European plum (Prunus domestica) orchards in the Kashi region, Xinjiang, China, suffer from fruit brown spot disease. The disease typically appears as red spots on the fruit surface that expand into brown necrotic lesions; affected fruit flesh can shrink, and fruits can harden and drop. We isolate and identify pathogens associated with this disease in this plum from five Kashi counties. Of 210 fungal isolates obtained through standard tissue isolation, Alternaria accounted for 84.8%, with the remainder comprising species of Aspergillus (9.5%), Diplodia (3.3%), and Neoscytalidium (2.4%). Using PCR amplification and sequencing of five loci, pathogens were identified using multi-gene phylogenetic analyses, combined with observations of colony and spore morphology. Multi-locus sequences of Alternaria isolates were highly homologous to those of the Alternaria alternata type strain, and we refer them to an A. alternata species complex. Pathogenicity tests confirm that Alternaria isolates reproduce brown spot symptoms on European plum fruits. By demonstrating that Alternaria is the primary pathogen causing brown spot disease in European plum in Xinjiang, we clarify both the fungal species composition and taxonomic placement of the dominant pathogen associated with this disease.

Little is known about the fungal pathogens responsible for fig (Ficus carica L.) branch canker in the Kashi region of Xinjiang, China. Using a combination of morphological characterization and multilocus sequence analyses of ITS, TEF1-α, and RPB2, we identified fungal isolates obtained from cankered fig branches collected in commercial orchards in this region. The pathogenicity of representative isolates was evaluated by artificial inoculation of fig branches under natural field conditions. Two dominant fungal species, Fusarium proliferatum and Alternaria alternata, were consistently isolated from diseased tissues. In inoculation assays, both species induced typical branch canker lesions similar to those observed in the field. Lesions caused by F. proliferatum were generally larger than those induced by A. alternata. The original pathogens were successfully re-isolated from the inoculated branches, thereby fulfilling Koch’s postulates. This study represents the first report of F. proliferatum and A. alternata as causal agents of fig branch canker in Xinjiang and expands the known spectrum of pathogens associated with fig branch diseases. These findings provide a scientific basis for improved disease monitoring and the development of sustainable management strategies in local fig orchards.

European plum (Prunus domestica L.) is widely cultivated worldwide, with China producing 6.8 million t annually (55% of the global total output). However, the Kashgar region of Xinjiang, China’s primary production area, has experienced outbreaks of brown spot disease caused by Alternaria alternata (Fr.) Keissl. Outbreaks of this disease severely hinder both domestic and global development of the European plum industry. Because this pathogen has a strong latent infection capability during the early stages of disease development, its early detection is important. We develop two detection methods targeting the ITS sequence of A. alternata: LAMP-Cresol Red chromogenic visible endpoint detection and LAMP-SYBR Green I real-time fluorescent detection. Both methods demonstrate high specificity for A. alternata, enabling stable detection of the pathogen in various plant samples; detection limits reach the femtogram (fg) level, significantly surpassing conventional PCR detection capabilities. Development of these highly efficient and precise early detection methods provides a solid foundation for sustainable development of China as a global hub of the European plum industry, and contributes significantly to global disease prevention, control, and industrial stability for this crop.

Albizia julibrissin is an ecologically and economically significant tree species in the arid regions of Xinjiang, China, valued for its ornamental, medicinal, and environmental functions. In recent years, symptoms of canker disease have been observed on A. julibrissin across multiple locations in Xinjiang, raising concerns about tree health and survival. During the 2023 and 2024 growing seasons, symptomatic branch and trunk samples were collected from three representative regions (Aksu, Kashi, and Tumushuk), where field incidence of canker disease ranged from 16 to 20% based on visual assessments. A total of 128 fungal isolates were obtained from 85 symptomatic samples. Among these, 112 isolates belonged to the Botryosphaeriaceae family, with Botryosphaeria dothidea (81.3%), Diplodia seriata (10.7%), and Neoscytalidium dimidiatum (8.0%) being the dominant species consistently recovered from canker lesions. The main fungal species were identified through phenotypic observations; multilocus DNA analysis targeting the internal transcribed spacer, beta-tubulin, and translation elongation factor gene regions; and pathogenicity testing. Pathogenicity assays were conducted by inoculating mycelial plugs onto wounded branches of healthy A. julibrissin saplings under controlled conditions. Disease progression was monitored, and virulence was quantified based on lesion length. Results confirmed that B. dothidea, N. dimidiatum, and D. seriata are the primary causal agents of A. julibrissin canker disease in Xinjiang, with B. dothidea being the most frequently isolated and most virulent species. This is the first report of these pathogens causing canker on A. julibrissin in Xinjiang, providing a foundation for further studies on disease epidemiology and control in arid regions.

Pear canker, caused by Cytospora pathogens, is a devastating branch and trunk disease threatening the sustainable development of the fragrant pear industry in Korla, Xinjiang, China. Owing to the pathogen’s latent infection capability and the inconspicuous nature of early symptoms, symptom-based diagnosis is inadequate for early warning and precision management. Here, we developed a hybrid LAMP-CRISPR/Cas12a fluorescence detection system targeting Cytospora pyri and its closely related congener C. mali, the dominant Cytospora pathogens associated with pear canker. LAMP primers and Cas12a crRNA recognition sites were designed from conserved sequences of the β-tubulin (TUB2) gene, enabling rapid isothermal amplification and sequence-specific secondary confirmation. The optimized LAMP module amplifies the target within 30 min at 65 °C, and the CRISPR/Cas12a module produces stable fluorescence after approximately 15 min of trans-cleavage at 37 °C. The system yields positive signals for both C. pyri and the closely related C. mali, with no cross-reactivity against other Cytospora species or common fruit tree pathogenic fungi, supporting rapid screening of pome fruit canker pathogens. The limit of detection is 1 copy/μL of target template. Validation using Cytospora strains from diverse geographic and host origins demonstrated complete concordance between LAMP gel electrophoresis, CRISPR/Cas12a real-time fluorescence detection, and UV-assisted visual evaluation. Preliminary results from field-collected Korla fragrant pear branch and trunk samples were consistent with conventional PCR, supporting applicability to orchard samples. By integrating rapid isothermal amplification, secondary sequence verification, and simple visual evaluation, this system provides a robust platform for early screening, pathogen surveillance, and precision management of Cytospora canker in Korla fragrant pear orchards.