Stem rot disease poses a significant challenge in passion fruit production, necessitating the identification of resistant genes for the development of stem rot resistant varieties. In this study, we conducted artificial inoculation of Fusarium solani on leaves of two passion fruit varieties, 'Huangjinguo' and 'Ziguo 7'. Leaf samples were collected at 0 h, 24 h, and 48 h post-inoculation for RNA-sequencing (RNA-seq) analysis, and 3 370, 4 464, and 3 974 differentially expressed genes (DEGs) were identified at these stages. Gene Ontology (GO) analysis revealed associations with functions such as response to reactive oxygen species (ROS), response to hydrogen peroxide, and protein complex oligomerisation. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis highlighted the enrichment of DEGs in the phenylpropanoid biosynthesis pathway, including genes such as ZX.06G0025070, ZX.01G0064640, ZX.04G0011040, ZX.05G0011380, all implicated in lignin biosynthesis. Weighted gene co-expression network analysis (WGCNA) identified three modules significantly associated with passion fruit stem rot resistance. Network analysis highlighted ZX.08G0013660 as the gene with the highest connectivity in these modules, featuring a leucine-rich repeat domain. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) analysis further validated ZX.08G0013660 and other genes as potential candidates for passion fruit stem rot resistance. Overall, genes related to ROS, phenylpropanoid biosynthesis and leucine-rich repeat domain protein likely play critical roles in passion fruit stem rot resistance. This study provides new insights for breeding passion fruit varieties resistant to stem rot disease.

Violet passion fruit (Passiflora edulis Sims) is an important tropical and subtropical perennial evergreen vine with large-scale cultivation in Guangxi, China. Between May and September 2020, anthracnose symptoms occurred on passion fruit (cultivar Tainong No. 1) in Xingye county (22°77'13″N, 110°07'80″E) in Guangxi province, China. The disease incidence varied from 25 to 60% in different orchards. Initial symptoms on young fruits appeared as multiple tiny water-soaked, oval to irregular pale greenish spots. As the disease progressed, the lesions became medium brown, with sunken cavities. Under humid conditions, acervuli containing masses of conidia and dark setae were found on the lesions. The affected fruits became shriveled. Tissue pieces (5 × 5 mm) were cut out from infected fruits, surface sterilized in 75% ethanol for 15 s and 0.1% HgCl2 for 2 min, washed three times with sterile water, placed onto potato dextrose agar (PDA), and incubated at 28 °C for three days. Of the 29 Colletotrichum isolates obtained , the isolate B13 was selected for morphological characterization. B13 was purified by single spore isolation and incubated on PDA at 25°C under continuous fluorescent light irradiation, producing white to pale yellow colonies with dense aerial mycelia. The reverse side of the colony was pale yellowish to olive. Conidia were hyaline, unicellular, straight, cylindrical, with both ends slightly round or one end round and the other slightly pointed, measuring 10.5 to 18.8 (average 16.4) × 5.4 to 7.2 (average 6.3) µm (n = 50). Appressoria were light brown to dark black, smooth-walled, lobed, often with a roundish outline, sometimes also triangular, 7.2 to 10.9 (average 9.1) × 6.8 to 9.2 (average 8.2) µm (n = 50). Morphological characteristics of the isolate matched those of Colletotrichum brasiliense (Damm et al. 2012). The internal transcribed spacers (ITS), actin (ACT), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and beta-tubulin (TUB2) genes of strain B13 were sequenced using the method and primers of Damm et al. (2012). Sequences of the amplified DNA regions were submitted to GenBank (ITS: MW198820; ACT: MW266083; GAPDH: MW266084; and TUB2: MW266085). A concatenated maximum likelihood phylogenetic tree was built using MEGA 7.0.21 in which B13 clustered with C. brasiliense and clearly separated from other Colletotrichum spp. Pathogenicity of B13 was assayed using one-year-old plants of violet passion fruit cultivar 'Tainong No. 1'. Conidial suspensions were prepared from 7-day-old cultures grown on PDA at 28°C Sterile distilled water was used to dislodge conidia from the culture dish and the conidial concentration was adjusted to 1 × 106 spores mL-1 using a haemocytometer. Fruits were rinsed with sterilized water and wounded with a sterile needle at three locations. Three fruits were inoculated by spraying with 20 mL of the conidial suspension. Control fruits were sprayed with distilled water. Fruits were then covered with plastic bags to maintain high relative humidity . After 9 days, all inoculated fruits developed brown spots with sunken cavities, resembling symptoms observed in the field, and controls remained symptomless. Fungal cultures with phenotypic features similar to C. brasiliense were re-isolated from the symptomatic fruits, verifying C. brasiliense as the causal agent of the disease based on Koch's postulates. C. boninense, C. gloeosporioides, C.queenslandicum, C. brevisporum, and C. karstii were reported as causal agents of anthracnose on passion fruit (Júnior et al.2010; Power et al. 2010; James et al.2014; Du et al.2017; Ran et al.2020). To the best of our knowledge, this is the first report of C. brasiliense causing anthracnose on passion fruit in China.

Cassava/peanut intercropping is a popular cultivation method in southern China and has the advantages of apparently increased yield and economic efficiency compared with monoculture, however, the ecological benefits of this method are poorly understood. This study aimed to investigate the effects of intercropping on the physicochemical properties and microbial community structures of soil. Field trials were performed to determine the effects of cassava/peanut intercropping on rhizospheric soil nutrient content, enzyme activities, microbial quantity and microbial community structure. The microbial community was characterized by 16S rRNA tag-based high-throughput sequencing on the Illumina MiSeq platform. Results showed that cassava/peanut intercropping could improve the physicochemical properties of rhizospheric soil by increasing the available nutrient content, pH, bacterial quantity, and some enzyme activities and by altering the microbial community structure. 16S rRNA gene sequencing demonstrated that the microbial community structure varied between the intercropping and monoculture systems. Nitrospirae, Verrucomicrobia and Gemmatimonadetes were more abundant in the intercropping system than in the monocultures. Redundancy analysis (RDA) revealed that the abundances of DA101 , Pilimelia and Ramlibacter were positively correlated with environmental parameters such as available nitrogen and pH, and these were dominant genera in the rhizospheric soil of the intercropped peanut plants.

Postharvest anthracnose of citrus, caused by the fungus Colletotrichum gloeosporioides, leads to significant economic losses. There is a growing need for effective biological control agents to manage this disease. In this study, a bacterial strain (T226) with antagonistic potential was isolated from sugarcane rhizosphere soil. It was identified as Lysobacter enzymogenes through a polyphasic approach, encompassing 16S rDNA phylogenetic analysis (with 100% bootstrap support), morphological observation, and physiological and biochemical characterization. Strain T226 demonstrated strong and stable antagonistic activity against C. gloeosporioides. Its efficacy remained consistent over eight continuous subcultures on artificial media, indicating high metabolic stability. In vivo biocontrol assays confirmed its potency. Specifically, artificial stab inoculation tests showed a disease control efficacy of 78.2%, while under conditions of natural infection, T226 achieved control efficacies of 61.3% at 20 and 60 days post-application. To our knowledge, this is the first report identifying Lysobacter enzymogenes as a highly effective biocontrol agent against citrus postharvest anthracnose. The high stability and significant efficacy of strain T226 underscore its considerable potential for practical application in postharvest protection during citrus storage.

Plant growth-promoting rhizobacteria (PGPR) offer a sustainable alternative to chemical fertilizers in rice production, yet the mechanisms underlying multifunctional growth promotion by individual strains remain insufficiently characterized. In this study, strain ST2023006 was isolated from sugarcane rhizosphere and systematically characterized through phenotypic assays and whole-genome sequencing. The strain was identified as Pseudomonas chlororaphis based on morphological, physiological, biochemical, and multilocus sequence analyses. It exhibited tolerance to temperature (25-37 ℃), pH (5.0-9.0), and salinity (≤2% NaCl). ¹⁵N isotope dilution analysis revealed nitrogen fixation contribution rates of 13.4% and 9.72% to rice roots and shoots, respectively. Pot experiments demonstrated that inoculation significantly promoted growth in two rice varieties, increasing plant height by up to 86.6%, while enhancing root surface area, root volume, and biomass accumulation. In vitro antagonism against Rhizoctonia solani and quantitative IAA analysis (59.44 µg·mL⁻¹) provided experimental support for genome-predicted biocontrol and IAA production traits. Whole-genome sequencing revealed genes potentially associated with nitrogen fixation (nifU, fixI), nutrient mobilization (potassium/zinc solubilization, siderophores), phytohormone synthesis (IAA), stress tolerance (heavy metal resistance, heat/cold shock proteins), and complete biosynthetic gene clusters for the antifungal compounds pyrrolnitrin, phenazine, and hydrogen cyanide. These findings indicate that P. chlororaphis ST2023006 is a promising multifunctional PGPR candidate with demonstrated plant growth-promoting effects and experimentally supported genomic potential for biocontrol.