To address the Coffea arabica industry in Yunnan being chronically constrained by low-temperature stress, this study systematically conducted the genome-wide identification of the AP2/ERF transcription factor family and functional analysis of the key cold-resistant gene CaDREB2. As the core coffee-producing region in China, Yunnan frequently suffers from severe cold damage such as leaf browning, defoliation, and even branch dieback caused by low-temperature invasions during winter and spring, which directly affects coffee yield and quality. Therefore, based on the genomic data of C. arabica, combined with bioinformatics analysis and Arabidopsis genetic transformation technology, this research deeply elucidated the characteristics of AP2/ERF family members and the cold resistance regulatory mechanism of CaDREB2. First, using HMMER software retrieval and joint verification with multiple databases, a total of 187 CaAP2/ERF family genes were identified in C. arabica (hereafter referred to as CaAP2/ERF) and classified into five subfamilies according to phylogenetic relationships: ERF (97), DREB (51), AP2 (26), RAV (11) and soloist (2). Expression profile analysis showed that the genes in this family exhibited significant tissue specificity, with the largest number of expressed genes in roots (156), while 43 genes reached peak expression at 120 days of fruit development. Further focusing on the core subpopulation responding to low temperature, six CBF genes were screened out, among which CaDREB2 was most significantly up-regulated under low-temperature stress and shared the closest genetic relationship with the Arabidopsis cold-resistant gene AtDREB1A. Functional verification indicated that after constructing CaDREB2-overexpressing Arabidopsis lines and treating them at 4 ℃ for 72 h, the wilting degree of transgenic plants was significantly slighter than that of the wild type. Physiological index measurements showed that the superoxide dismutase (SOD) activity of transgenic lines increased by 85.0% compared with the wild type, proline content accumulated 1.39 times, and malondialdehyde content was significantly lower than that of the wild type, confirming that CaDREB2 enhances cold resistance by strengthening the antioxidant system and osmotic regulation capacity. Molecular mechanism studies revealed that CaDREB2 could simultaneously activate the expression of downstream stress-resistant genes (such as AtCOR15 and AtCOR78) in both ABA-dependent and ABA-independent pathways, forming a synergistic regulatory network. This study completed the genome-wide identification of the CaAP2/ERF family for the first time, clarified that CaDREB2 was the key gene positively regulating coffee cold tolerance, revealed its molecular mechanism of enhancing cold resistance by regulating antioxidant enzyme activity, osmotic regulator accumulation, and downstream multi-pathway gene expression, and would provide core gene resources and a theoretical basis for coffee cold-resistant molecular breeding.

The study was aimed to clarify the population genetic structure and genetic variation characteristics of Pectobacterium carotovorum (the pathogen causing split skin disease) in the main jackfruit-producing areas of Hainan Province, and to provide a theoretical basis for the precise prevention and control of jackfruit split skin disease and the research on its pathogenic mechanism. Eight pathogenic strains of P. carotovorum were isolated from the split skin samples collected from six main jackfruit-producing areas in Hainan, namely Qionghai, Wenchang, Danzhou, Dongfang, Changjiang and Baisha. Whole-genome resequencing was used to analyze the characteristics of single nucleotide polymorphism (SNP) and insertion-deletion (INDEL) variations of the strains. Combined with collinearity analysis, gene family analysis, and phylogenetic analysis, the genetic diversity and geographical differentiation of the strains were investigated. The genome sequencing depth of the 8 strains reached 50×, with coverage ≥68% for all. A total of 74 089 663 SNP loci and 238 283 INDEL loci were identified. Among SNPs, the number of transitions was significantly higher than that of transversions; among INDELs, the number of deletions exceeded that of insertions, and the vast majority of variant loci were homozygous. SNP annotation revealed that variations were mainly distributed in synonymous mutation regions of coding sequences. Strain S9 exhibited significant differences in the number of SNP and INDEL loci as well as mutation regions compared with other strains. Collinearity analysis showed close genomic collinearity between S4 and S5, S7 and S8, and S10 and S15. Gene family analysis identified 4162 orthologous gene groups, including 3106 core conserved gene groups and 42 species-specific orthologous groups, with strains S9 and S14 harboring unique gene clusters. Phylogenetic analysis displayed obvious regional clustering of the strains. Strains from eastern production areas (Qionghai, Wenchang), Danzhou (western), and Baisha-Changjiang (southwestern) formed separate clades respectively. Strain S9 from the Dongfang production area showed significant genetic differentiation from other strains. The P. carotovorum strains associated with jackfruit split skin disease in Hainan exhibit high genetic diversity and a distinct geographical differentiation pattern. Genome-wide SNP and INDEL variations would lay a molecular foundation for dissecting the pathogenic mechanism and evolutionary dynamics of this pathogen.

Ent kaurene synthase (KS) is a key rate-limiting enzyme in gibberellins (GAs) synthesis. The expression of the KS gene in Anoectochilus formosanus (A. formosanus) influences GAs synthesis and plant growth. In this paper, the AfKS gene open reading frame spans 2169 bp, encoding 723 amino acids. The AfKS gene expression was upregulated under red light stress, peaking at 42.38-fold higher than the control after 24 h. However, GAs were downregulated, with significant reductions in GA9, GA7, GA19 and GA8. Under red light conditions, the relative chlorophyll content in A. formosanus decreased (0.85 times), while MDA content increased (1.32 times). Nevertheless, red light stress elevated polysaccharide, total flavonoid, and free amino acid content by 1.13, 1.02 and 1.34 times, respectively. After exogenous GAs added, relative chlorophyll content increased, MDA levels reduced, and polysaccharides, total flavonoids, and free amino acids elevated. This study would provide insights for further elucidating the mechanism of A. formosanus regulating GAs synthesis through KS under red light stress, thereby influencing plant stress resistance and secondary metabolite synthesis.

48 sugarcane varieties (strains) were used as experimental materials in this study to screen sugarcane germplasm with excellent drought tolerance at early growth stage and identify key evaluation indicators for drought tolerance. After 90 days of natural drought stress, a series of drought resistance-related indices at seedling stage of ratoon crop were measured. A comprehensive evaluation of the germplasm drought tolerance was carried out using principal component analysis, cluster analysis and regression analysis. The coefficients of variation of the 12 evaluation indices ranged from 2.62% to 61.53%. Principal component analysis reduced the 12 indices to four comprehensive indicators, with a cumulative contribution rate of 81.53%. Based on the comprehensive evaluation value (D-value) calculated by the membership function method and cluster analysis, the 48 sugarcane lines were classified into four drought tolerance grades, 10 highly drought-tolerant lines, 21 drought-tolerant lines, 14 moderately drought-tolerant lines and 3 drought-sensitive lines. A prediction model for drought tolerance evaluation at seedling stage of sugarcane was established by stepwise regression analysis, D=-1.576+0.078X₁+0.014X₂+0.008X₃+0.003X₄+0.003X₅+0.003X₆+0.001X₇+0.001X₈ (R²=0.923, P<0.01). Eight indices, including soluble protein content, leaf water content, chlorophyll content, shooting rate, leaf area, catalase activity, tillering rate and proline content, were screened as the key indicators for the seedling drought tolerance identification in sugarcane. This study established a comprehensive evaluation system suitable for sugarcane drought tolerance assessment at seedling stage, providing a method reference and basic materials for research of the drought tolerance mechanisms and breeding of new drought-tolerant sugarcane germplasm.

It was aimed to explore the genetic diversity of agronomic traits such as fruits and leaves of seed-grown wampee germplasms on Donghai Island, Zhanjiang, Guangdong, to screen germplasm with excellent comprehensive traits, and to provide theoretical basis and material support for effective preservation, innovative utilization, and variety breeding of wampee germplasm resources in this region. 132 wampee resources were collected from Donghai Island as experimental materials. 21 agronomic traits including single fruit weight, fruit shape index, single fruit seed weight, seed number, soluble solids content, and edibility rate were measured. Correlation, principal components, and clustering analyses were conducted to systematically and comprehensively evaluate the genetic diversity of local germplasm. Among the 132 wampee germplasms, the diversity index for 21 agronomic traits ranged from 1.71 to 2.05, with coefficients of variation ranging from 10.32% to 73.90%. The fruit morphology and quality traits, sugar acid components, and leaf traits of wampees all showed a normal or nearly normal distribution, indicating a rich diversity among different wampee germplasms. Among them, D-malic acid content, oxalic acid content, seed number, seed coat weight, leaf area, ascorbic acid content, and single fruit seed weight showed significant variation, indicating significant potential for genetic improvement. The coefficients of variation for fruit shape index, transverse diameter, and longitudinal diameter were small. Correlation analysis revealed a complex network of associations among fruit size, soluble sugar content, and organic acid content. Cluster analysis divided the germplasms into 8 groups. Group Ⅶ contained 3 non-nucleated germplasms, which possessed the excellent trait of the highest single-fruit weight (10.44 g), making them highly promising unique germplasms for development. The cumulative contribution rate of the first six principal components extracted from principal component analysis reached 78.024%, and a comprehensive scoring model was constructed based on this. Using the components, a comprehensive scoring model was developed, which ultimately resulted in the selection of eight germplasm lines with outstanding comprehensive traits, 86, 88, 82, 106, 63, 61, 39 and 80. The seed-grown wampee germplasm resources have rich genetic diversity. The seedless large-fruited group and eight excellent germplasms selected would provide important parental material for breeding high-yield, high-quality new wampee varieties.

The self-bred cultivar Guangshu 79 from Crop Research Institute, Guangdong Academy of Agricultural Sciences was used as the female parent and the line Guangshu12-44 as the male parent for sexual hybridization to breed a table-use sweet potato variety with superior eating quality and good marketability. Through seedling selection, re-selection, variety comparison tests, and two-year multi-location regional trials, a new high-quality table-use sweet potato variety, Guangshu 133, was developed. The variety produces swollen spindle-shaped storage roots with purplish-red skin and medium-yellow flesh. Root setting is concentrated and uniform, with an average of 5.23 roots per plant and a marketable root rate of 86.28%, indicating favorable commercial quality. In the two-year multi-location regional trials, the average fresh root yield, dry root yield, and starch yield of Guangshu 133 was 29.94 t/hm², 10.71 t/hm², and 6.36 t/hm², respectively, which was 28.95%, 7.03% and 2.75% lower than those of the control cultivar Guangshu 87. Quality analysis showed that the dry matter content of the roots was 34.97%, and the starch content on a dry-weight basis was 591.23 g/kg, including 60.57 g/kg amylose and 530.66 g/kg amylopectin. The content of soluble sugar, reducing sugar, crude protein, total flavonoids, and total phenols was 127.07, 28.65, 36.93, 6.29, 4.38 g/kg, respectively. Eating quality evaluation indicated that, after steaming, the roots had a fine mealy texture, well-balanced sweetness and aroma, and a smooth mouthfeel, with a taste score of 90, significantly higher than that of the control cultivar Guangshu 87 (80). Disease resistance evaluation indicated that Guangshu 133 exhibited moderately resistant to root rot and type Ⅰ sweet potato wilt. In conclusion, Guangshu 133 is a new table-use sweet potato variety characterized by excellent eating quality and good marketability, achieving quality improvement with a moderate trade-off in root yield.

The study evaluated the phenotypic traits of 11 different germplasm accessions of Ludisia discolor, observing qualitative and quantitative traits such as leaf color, vein type, plant height, stem diameter, leaf size, and inflorescence characteristics to establish an efficient in vitro regeneration system for L. discolor. Germplasm H-1 (Meizhou, Guangdong) exhibited outstanding performance in plant height, stem internode length, leaf length, and leaf width, while germplasm 1-21 (hybrid offspring from Bawangling) demonstrated significant advantages in stem diameter and the number of flowers. Germplasm 70 (hybrid offspring from Bawangling) showed the largest flower size, while germplasm 89 (hybrid offspring from Bawangling) exhibited the longest inflorescence peduncle and rachis.The superior germplasm 1-21 was selected and self-pollinated, and undehisced capsules collected after pollination were used as explants. Through asymbiotic germination and in vitro culture, the optimal culture media formulations for each stage were screened. In addition, substrate screening for acclimatization and transplanting was conducted. Further research revealed that the optimal seed germination medium was 1/2 MS+1.0 mg/L 6-BA+0.1 mg/L NAA+30 g/L potato, with a germination rate of 83.67%. For adventitious bud proliferation, MS+3.0 mg/L 6-BA+0.1 mg/L NAA was the most effective, with a proliferation coefficient of 4.45. For rooting and strong seedling cultivation, 1/2 MS+0.1 mg/L NAA+30 g/L banana was the optimal treatment, significantly increasing root number, fresh mass per plant, and leaf number. The highest survival rate during acclimatization was achieved using sphagnum moss as the sole substrate (98.89%), followed by pure pine bark (95.06%) and a mixture of sphagnum moss and pine bark (96.82%). This study established an efficient in vitro regeneration system for L. discolor, encompassing germplasm evaluation, asymbiotic seed germination, adventitious bud proliferation, seedling strengthening and rooting, and domestication and transplantation. The optimal culture media for each stage were identified, providing a theoretical basis and technical support for the large-scale propagation and germplasm innovation of elite L. discolor accessions.

Solanum muricatum is a characteristic and emerging fruit crop experiencing rapid development in Yunnan, and the creation of novel varieties is crucial for the industrial advancement. Protoplast fusion technology serves as an effective approach to achieve interspecific hybridization. To establish an efficient protoplast isolation and fusion system between Solanum muricatum and Solanum lycopersicum, this study utilized S. muricatum Yuanguo No. 2 and S. lycopersicum Jiali as experimental materials. For protoplast isolation, an enzymatic hydrolysis method was employed, focusing on the selection of explants, optimization of enzyme combinations, and determination of hydrolysis duration. For protoplast fusion, the Polyethylene Glycol (PEG) method was adopted, screening suitable conditions based on PEG 6000 concentration and treatment duration. The optimal isolation system for S. muricatum Yuanguo No. 2 involved using callus induced from sterile leaves as the explant, with an enzyme solution consisting of 1% cellulase+0.5% pectinase+0.1% hemicellulase+0.1% macerozyme, hydrolyzed for 12 hours. Under the conditions, the protoplast yield reached 5.09×10⁵ protoplasts/g, with a viability of 71.71%. Conversely, for S. lycopersicum ‘Jiali’, the optimal system utilized sterile leaves as the explant, with an enzyme solution of 1% cellulase+0.5% pectinase, hydrolyzed for 14 hours, yielding 12.37×10⁵ protoplasts/g with a viability of 73.97%. Regarding protoplast fusion, the highest fusion rate (2.26%) was achieved when protoplasts from both species were treated with 35% PEG 6000 for 30 minutes. This study established the optimal source tissues, enzyme combinations, and digestion durations for protoplast isolation from S. muricatum Yuanguo No. 2 and S. lycopersicum Jiali. Furthermore, the appropriate PEG 6000 concentration and fusion duration for protoplast fusion were preliminarily determined. The findings would provide technical support for advancing somatic hybridization between the two species.

Natural rubber is an important industrial raw material and strategic material, and rubber particle size is one of the key indicators affecting rubber quality and processing properties. To clarify the differences and regularity in rubber particle size characteristics between wild germplasms and cultivated varieties of Hevea brasiliensis preserved in the National Rubber Germplasm Repository, 33 wild germplasms and 64 cultivated varieties were selected as research materials in this study. Laser particle size analysis was adopted to determine particle size distribution parameters to investigate the particle size discrepancies between the wild germplasms and the cultivated varieties. The average particle size of the cultivated varieties was significantly smaller than that of the wild germplasms. Among the wild germplasms, the maximum volume-average diameter reached 1.42 μm (accession XJ001337), and the maximum number-average diameter was 0.75 μm (accession XJ005636), which was 1.31 times and 2.27 times the corresponding maximum values of the cultivated varieties [1.08 μm (Hongxing 1) for volume-average diameter and 0.33 μm (Hongxing 1) for number-average diameter], respectively. Wild germplasm, XJ001337 (volume-average diameter: 1.42 μm; area-average diameter: 1.25 μm; length-average diameter: 1.01 μm), XJ001981 (volume-average diameter: 1.41 μm; area-average diameter: 1.24 μm; length-average diameter: 0.98 μm) and XJ005636 (volume-average diameter: 1.34 μm, area-average diameter: 1.10 μm; length-average diameter: 0.92 μm) exhibited conspicuously larger particle sizes in volume-average diameter, area-average diameter and length-average diameter, and could serve as ideal parental materials for modifying rubber particle size of cultivated varieties. Cultivated varieties Hongxing 1 (volume mean diameter: 1.08 μm) and AV385 (volume mean diameter: 1.07 μm) are materials with relatively large particle sizes among existing cultivated varieties, while Huoxing 72-5 (volume mean diameter: 0.55 μm) is the variety with the smallest particle size among all tested germplasms. These two can serve as core parents for the directional improvement of large and small particle size traits within cultivated varieties, respectively. The particle size variation pattern revealed in the study would provide theoretical basis and data support for the utilization of H. brasiliensis germplasm resources, rubber quality improvement and optimization of processing technologies.

To clarify the effects of seed weight of rubber tree clone GT1 on seedling quality and to reveal its roles in seed morphology, water physiology, root development and seedling establishment, GT1 seeds were divided into two groups: above-average weight (T₁) and below-average weight (T₂) based on the average seed weight. The morphological traits, water uptake and water loss dynamics, post-germination root traits, seedling growth traits, rootstock morphology before budding, and new shoot growth after budding between the two groups were compared with statistical analyses using t-tests and Spearman correlation analyses. The width and height were significantly greater in T₁ than in T₂ (P<0.01), and the proportion of T₁ seeds (54.61%) was significantly higher than that of T₂ (45.39%). During the first 1-3 days before germination, the water absorption rate of T₂ seeds was significantly higher than those of T₁ by 58.37%, 52.48% and 47.35% respectively, and T₂ seeds also exhibited faster water loss rates. Compared with T₁, T₂ seeds showed a 37.56% reduction in the number of secondary lateral roots and a 35.75% shorter primary lateral root length after germination. At the stable stages of the first and second whorl leaves, seedling height, stem diameter, leaf length, leaf width and SPAD values were mostly significantly lower in T₂. Before budding, rootstock stem diameter and leaf width in T₂ were significantly reduced by 7.67% and 12.55%, respectively. After budding, new shoot height, stem diameter, leaf length and leaf width in T₂ decreased by 7.08%, 4.66%, 10.25% and 5.46%, respectively, while seed weight had no significant effect on budding survival rate or leaf SPAD value. At sowing, seed weight showed significant weak and moderate positive correlations (r=0.1447~0.3459) with most growth indicators (stem diameter, plant height, leaf length, etc.) at the stable stage of two whorl leaves. In conclusion, seeds with above-average weight in GT1 had obvious advantages in morphology, water regulation, root development and full‑cycle seedling growth. It is recommended to preferentially select seeds above the average weight, and seed grading can be employed to improve rootstock quality and subsequent seedling uniformity, thereby providing theoretical and technical support for standardized and intelligent nursery production of rubber trees.

Arecanut is an important economic crop with both medicinal properties and masticatory use, The color and internal quality of its fresh fruit directly affect its commercial value. Bagging is a common agronomic practice for improving fruit quality, but related research on areca nut remains limited. This study investigated the effects of different bagging treatments on pericarp color and fruit quality by applying four types of bags (single-layer white, single-layer yellow, single-layer red-outside/black-inside, and double-layer yellow-outside/black-inside) at 25, 45 and 65 days after pollination. The results showed that light-blocking paper bags (single-layer red-outside/black-inside, and double-layer yellow-outside/black-inside) effectively promoted pericarp color change. For fresh areca nuts with a harvest period of 120 days, bagging before 45 days after pollination enabled complete color transition from green to bright yellowish. Principal component analysis (PCA) was conducted on the bagging treatments applied. Based on the comprehensive scores, the order of the treatments was ranked as follows, D₂>R₂>R₁>CK₂>D₁>Y₂>D₃>W₂>R₃>W₁>CK₁>Y₁>Y₃>W₃>CK₃. Double-layer yellow-outside/black-inside bagging (D₂) applied at 45 days after pollination was identified as the optimal approach. This treatment resulted in fruits with bright and yellowish, along with significantly reduced contents of polyphenols and tannins, and significantly increased levels of soluble sugars, reducing sugars, and arecoline. The changes contribute to improved taste for fresh consumption while maintaining key bioactive components, thereby enhancing the overall fruit quality. This study would provide technical support and a theoretical basis for producing of high-quality fresh areca nuts.

This study took Keitt mangoes at four different altitude gradients in Huaping County, Yunnan Province as the research objects to explore the effects of altitude on the growth performance, fruit appearance traits, and internal quality of Keitt mangoes, and to provide a scientific basis for determining the optimal cultivation altitude range and production practices. By systematically measuring plant growth indicators, fruit appearance indicators, and internal quality indicators, combined with statistical analysis of data, the influence of altitude on the growth and quality of Keitt mangoes was clarified. As altitude increased, the growth of Keitt mango plants was significantly suppressed, the yield per plant showed a significant downward trend, and the internode length and thickness of the fruiting mother branches also decreased accordingly, resulting in a gradual weakening of the plant growth momentum. On the contrary, the thickness of the petiole and leaves increased significantly, forming structural characteristics adapted to the high-altitude environment, thereby enhancing plant stress resistance in the high-altitude environment. The effect of altitude on fruit appearance was mainly concentrated on the single fruit weight and fruit transverse diameter, both showing a significant downward trend with the increase of altitude, while the fruit shape index slightly increased, and the overall fruit shape remained stable without obvious deformities. In internal quality, the contents of soluble solids, total sugar, and total acid all decreased significantly with the increase of altitude, while the content of crude fiber increased significantly. This indicates that the high altitude environment will inhibit the accumulation of sugar and acid in the fruit, thereby affecting the flavor and quality of the fruit. However, off-peak marketing can be achieved by delaying the ripening of the fruit, effectively improving the market value of the fruit. Comprehensive evaluation based on plant growth, fruit appearance, and internal quality showed that Keitt mangoes at an altitude of 1125.5 m had strong growth potential, stable yield per plant, regular fruit appearance, moderate size, and excellent internal quality, making it the optimal cultivation altitude for Keitt mangoes in Huaping County, Yunnan Province. This study clarified the optimal cultivation altitude of Keitt mangoes in this region, providing a solid theoretical and practical basis for the production of Keitt mangoes at different altitude sections, and further revealing the growth and quality change patterns of Keitt mangoes at different altitudes, thereby effectively avoiding economic losses caused by blind planting and providing support for the high-quality development of the local Keitt mango industry.

Three-year-old seedlings of sugar apple (Annona squamosa L.), canistel [Pouteria campechiana (Kunth) Baehni], Orah mandarin (Citrus reticulata Blanco), guava (Psidium guajava L.), Chinese bayberry (Myrica rubra Lour.), and carambola (Averrhoa carambola L.) were used as experimental materials to investigate the water physiological and secondary metabolic response characteristics of the seedlings in Yuanmou Dry-hot Valley during the dry and rainy seasons. The diurnal dynamics of leaf water potential, chlorophyll content (Chl), flavonoid index (Flav), anthocyanin index (Anth), and nitrogen balance index (NBI) were measured in the dry and rainy seasons, respectively. Combined with environmental factors, physiological plasticity index and membership function analysis, the differences in physiological responses of each tree species were analyzed. The diurnal dynamics of leaf water potential of the six species exhibited a single-valley dynamic pattern in both dry and rainy seasons, and the overall water potential in the dry season was significantly lower than that in the rainy season. There were significant differences in water potential fluctuations among the species in the dry season, with canistel having the smallest daily variation amplitude, displaying stable water status and weak environmental sensitivity. Chinese bayberry had the largest fluctuation amplitude, which was significantly regulated by air temperature and vapor pressure deficit (VPD). Responses of chlorophyll content, nitrogen balance index, and secondary metabolites to the transition between the dry and rainy seasons differed markedly among species. Seasonal differences in chlorophyll content and nitrogen balance index were more pronounced in guava, canistel, and ‘Wogan’ mandarin. Anthocyanin content generally tended to be higher in the dry season, with significantly greater levels in guava, canistel, bayberry, and ‘Wogan’ mandarin than in the rainy season. In contrast, flavonoid content showed relatively limited seasonal variation, with a significant difference observed only in guava. Based on membership function analysis, the six species were classified into three response types;guava as the high-responsive type;sugar apple, Chinese bayberry and carambola as the intermediate type, and Orah mandarincanistel as the conservative type. The young trees of the species formed differentiated water regulation strategies and secondary metabolic response characteristics during the dry or rainy seasons, which could provide a theoretical reference for the introduction, screening, and differentiated cultivation management of fruit trees in the dry-hot valley.

A wild Ganoderma strain was collected from Guilin, Guangxi, China, and a pure isolate designated LZY-1 was obtained through tissue isolation. To evaluate its potential for development and utilization, ITS sequence analysis combined with morphological characteristics was used for taxonomic identification, followed by domestication cultivation experiments to assess polysaccharide content, total triterpenes, and antioxidant activities of the fruiting bodies on different cultivation substrates. Strain LZY-1 was identified as Ganoderma lucidum. Among the tested media, the optimal mother culture and spawn media were potato brown sugar agar and wheat medium, respectively. Among the four cultivation substrate formulations, formulation 1 resulted in the highest biological efficiency (12.46%) and total triterpene content (2.67%), while formulation 2 showed the fastest mycelial growth rate (9.87 mm/d) and the highest crude polysaccharide content (4.28%). When the extract concentration of fruiting bodies was 0.1 g/mL, the total antioxidant capacity ranged from 13.44 to 20.23 μmol/g, and the hydroxyl radical scavenging rate ranged from 27.85% to 48.30%, both reaching the highest values in formulation 4. At a concentration of 0.05 g/mL, the DPPH radical scavenging rate ranged from 17.81% to 31.79%, with the highest value observed in formulation 3 (31.79%). In conclusion, strain LZY-1 exhibited relatively high contents of main bioactive compounds in its fruiting bodies, and its antioxidant activity was significantly affected by cultivation substrates, indicating its promising potential for further development and application.

Pouteria caimito is a perennial evergreen fruit tree belonging to the family Sapotaceae, native to the Amazon region of South America. Owing to its distinctive flavor and high nutritional value, it possesses considerable potential for development and utilization in tropical and subtropical regions. In recent years, with the continued introduction and exploitation of specialty fruit tree resources, China has initiated the introduction, cultivation, and regional adaptability evaluation of P. caimito in Hainan, Fujian, Guangdong, and Guangxi, preliminarily clarifying its growth performance and prospects for wider cultivation. Based on these developments, this review systematically summarized the research progress on the biological characteristics of P. caimito, introduction and cultivation management, formation of flavor and nutritional quality, mechanisms of postharvest browning and storage preservation, as well as the control of major diseases and insect pests. Furthermore, the major bottlenecks and future trends in genetic improvement, physiological regulation of cultivation, and postharvest commercialization were analyzed. From an integrated perspective spanning cultivation traits to postharvest quality regulation, this review highlighted the key scientific issues in P. caimito research and would provide a theoretical basis and future directions for its efficient cultivation, quality improvement, and industrial development.

The leaf dipping method was used to determine the toxic effects of different doses of cassava-derived procyanidin B1 on T. urticae to explore the functions of detoxification metabolism-related genes in Tetranychus urticae and the regulatory roles in the detoxification of the plant secondary metabolite cassava-derived procyanidin B1. Genes associated with the Nrf2 pathway were cloned, and the dynamic changes in expression under sublethal doses of procyanidin B1 were analyzed. The toxic effects of procyanidin B1 on T. urticae were dose- and time-dependent, with 1200 mg/L identified as the threshold dose for toxic effects. At this dose, the mortality rate of T. urticae reached 36.47% after 96 h of treatment, and slightly decreased when the concentration exceeded this threshold. Six genes were cloned, including T. urticae Nrf2, Keap1, and the downstream detoxification enzyme genes CYP392A3, GSTm8, CYP389B1 and CYP315A1. Treatment with 1200 mg/L procyanidin B1 significantly upregulated the expression of Nrf2, Keap1, and most downstream detoxification enzyme genes (GSTm8, UGT201d3, CYP389B1, CYP392A3) at 24 h, among which CYP389B1 showed the highest upregulation (8.17-fold). As the treatment time extended to 48 h and 96 h, the expression of all genes except CYP392A3 and CYP315A1 (which returned to control levels) was significantly suppressed. Analysis of detoxification enzyme activities revealed no significant differences in GST, UGT, and P450 enzyme activities between the short-term treatment groups and the control. However, the activities slightly increased at 96 h, with UGT enzyme activity reaching 1.69 times that of the control. This study confirmed that procyanidin B1 exerted a non-linear dose effect on T. urticae. The findings preliminarily revealed the sublethal effects of procyanidin B1 on T. urticae from the perspective of the expression characteristics of pest detoxification pathway genes, providing a theoretical basis for the breeding of mite-resistant varieties and the development of biocontrol agents based on plant secondary metabolites.

The Eucalyptus urophylla × E. tereticornis clone is widely cultivated in South China due to its rapid growth, high yield, and strong adaptability. In recent years, leaf blight caused by Calonectria eucalypti has occurred frequently, becoming one of the major diseases restricting the healthy development of the eucalyptus industry. Phenylalanine ammonia-lyase (PAL) is the entry-point and key rate-limiting enzyme of the phenylpropanoid pathway, playing an important role in plant defense against pathogen infection. Therefore, systematic identification of the PAL gene family members in E. urophylla × E. tereticornis and characterization of the expression patterns in response to C. eucalypti infection are of great significance for exploring the defense mechanisms of the phenylpropanoid metabolism and identifying key disease-resistance genes in eucalyptus. In this study, the reference genome of the closely related species E. grandis was used in combination with leaf transcriptome data of E. urophylla × E. tereticornis to perform genome-wide identification and expression member screening of the PAL gene family, and the expression changes and physiological responses upon C. eucalypti infection were analyzed. A total of 11 PAL genes, designated EgPAL1-EgPAL11, were identified from the E. grandis genome and distributed across five chromosomes. Nine expressed members with complete PAL domains, designated EuPAL1-EuPAL9, were identified from the leaf transcriptome. The proteins ranged from 669 to 723 amino acids in length, and most were predicted to localize in the cytoplasm. Phylogenetic analysis classified the PAL proteins into four subgroups, among which Group II was an eucalyptus-enriched clade. Transcriptome analysis revealed a significant phylogenetic branch-specific response of EuPAL genes after C. eucalypti infection. EuPAL4-EuPAL9 in Group II were significantly induced and peaked at 24 h, forming a core module in response to pathogen stress, whereas members in Group I and IV remained at low expression levels throughout. Physiological measurements showed that the content of H₂O₂ in leaves increased significantly at 12 h, and both total PAL activity and POD activity peaked at 24 h, largely consistent with the expression dynamics of Group II EuPAL genes. In conclusion, this study revealed the composition characteristics of the expressed PAL members and the dynamic patterns in response to C. eucalypti infection at the gene family level in E. urophylla × E. tereticornis, suggesting that Group II EuPAL members may play an important role in early disease resistance by participating in defense responses such as activation of phenylpropanoid metabolism and regulation of reactive oxygen species. This study would provide a theoretical basis for elucidating the molecular mechanisms of eucalyptus resistance to leaf blight and for screening candidate disease-resistance genes.

Konjac (Amorphophallus spp.) is an important cash crop in China. Its tubers are rich in glucomannan and have broad application prospects in food, pharmaceutical and chemical industries. In recent years, konjac cultivation has developed rapidly in Hainan province, dominated by the highly adaptable bulbiferous konjac. The promotion of rubber-konjac intercropping and reclamation of fallow lands has expanded cultivation to Qionghai, Tunchang, Baisha, Danzhou and other regions, and the industry has initially taken shape on a large scale. However, konjac soft rot, caused by soil-borne pathogens, is prevalent across major global production areas, leading to tuber rot and plant wilting, which severely hampers the sustainable development of the industry. Traditional chemical control methods are prone to causing pesticide residues, environmental pollution and disruption of soil micro-ecological balance, and may induce the development of resistance in pathogens. Therefore, the development of green and efficient biological control technologies is urgent. A number of domestic reviews have summarized the basic achievements in biological control of konjac soft rot in early years. Integrating recent research progress with the regional disease characteristics of Hainan, this paper systematically reviews the advances in biological control of konjac soft rot from three perspectives: pathogen identification, disease epidemiology, and biocontrol technologies. Regarding pathogen identification, it has been established both domestically and internationally that soft rot is primarily caused by bacteria of the genera Pectobacterium and Dickeya, with variations in dominant strains across different regions; in Hainan, D. fangzhongdai is the predominant pathogen. In disease patterns, factors such as high temperatures and humidity, excessive planting density, mechanical damage and poor field drainage can all exacerbate the incidence of the disease. Regarding biological control techniques, various biocontrol microorganisms have demonstrated effective antibacterial activity in both laboratory and field trials. Strains such as Bacillus amyloliquefaciens, B. velezensis and Streptomyces spp. have shown significant efficacy against soft rot, with mechanisms primarily involving niche competition, the production of antimicrobial substances (such as lipopeptides and ketone compounds), the induction of systemic plant resistance, and the promotion of plant growth. Some studies have also explored the synergistic control effects of combining biological control agents with synergistic substances such as organic fertilisers and chitosan, further enhancing control efficiency. It is worth noting that, although some progress has been made in research on the biological control of konjac soft rot both domestically and internationally, there remains a gap in research on the biological control of the pathogen specific to the Hainan region D. fangzhongdai. The screening, identification and field application of relevant biocontrol strains are urgently needed. With advantages such as being environmentally friendly, residue-free and highly sustainable, biological control technologies offer a new pathway for the green control of konjac soft rot. Taking into account the ecological characteristics of Hainan’s tropical island environment and the konjac-rubber intercropping model, future research should focus on identifying highly effective biological control microbial resources against D. fangzhongdai, elucidating the synergistic mechanisms, and optimising the preparation processes and application methods of biological control agents. Efforts should be directed towards resolving key issues such as inconsistent control efficacy and short residual efficacy, thereby promoting the large-scale application and dissemination of biological control technologies within the konjac industry in Hainan and across the nation.

Acmella uliginosa (Sw.) Cass., originated from the tropical regions of Africa, America, and Asia, is discovered as a newly naturalized invasive species in mainland China in recent years. To understand its invasion mechanism, we investigated plant growth and physiological parameters of the invader and the native congener, A. calva (DC.) R. K. Jansen under different light conditions (0%, 25%, 50%, 75% and 95% of shade degree) using potted plants in a glasshouse. Apart from aboveground biomass (unaffected by light level or its interaction with species), plant species, light level and their interaction had a significant effect on all other plant growth parameters of A. uliginosa and A. calva, with the species generally having a greater effect than light level. Under the same light conditions, except for leaf area and net photosynthetic rate, A. uliginosa exhibited significantly higher values in plant height, branch number, inflorescence number, seed number, biomass, and plant nutrient content than those of A. calva, indicating its greater growth rate. With increasing shade levels, the morphological and physiological traits of both species showed similar trends. Some indicators first increased and then decreased, while others continuously decreased or increased. However, under the same light conditions, the absolute effect rates of various indicators in A. uliginosa were mostly superior to those in A. calva, while the absolute inhibition rates were mostly lower, indicating that A. uliginosa has stronger promotion effects or weaker inhibition effects, thus exhibiting stronger light adaptability. All the responses indicated that A. uliginosa had greater growth rate and higher environmental adaptability, which might serve as important mechanisms facilitating its successful invasion.

Acmella radicans (Jacquin) R. K. Jansen is an invasive alien plant species that has been rapidly spreading in Yunnan Province of China in recent years, posing a serious threat to local agricultural production and ecosystems. To explore alternative control methods for this species, a field experiment was conducted to study the competitive effect of Ipomoea batatas (L.) Lam and Helianthus tuberosus L. on A. radicans using the method of de Wit replacement series in this paper. I. batatas and H. tuberosus had greater main stem length, branch length, and biomass than those of A. radicans in monoculture. In mixed culture, the plant height, branch length, branch number, biomass, sexual reproduction, and photosynthetic physiology of A. radicans were significantly suppressed, and the inhibition rates by H. tuberosus were generally higher than those by I. batatas. The relative yield (RY) of I. batatas and H. tuberosus was obviously greater than 1.0, while that of A. radicans was significantly less than 1.0, showing that intraspecific competition was greater than interspecific competition for I. batatas and H. tuberosus, whereas interspecific competition was greater than intraspecific competition for A. radicans. The relative yield total (RYT) of I. batatas vs. A. radicans and H. tuberosus vs. A. radicans was significantly less than 1.0, showing that there was a competitive effect between the two species against A. radicans. The competitive balance index (CBa) of I. batatas vs. A. radicans and H. tuberosus vs. A. radicans was significantly greater than 0, and the CBa of H. tuberosus was obviously higher than that of I. batatas, showing that I. batatas and H. tuberosus had a stronger competitive ability than A. radicans and H. tuberosus had a higher competitive ability than I. batatas. All the results suggested that I. batatas and H. tuberosus could be logical candidate crops for the replacement management of A. radicans.

This study was aimed to explore the differences in volatile components and key aroma compounds of coffee beans processed using different primary techniques from two producing areas in Yunnan. The differences in volatile components were analyzed using Headspace Solid-phase Microextraction-gas Chromatography-mass Spectrometry (HS-SPME-GC-MS) combined with an electronic nose (E-nose). Key aroma compounds were screened based on the relative odor activity value (ROAV), and the sensory quality was assessed using the cupping method. Six coffee samples, ks (washed processing from Kangping), kr (sun-dried processing from Kangping), km (honey processing from Kangping), ns (washed processing from Ning’er), nr (sun-dried processing from Ning’er), and nm (honey processing from Ning’er), exhibited 66, 65, 66, 67, 66 and 64 volatile components, respectively. These primarily included volatile substances such as pyrazines, ketones, pyrroles, phenols, aldehydes, esters, and pyridines. Screening with ROAV≥1 identified 12 key aroma compounds comprising 4 pyrazines, 1 ester, 3 aldehydes, 2 phenols, 1 furan, and 1 pyrrole. Cluster analysis based on the contents of the 12 key aroma compounds showed that samples primarily clustered by production region, indicating that the region had a greater influence on coffee volatile components than the primary processing method. The sensory comprehensive scores were kr>nm>ks>ns>nr>km; in the Kangping region, sun-dried processing yields the best quality, while in the Ningʼer region, honey processing yields the best quality. This study elucidated the intrinsic relationship between primary coffee processing techniques and aroma composition, providing a scientific basis for optimizing processing methods.

It was aimed to systematically compare the structure, physicochemical properties, and digestibility of starches from swollen (CS-P) and non-swollen roots (CS-R) of Millettia speciosa, providing a theoretical basis for their differentiated utilization. Starches were extracted from 5-year-old M. speciosa roots. The multi-scale structures were characterized using SEM, laser particle size analyzer, GPC-MALLS, XRD, solid-state NMR and DSC. Pasting properties, thermal properties and in vitro/in vivo digestibility were also systematically determined. Both starches exhibited A-type crystallinity with similar granule morphology, but exhibited significant differences in multi-scale structures and functionalities. CS-P showed significantly higher amylose content (50.90% vs. 43.23%), lower molecular weight, and higher degrees of short-range order and double helices. Functionally, CS-P displayed higher peak viscosity, setback, and gelatinization enthalpy, indicating stronger thickening and gelling abilities. Conversely, CS-R exhibited better hot paste stability. In vitro, CS-P had a high rapidly digestible starch (RDS) content of 71.05%, whereas CS-R possessed significantly higher resistant starch (RS, 14.45%). In vivo studies in mice confirmed that CS-P induced a rapid glycemic spike, while CS-R produced a slow, sustained glucose release. CS-P is suitable for high-viscosity and rapid-energy food systems, while CS-R, with its high RS content and sustained-release profile, holds greater promise for developing low-glycemic-index functional foods. This study would provide a scientific reference for the grade-specific utilization of M. speciosa starch resources.

This study aimed to investigate the effects of melon cultivars with different disease resistance levels on the rhizosphere microbiome and to explore the potential correlations between predatory protists and functional rhizobacteria. Three melon cultivars with distinct resistance levels, a resistant cultivar (R), a moderately susceptible cultivar (MS), and a highly susceptible cultivar (HS), were used as experimental materials. Rhizosphere soil samples were collected for amplicon sequencing, and bioinformatics analyses were conducted to characterize the changes in rhizobacterial community structure, predatory protist composition, and the abundance of plant growth-promoting rhizobacteria (PGPR) across different resistance backgrounds. Compared with the resistant cultivar, the rhizosphere microbial community structure of the susceptible melon cultivars underwent significant alterations. The Shannon index of rhizobacteria in the resistant cultivar was significantly lower than that in the susceptible cultivars. Compared to the resistant cultivar, the total relative abundance of predatory protists in the rhizosphere of the susceptible cultivars MS and HS decreased significantly by 29.44 and 13.22 percentage points, respectively. Specific taxa (e.g., Ischnamoeba and Filamoeba) were enriched in the susceptible cultivars. Relative to the resistant cultivar, the relative abundance of beneficial bacteria with growth-promoting and pathogen-antagonistic functions (PGPR, such as Sphingobium, Sphingopyxis and Acinetobacter) increased significantly in the susceptible cultivars. Correlation analysis revealed a significant negative correlation between the total relative abundance of predatory protists and that of functional beneficial bacteria. Specific predatory protist taxa (Ischnamoeba and Filamoeba) showed significant positive correlations with beneficial functional bacteria (Acinetobacter, Sphingobium and Sphingopyxis). In summary, the decreased abundance of predatory protists in the rhizosphere of susceptible melon cultivars is closely associated with the enrichment of specific beneficial bacteria, suggesting that aboveground host disease resistance traits may potentially influence rhizosphere microbiome assembly via trophic cascade effects within the soil micro-food web. This study would provide a new perspective for understanding the cascading interaction mechanisms within the “crop-bacteria-protist” tripartite system and offer a theoretical basis for crop health management strategies based on micro-food web regulation.

Soil degradation issues, such as acidification, compaction, and nutrient loss, severely restrict crop growth. Addressing the challenges is of paramount importance for sustaining soil health and ensuring food security. In this study, two typical tropical acidic soils, coastal sandy soil and lateritic red soil, were investigated. Eight treatments were established for each soil type, unfertilized control (CK), conventional fertilization (CF), 0.5% humic acid addition (LHA), 1% humic acid addition (HHA), 0.5% rice straw addition (LRS), 1% rice straw addition (HRS), 0.5% biochar addition (LBC), and 1% biochar addition (HBC). The effects of different organic material amendments on the soil physicochemical properties, enzyme activities, and microbial communities of both tropical acidic soils were systematically evaluated. High-content humic acid application significantly increased soil pH, thereby alleviating soil acidification. High-rate straw application significantly elevated the contents of soil organic carbon (SOC), ammonium nitrogen (NH₄⁺-N), and nitrate nitrogen (NO₃^‒-N). High-quantity biochar amendment significantly enhanced total nitrogen (TN) content, exhibiting the pronounced improvement in the lateritic red soil, TN increased by 41.79% and 31.94% compared with CK and CF, respectively. High-rate additions of all organic materials significantly increased the SOC content in both soils, with biochar showing the superior performance. The SOC content in the coastal sandy soil increased by 54.91% and 44.23% compared with CK and CF, respectively, while that in the lateritic red soil increased by 17.19% and 14.54%, respectively. LHA significantly enhanced catalase activity in the lateritic red soil by 41.51% and 20.49% compared with CK and CF, respectively. Meanwhile, HRS significantly increased the activities of acid phosphatase and urease in both soils, and the catalase activity in the coastal sandy soil. Significant differences were observed in the microbial community structures between the two soils, with bacterial diversity in the coastal sandy soil being significantly higher than that in the lateritic red soil, whereas fungal diversity exhibited the opposite trend. Marked variations were also found in the species composition at both the phylum and genus levels between the two soil types. HRS significantly reduced the diversity of the fungal community in the lateritic red soil. High rates of humic acid, rice straw, and biochar could significantly increase soil organic matter content, whereas the impacts on soil nitrogen and phosphorus varied depending on the material and soil types. Organic materials significantly influenced soil enzyme activities by regulating nutrient supply and the soil microenvironment. Among these, biochar possessed distinct advantages in enhancing soil nutrient retention and supply capacity due to its abundant porous structure and strong adsorption capacity. Meanwhile, humic acid and rice straw could effectively stimulate the activities of extracellular enzymes such as urease and catalase, thereby accelerating nutrient turnover.