the specificity evaluation, it showed no cross-reactivity with phytoplasmas from the 16SrI or 16SrXXXII groups, or with other tested areca palm pathogens and endophytic bacteria. In practical application, among 22 areca palm samples collected from Wenchang, Hainan Province, 4 samples were detected as positive; additionally, the method could detect 16SrII group phytoplasmas including Parthenium hysterophorus witches’-broom phytoplasma, Cleome rutidosperma witches’-broom phytoplasma, and peanut witches'-broom phytoplasma, demonstrating good applicability. In conclusion, the nested PCR method established in this study based on the rp gene has good specificity for the 16SrII group areca palm yellow leaf phytoplasmas, and could provide technical reference for field diagnosis and disease monitoring of the 16SrII group areca palm yellow leaf phytoplasmas.
Elucidating the response of rhizosphere soil microorganisms to the invasion of Fusarium in pepper provides a theoretical foundation and technical support for research on pepper rhizosphere microecology, the exploration of superior biocontrol resources, and the targeted control of pepper Fusarium wilt. Rhizosphere soil samples were collected from healthy (CK), mildly diseased (T1), moderately diseased (T2) and severely diseased (T3) pepper plants. High-throughput sequencing and bioinformatics analyses were employed to compare the community structure and diversity of rhizosphere microorganisms and to assess the functional differences. CK had the highest number of unique bacterial OTUs, while T1 had the highest number of unique fungal OTUs. At the genus level, the dominant bacterial genera included unclassified Acidobacteriaceae、unclassified Bacteria、unclassified Rhodospirillales、Gaiella、unclassified Betaproteobacteria、Terrimonas、unclassified Desulfuromonadiaand Fontisphaera the dominant fungal genera included Thermoascus, Mortierella, Apiotrichum, Fusarium, Rasamsonia, unclassified Fungi, Paracremonium, Talaromyces, Debaryomyces and Metarhizium. With increasing disease severity, the richness of both bacteria and fungi initially increased and then decreased, while the diversity showed a trend of initial increase, followed by a decrease, and then a subsequent increase. PCoA results revealed distinct differences in bacterial and fungal communities among the treatments. Linear discriminant analysis (LEfSe) identified 14, 2, 6 and 6 bacteria-specific species at the genus level, respectively, and 12, 10, 7 and 9 fungi-specific species for CK, T1, T2 and T3, respectively. Cross-domain correlation analysis between rhizosphere bacteria and fungi demonstrated that Fusarium was negatively correlated with Acidibacter, Bradyrhizobium and Bryobacter. As disease severity increased, the network parameters of bacterial and fungal community interactions exhibited an initial rise, followed by a decline, and then a subsequent rise. The abundance of potentially pathogenic microorganisms was significantly higher in diseased plants than that in healthy peppers, while the abundance of stress-tolerant microorganisms initially increased significantly and then decreased. The relative abundance of saprotrophs was significantly higher in severely diseased plants compared to healthy peppers, and the abundance of plant pathogens showed a significant increase-decrease-increase trend. Pepper Fusarium wilt significantly altered the characteristics of the rhizosphere soil microbiome. In the early stages of disease, pepper roots likely resist Fusarium infection by recruiting beneficial microorganisms, stimulating bacterial stress tolerance, and enhancing fungal saprotrophic and symbiotic functions. In the middle and late stages, intensified root damage leads to a decline in recruitment capacity, allowing pathogens to dominate and beneficial microbial communities to be suppressed.
Konjac (Amorphophallus spp.) is an important medicine and food economic crop in China, but its industrial development has long been threatened by soft rot disease, known as the konjac ‘cancer’. Hainan is an emerging konjac producing area, but the current epidemiological pattern of konjac soft rot disease and pathogenic bacteria population structure is not clarified. The study was aimed to carry out soft rot disease investigation, pathogen isolation and identification, and to provide a scientific basis for the control of the disease. The survey of konjac soft rot disease in six cities and counties in Hainan showed that the highest incidence rate (46.01%) was found in the third team of Danzhou Experimental Farm, while that of Wenchang planting base is low (8.25%). Combining morphology, molecular biology (16S rDNA, proA, gapA and mdh multigene phylogenetic analysis) identifications and distribution information of pathogens, Dickeya fangzhongdai (88.64% of the total), Pectobacterium aroidearum (6.82%) and P. colocasium (4.54%), were the cause of the disease. Pathogenicity assay showed that D. fangzhongdai was high pathogenicity, and indoor screening showed that 0.3% tetramycin had the best inhibitory effect on D. fangzhongdai, with the lowest inhibitory concentration (MIC) of 1.825 μg/mL, followed by 80% ethacrynicin (MIC of 25 μg/mL) and 25% bromoxynil (MIC of 125 μg/mL). The dynamic changes of defence antioxidant enzymes and malondialdehyde in konjac in response to D. fangzhongdai infestation were determined by pot inoculation experiment. The results showed that the activity of superoxide dismutase (SOD) and peroxidase (POD) reached 182.57 U/g and 300.33 U/g, respectively, after 72 h of infestation, which was 2.27-fold and 7.03-fold higher than that of the control, while the activity of catalase (CAT) peaked at 24 h (1093.67 U/g) and decreased to 658.01 U/g in the later period (72 h). Malondialdehyde (MDA) content increased incrementally with infestation time and increased by 30.51% at 72 h compared to the control, and β-galactosidase (β-GAL) activity continued to rise [97 nmol/(min·g)] and increased by 36.86% compared to the control.
Xisha Islands are located in a low-latitude area that straddles the boundary between the Indian and eastern Asian monsoon systems. The unique and diverse ecosystem provides habitats for numerous microorganisms, generating exceptionally rich microbial resources. Due to the remote geographical locations of most islands and the fact that the coastal vegetation is in the vanguard stage of oligotrophic conditions, the microbial communities may differ from those of islands with complex vegetation. In this study, through the research on the fungal diversity of coastal coral sandy soil in Xisha Islands, two new species of Aspergillus, namely A. paraflavipes and A. ganquanensis, were isolated from the local coral sandy soil samples using potato-dextrose agar. Identifications of new species were carried out based on various methods such as detection of growth rate in plate culture, observation of colony morphology in plate growth, microscopic morphological comparison, and multi-gene combined phylogenetic analysis (ITS-BenA-CaM-RPB2). The results showed that the species exhibiedt taxonomic status and morphological characteristics that are different from those of existing species. By integrating various detection methods and comparison results, they could be regarded as new taxonomic units. A. paraflavipes and A. ganquanensis belonged to the genus Aspergillus, subgen. Circumdati in sect. Flavipedes and sect. Circumdati, respectively. According to the results of the combined phylogenetic analysis of multiple genes, A. paraflavipes in sect. Flavipedes was a separate lineage parallel to the ser. Flavipedes. According to its microscopic morphological structure, it is shown that the conidiomata of A. paraflavipes was very special, and the size of its stipes and vesicles was much smaller than that of other species in the sect. Flavipedes. According to the growth rate detection results, A. paraflavipes could grow at a relatively fast rate (21‒24 mm, 7 days) on Czapek yeast autolysate (CYA) at 40 ℃. Among the ser. Flavipedes similar to A. paraflavipes, only A. ardalensis (growth rate ≤2 mm, 7 days) and A. templicola (4‒8 mm, 7 days) could grow on CYA at 40 ℃. And its growth rate was extremely slow, and none of the other species grow. Based on the results of phylogenetic analysis, microscopic morphological observation and growth rate comparison, it is believed that A. paraflavipes is located in an undiscovered series in sect. Flavipedes. Therefore, we propose to establish a new strain, ser. Paraflavipedes, to accommodate A. paraflavipes. The detailed morphological comparison and the description of the identification results were described in the article. Multi-gene combined phylogenetic analysis showed A. ganquanensis presented a unique branch in the sect. Circumdati, ser. Sclerotiorum, showing similar morphology to those of the species in this series. This study isolated and documented two new species of Aspergillus originated from the Xisha Islands, expanding our understanding of the fungal diversity of the Xisha Islands. Moreover, it is particularly important to record the biodiversity of the ecosystem before human activities affecting it.
As the main organic waste after the cultivation of edible fungi, the resource utilization of mushroom residue is of great significance to the sustainable development of agriculture. Dissolved organic matter (DOM) is the key active component in the decomposition process of mushroom residue, and the dynamic changes of its content and structure evolution directly affect the environmental effect and fertility release of mushroom residue after returning to the field. At present, the research on the evolution law of DOM system at different decomposition stages of mushroom residue is not clear. Especially, the quantitative analysis on the continuous changes of key physical and chemical properties such as DOM aromaticity, molecular weight and humification degree is insufficient, which limits the efficient resource utilization of mushroom residue. Therefore, this study took mushroom residue as the research object, and aiming to reveal its dynamic evolution law by monitoring the changing trend of DOC content, aromaticity, molecular weight and humification degree of DOM in mushroom residue at different decomposition stages (5th, 15th, 30th and 60th days). In this paper, the characteristic spectral parameters of DOM in mushroom residue were systematically measured and analyzed by UV-Vis absorption spectroscopy, including SUVA254, SUVA260, SUVA280, A250/A365, A300/A400, α355, and spectral slope (SR), and the response order of DOM structure was further analyzed by combining with two-dimensional correlation spectrum (2D-COS). The results showed that the DOC content decreased significantly with the extension of the decomposition period, and decreased by 71.05% on the 60th day compared with the 5th day, indicating that the easily degradable organic carbon components in the mushroom residue were preferentially utilized by microorganisms. SUVA254 and SUVA260 decreased at first and then increased, while SUVA280 increased at first and then decreased, indicating that the aromatic components with simple structure in DOM were preferentially decomposed by microorganisms. A250/A365 and A300/A400 gradually decreased during the decomposition process, reflecting the increase of DOM molecular weight and humification degree. α355 decreased significantly, and the SR value was always less than 1, indicating that the DOM of mushroom residue was dominated by external input. 2D-COS analysis showed that the aromatic component (200 nm) was the most sensitive to the decomposition process. To sum up, this study revealed the regular phenomenon that DOM structure tends to be complex and stable in the decomposition process of mushroom residue, which would provide theoretical support for soil carbon sequestration and mushroom residue resource utilization. In the future, with the help of three-dimensional fluorescence and high-resolution mass spectrometry, the composition and transformation path of DOM in mushroom residue could be deeply analyzed, and the correlation analysis between DOM and microbial community function could be strengthened to fully reveal the driving mechanism and long-term ecological effect of DOM transformation of mushroom residue.
Banana has high nutritional and economic value. However, banana is easy to decay after harvest, making preservation difficult. Banana quality is significantly affected by external conditions. Temperature is a key factor in regulating the post-harvest banana ripening quality. Zhongre No. 1 is a new variety resistant to Fusarium wilt with high yield and good quality, which is independently cultivated by our research group. However, its optimal storage temperature has not been clearly defined. Therefore, investigating the effect of different temperature on the post-harvest quality of Zhongre No. 1 is of great significance for the industrialization of the variety. In the study, freshly harvested Zhongre No. 1 banana was ripened at 14 ℃, 16 ℃, 18 ℃, 20 ℃, 22 ℃ and 25 ℃, respectively. Aimed at determining the optimal preservation temperature, the ripening characteristics and starch degradation dynamics were systematically observed, and indicators such as weight loss rate, peel color difference, ethylene release amount, firmness, and starch and sugar content were measured to analyze the effect of storage temperature on the quality indicators. The results showed that higher temperature led to faster fruit color change, weight loss, bunch separation, ethylene release, softening, and starch degradation. Different temperature had little effect on fructose and glucose content but significantly affected sucrose content, with the sucrose content in 22 ℃ and 25 ℃ being significantly higher than that at 14 ℃ and 18 ℃, among which 22 ℃ had the highest sucrose content and 14 ℃ had the lowest. Banana stored at 14 ℃ had the strongest storability, with stable color after turning yellow, making them suitable for long-term storage and transportation. Banana at 22 ℃ ripened quickly and had high sweetness but poor color. Banana at 18 ℃ ripened relatively quickly with golden and plump fruit color, making it more suitable for rapid shelf placement and sales. Banana at 25 ℃ failed to normally lose green color, was easy to bunch separation, and lost commercial value.
In order to clarify the chemical composition characteristics of Blumea balsamifera, screen anti-inflammatory active components, and identify quality markers (Q-markers), and to provide a scientific basis for the quality control of B. balsamifera, a total of 15 B. balsamifera raw herb and 14 powder herb from Zhenfeng, Ceheng and other regions in Guizhou province were utilized for the research. Gas chromatography-mass spectrometry (GC-MS) was employed to establish fingerprint profiles. Hierarchical cluster analysis (HCA), principal component analysis (PCA), and orthogonal partial least squares-discriminant analysis (OPLS-DA) were applied for data processing. To predict the core anti-inflammatory components, a “component-target-pathway” network was constructed using network pharmacology. This prediction was further supplemented by molecular docking verification. A total of 31 compounds were identified. In the GC-MS analysis, 22 and 16 common peaks were calibrated for the B. balsamifera raw herb and powder herb, with sample similarities ranging from 0.971 to 0.997 and 0.991 to 0.999, respectively. The consistency in chemical profiles indicates that the overall quality of the materials is stable. HCA classified B. balsamifera raw herb into 3 clusters and powder herb into 4 clusters. PCA extracted 4 principal components for each sample type, with cumulative contribution rates of 87.137% and 88.495%, respectively, which could effectively characterize sample quality. OPLS-DA identified 5 differential markers (including L-borneol and camphor) from B. balsamifera raw herb and 6 differential markers (including β-caryophyllene and xanthoxylin) from powder herb. Network pharmacology analysis suggested that palmitic acid, 3-octanol, α-eudesmol, γ-eudesmol and perillaldehyde might be the core anti-inflammatory components of B. balsamifera. The components could act on key targets such as EGFR, PTGS2, ESR1, JAK2 and PPARG, and regulate inflammation-related pathways including arachidonic acid metabolism, Th17 cell differentiation, PPAR signaling pathway and JAK-STAT signaling pathway. Molecular docking results showed that the 5 anti-inflammatory components had good binding affinity with target proteins, with binding energies<0 kcal/mol. L-borneol, camphor and γ-eudesmol were identified as the Q-markers of B. balsamifera. The results would provide support for the quality evaluation, anti-inflammatory mechanism research, and efficient resource utilization of B. balsamifera.
To address the issues of low added value in traditional pepper processing, poor fluidity of pepper oleoresin, and the incomplete extraction and emulsification techniques for freeze-dried green pepper oleoresin, this study used freeze-dried green pepper as raw material to prepare pepper oleoresin through ultrasonic-microwave assisted extraction. The volatile components were analyzed by gas chromatography-mass spectrometry (with cyclohexanone as the internal standard), and a mixed emulsifier system of Tween 80 and Span 80 was selected to investigate the effects of pH, ionic strength, and water content on the stability of the emulsion. The results showed that a total of 37 volatile compounds were detected in the pepper oleoresin, mainly monoterpenes and sesquiterpenes, among which β-caryophyllene (210.83 mg/mL) had a relatively high content. The ideal HLB value of the mixed emulsifier was approximately 11. Under the conditions of pH 8.0-9.0, without adding NaCl, and a water content of 95%, the emulsion had a lower particle size and stable physicochemical properties. This study optimized the extraction and emulsification process of freeze-dried green pepper oleoresin, providing technical support for its development and utilization as well as the upgrading of the pepper industry᾿s deep processing.
Camellia oleifera from Hainan possesses unique quality traits. Public attention to both quality of life and nutritional health is increasing, while market oversight of food safety is being continuously strengthened. An in-depth analysis of the soil characteristics in the forestlands of Hainan’s main C. oleifera planting regions and the impact on the elemental composition of the seeds can fully reveal the safety attributes of Hainan C. oleifera seeds. In this study, a total of 11 sample plots were selected from the main C. oleifera planting areas of Hainan. Soil pH, nutrient contents (including organic carbon, organic matter, total nitrogen, total phosphorus, total potassium, nitrate nitrogen, ammonium nitrogen, alkali-hydrolyzable nitrogen, available phosphorus, rapidly available potassium, and slowly available potassium), and heavy metal elements (copper, zinc, and lead) were measured. Simultaneously, elemental indicators in C. oleifera seeds, including nitrogen, phosphorus, potassium, total calcium, total magnesium, total copper, total zinc, and lead, were determined. Duncan’s multiple range test was employed to analyze the differences among various indicators and translocation factors. Pearson correlation analysis was used to examine the influence of soil properties on seed elements. The results indicated that the soils in the main C. oleifera planting areas of Hainan Island ranged from strongly acidic to weakly acidic (pH 3.83-6.90), with significant spatial variation in nutrient content. The DA-1 plot had the highest organic matter content; BT-1 had the highest total nitrogen; HK-1 had the highest total phosphorus and available potassium; and QH-2 had the highest available phosphorus. Notably high levels of copper and zinc were found in the HK-1 plot, while the DA-2 plot exhibited elevated lead content. The contents of the seven nutrient elements in C. oleifera seeds differed extremely significantly (P<0.01), with total calcium showing the largest coefficient of variation (41.2%). Four sample plots, HK-1 (enriched in macronutrients), QH-2 (advantageous in micronutrients), QH-1 (comprehensively balanced), and DA-1 (exhibiting high protein-micronutrient synergy), were identified as high quality resources. The elemental enrichment factors exhibited pronounced plot-specific characteristics, with WZS-1 (for phosphorus), QH-2 (for potassium), DZ-1 (for copper), and CM-1 (for nitrogen and zinc) showing outstanding performance. Correlation analysis confirmed that soil pH was highly significantly positively correlated with the accumulation of magnesium and potassium in C. oleifera seeds, organic matter was strongly associated with seed copper content, and available phosphorus showed significant positive correlations with calcium and zinc contents. This study reveals that maintaining slightly acidic to neutral soil, increasing organic fertilizer application, and balancing phosphorus fertilization are key measures for enhancing the nutritional quality of C. oleifera seeds in Hainan. It would provide a theoretical basis for the selection of high-quality seed resources, targeted cultivation practices, and the optimization of processed product quality.
The study on the ecological suitability regionalization for Coffea arabica in Guangxi is of great reference significance for accurate and effective utilization of ecological and environmental resources, guiding scientific site selection for planting and rational production layout planning. The MaxEnt model and ArcGIS software were used for the modeling of 58 distribution points of C. arabica in Guangxi and 15 environmental factors, and for the prediction of the ecological suitability regionalization and spatial potential prediction in current and future climate scenario. The model’s prediction results had high consistency and reliability, with the AUC of 0.937, the Kappa coefficient of 61.6%, and TSS of 0.738. Climatic limiting factors (coefficient of variation of precipitation seasonality, isothermality, precipitation of coldest quarter, mean temperature of coldest quarter, min temperature of coldest month) played a decisive role in the ecological suitability regionalization of C. arabica in Guangxi. The southwest of Guangxi was the core concentration area for highly suitable area, and important distribution area for moderately and lowly suitable area in current. The top five of total suitable areas, in descending order, were Baise (46.20%), Chongzuo (21.97%), Fangchenggang (8.26%), Nanning (7.33%) and Yulin (6.46%) in the prefecture-level scale. The top five of highly suitable areas, in descending order, were Jingxi (149.58 km2), Xilin (109.77 km2), Napo (62.94 km2), Debao (50.78 km2) and Shangsi (47.31 km2) in the county scale. In the future climate scenario, the total suitable area showed an increasing trend, particularly suitable habitat expanding gradually from the southwest dominant suitable area toward the northeast potential area, with the core distribution areas shifting from the southwest area of Guangxi (Baise, Chongzuo, Fangchenggang and other regions) toward the northeast (Nanning area together with the central and eastern area of Guangxi).
As an important resource plant in tropical regions, Daemonorops jenkinsiana has significant value in the fields of ecology, economy and medicine. This study investigated the community structure of D. jenkinsiana in the secondary forest of Fanjia Provincial Nature Reserve, Hainan. Through sample plot investigation and analysis, the secondary forest in the Fanjia Provincial Nature Reserve of Hainan served as the research object in this study, revealing its community structure characteristics in detail and providing a theoretical foundation for resource protection and artificial cultivation of D. jenkinsiana., providing theoretical insights for the conservation and sustainable utilization of D. jenkinsiana resources. The D. jenkinsiana community was rich in species composition, encompassing a total of 161 plant species belonging to 134 genera and 69 families. In dominant taxa, the dominant families included Fabaceae, Rubiaceae and Arecaceae, accounting for 47.83% of the total species; the dominant genera were Ficus, Ardisia and Calamus, contributing to 13.66% of the total species. Tropical elements dominated both the families and genera of the plants. Among them, there were 47 tropical families, representing 77.05% of the total families, and 108 tropical genera, accounting for 85.71% of the total genera. The dominant species in the arbor layer were Ficus microcarpa, Heptapleurum heptaphyllum, Phoebe sheareri, Cryptocarya concinna, Quercus glauca, Aporosa dioica, Lannea coromandelica, Camphora officinarum, Zanthoxylum nitidum, Engelhardia roxburghiana. The dominant species in the shrub layer included D. jenkinsiana, Rhapis excelsa, Desmos chinensis, Calamus tetradactylus, Maesa japonica, Calamus egregius, Dypsis lutescens, Psychotria rubra, Ancistrocladus tectorius and Dalbergia hupeana. The dominant species in the herb layer were Rhapis excelsa, Alpinia japonica, D. jenkinsiana, Psychotria rubra, Dalbergia hancei, Maesa japonica, Desmos chinensis, Schima superba, Ardisia crenata and Tetracera asiatica. Species diversity was the highest in the shrub layer and lowest in the herb layer. The D. jenkinsiana community not only serves as a valuable natural subject and sample source for regional biodiversity studies but also supports population regeneration and the long-term maintenance of habitats. Furthermore, it represents a vital natural germplasm repository. By establishing sample banks (e.g., seeds, seedlings, tissue samples from mature plants) and digital information databases (documenting provenance, growth environment parameters, morphological traits, and genetic characteristics), the provenance information for D. jenkinsiana across different species and growth stages can be systematically enriched. The effort holds significant importance for the sustainable management of both cultivated D. jenkinsiana plantations and natural liana communities.
