First Report of Bacterial Soft Rot Caused by Pantoea agglomerans on Chinese yam (Dioscorea opposita Thunb.) in China

Chinese yam (Dioscorea opposita Thunb.), which belongs to the family of Dioscorea, is widely naturalized throughout China, due to its high economic and medicinal value. Since 2019, water-soaked lesions were frequently observed in the underground tubers of Chinese yam located in Xinyang City, Henan Province. To identify the causal agent, ten pieces of tissue from the underground tubers with disease symptoms were collected. Those infected tissues (5×5 mm) were crushed in 500 μL sterilized water after surface sterilization and streaked onto Luria-Bertani agar plates. Pale-yellowish, rod-shaped, slimy single bacterial colonies with smooth margin were observed after 24 hours of incubation, and three bacterial colonies (named CY-1, CY-2 and CY-3) were randomly selected for further biochemical and molecular characterization. These bacteria were gram-negative with the cell length of 1.0 to 3.0 μm, width of 0.5 to 1.0 μm, and with peritrichous flagella. Subsequently, the bacteria were biochemically analyzed through BIOLOG (Hayward, CA) and identified as Pantoea agglomerans with 99% probability. Furthermore, the phylogenetic analysis results based on 16S rDNA, DNA gyrase subunit B (gyrB), and RNA polymerase sigma factor (rpoD) showed these three isolates were most closely related to P. agglomerans. The sequence of 16S rDNA, gyrB and rpoD of each strain was submitted to GenBank with the accession numbers MZ541065 MZ541066 and MZ541067 for 16S rDNA; MZ669846, MZ669847 and MZ669848 for gyrB; MZ669849, MZ669850 and MZ669851 for ropD. Pathogenicity test was performed to complete Koch’s postulates. Tubers of Chinese yam were wounded by sterile needle and inoculated with 500 μL 108 CFU/mL bacterial suspension. Sterilized water was used as a control. Five pots were inoculated for each isolate. Water-soaked lesions appeared after five days incubation at 25°C in a biochemical incubator and no lesions were observed on the control. Bacteria re-isolated from the lesions were similar in phenotypic and molecular characteristics to the original isolates. In brief, based on colony morphology, biochemical tests, characteristic sequence analysis, and pathogenicity verification, the pathogen responsible for the soft rot of Chinese yam in Henan Province was identified as P. agglomerans. In China, P. agglomerans has been reported to associate with bacterial soft rot on Chinese cabbage (Guo et al., 2020). To our knowledge, this work is the first report of bacterial rot caused by P. agglomerans on Chinese yam.

Biocontrol Potential of Chitin and Chitosan Extracted from Black Soldier Fly Pupal Exuviae against Bacterial Wilt of Tomato

Globally, Ralstonia solanacearum (Smith) is ranked one of the most destructive bacterial pathogens inducing rapid and fatal wilting symptoms on tomatoes. Yield losses on tomatoes vary from 0 to 91% and most control measures are unaffordable to resource-poor farmers. This study investigated the antimicrobial activities of chitin and chitosan extracted from black soldier fly (BSF) pupal exuviae against R. solanacearum. Morphological, biochemical, and molecular techniques were used to isolate and characterize R. solanacearum for in vitro pathogenicity test using disc diffusion technique. Our results revealed that BSF chitosan significantly inhibited the growth of R. solanacearum when compared to treatments without chitosan. However, there was no significant difference in the antibacterial activities between BSF and commercial chitosan against R. solanacearum. Soil amended with BSF-chitin and chitosan demonstrated a reduction in bacterial wilt disease incidence by 30.31% and 34.95%, respectively. Whereas, disease severity was reduced by 22.57% and 23.66%, when inoculated tomato plants were subjected to soil amended with BSF chitin and chitosan, respectively. These findings have demonstrated that BSF pupal shells are an attractive renewable raw material for the recovery of valuable products (chitin and chitosan) with promising ability as a new type of eco-friendly control measure against bacterial wilt caused by R. solanacearum. Further studies should explore integrated pest management options that integrate multiple components including insect-based chitin and chitosan to manage bacterial wilt diseases, contributing significantly to increased tomato production worldwide.

Isolation, Identification, and Whole-Genome Sequence Analysis of Pantoea Agglomerans Causing Leaf Spot-Hole Disease in Wild Apricot in Xinjiang, China

Wild apricot in Yili wild fruit forest in Xinjiang have been seriously affected by leaf spot-hole disease, with the incidence reaching 100%. To identify the pathogen of apricot perforation in the Yili wild fruit forest, two bacterial strains with strong virulence were obtained by the dilution separation method. The bacterial strains were gram-negative bacteria with yellow colonies, smooth surfaces and neat edges. The results of the pathogenicity test showed that the bacteria could cause symptoms of leaf spot-hole disease in wild apricot, similar to the symptoms in the field, and could cause HR in tobacco. Based on the 16S rDNA gene sequence and multilocus sequence analysis of fusA, gyrB, leuS, pyrG, rpoB and rlpB, combined with the physiological and biochemical characteristics, the isolated strain was identified as Pantoea agglomerans. The pathogen causing bacterial leaf spot-hole disease in wild apricot was determined to be P. agglomerans in the wild fruit forest of Yili, Xinjiang. The whole genome of the pathogen strain GL9-2 was sequenced based on the Illumina HiSeq500 and PacBio RS platforms. The genome size was 4765392 bp, and the G+C value was 55.27%. There was one chromosome and two plasmids in the genome, and 4353 CDs were identified. The annotation results showed that 52 glycoside hydrolase-related genes, 38 bacterial secretory system-related genes and 600 toxin-related genes were predicted.

First Report of Colletotrichum truncatum Causing Anthracnose on Oxalis corniculata in China

Oxalis corniculata L., which belongs to the family Oxalidaceae R. Br., is a very common perennial herb. It is usually planted on bare land or under the forest as landscaping plants, and the whole plant can be used for its medicinal values of clearing heat, detoxification and detumescence. In August 2019, typical symptoms of anthracnose on O. corniculata leaves were observed in the green belt on the campus of Shandong University of Technology (36.81°N, 117.99°E), Shandong Province, China. The disease incidence was above 40% by investigating more than 300 m2 of planting area. Most of O. corniculata are planted under the forest where the disease is found, mainly in the environment with high relative humidity and less ventilation. The infected leaves appeared initially as tawny oval or irregular spots, and then the lesions enlarged gradually until the leaves became dieback or wholly withered, which greatly reduced the landscape effect of O. corniculata. Diseased leaves were collected by cutting into small pieces and sterilized with 75% ethanol for 30 s and 2% sodium hypochlorite (NaClO) for 60 s, rinsed with sterile deionized water for three times. Each air-dried tissue segment was cultured on potato dextrose agar (PDA) and incubated at 25℃ for 5 to 7 days in the dark (Zhu et al. 2013). Fifteen isolates were obtained from 20 symptomatic leaves and the cultures were initially gray white, subsequently became grayish to dark green after 7 days, with copious gray aerial mycelium and black microsclerotia. Three isolates were verified by the amplification of DNA sequences of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), actin (ACT), histone H3 (H3) and chitin synthase (CHS1) genes, using the primer pairs GDF1/GDR1, ACT-512F/ACT-783R, CYLH3F/CYLH3R, and CHS-79F/CHS-234R (Damn et al. 2019, Fu et al. 2019, Liu et al. 2013), respectively. The sequenced genes (GenBank accession no. OK017473, OK159078, OK159076, OK159077) shared 99.62 to 100.00% nucleotide identity with the corresponding genes of Colletotrichum truncatum strain UASB-Cc-10 (GenBank accession no. KF322064.1, KF322055.1, KF322073.1, KF319059.1), respectively, which was consistent with the morphological identification (Sawant et al. 2012). Pathogenicity test was performed with six healthy O. corniculata plants infected with mycelial plugs (about 3 mm in diameter) of three C. truncatum isolates from a 5-day-old culture, while the negative controls on the same leaves were inoculated with sterile PDA plugs. All plants were placed in a greenhouse at 25 to 30℃ with 90% relative humidity. The experiment was conducted three times. Five days later, all inoculated leaves appeared brown sunken spots, whereas no symptoms appeared on negative controls. The same pathogens, C. truncatum, were identified from the inoculated leaves on the basis of morphological and molecular characteristics as described above, confirming Koch’s postulates. To our knowledge, anthracnose caused by C. truncatum on O. corniculata is the first report in China. The discovery of this new disease is beneficial to the application and protection of O. corniculata, a popular landscape and medicinal plant. References: Damn, U., et al. 2019. Stud. Mycol. 92:1. https://doi.org/10.1016/j.simyco.2018.04.001 Fu, M., et al. 2019. Persoonia 42:1. https://doi.org/10.3767/persoonia.2019.42.01 Liu, F., et al. 2013. Mycologia 105:844. https://doi.org/10.3852/12-315 Sawant, I. S., et al. 2012. New Dis. Rep. 25:2. https://doi.org/10.5197/j.2044-0588.2012.025.002 Zhu, L., et al. 2013. J. Phytopathol. 161:59. https://doi.org/10.1111/jph.12019 The author(s) declare no conflict of interest. Acknowledgments: This research was financially supported by the Top Talents Program for One Case One Discussion of Shandong Province and Academy of Ecological Unmanned Farm (2019ZBXC200).

Konya İli Böğürtlen, Ahududu ve Kuşburnu Yetiştiriciliğinde Potansiyel Bir Tehdit: Ateş Yanıklığı Hastalığı

In the present study, totally 49 samples, which showed the symptoms of leaf and shoot blight and cankers with brown discoloration of necrotic tissues on mature branches, were collected from 22 districts and areas of Konya Province between 2017 and 2019. Presence rate of E. amylovora in collected samples, showing symptoms of the disease, from the province was determined to be 40% for blackberry and raspberry and 33% rosehip for rosehip in three years. Bacteria consistently isolated from the diseased tissues were identified on the basis of biochemical, physiological, and molecular tests, comparing with a reference strain of E. amylovora, isolated from blackberry (Kbb 371). Twenty seven representative bacterial strains were gram-negative, rod-shaped, mucoid, fermentative, positive for levan formation and acetoin production, no growth at 36°C, positive for gelatin hydrolysis, and negative for esculin hydrolysis, indole, urease, catalase, oxidase, arginine dehydrolase, reduction of nitrate, acid production from lactose, and inositol. All strains induced a hypersensitive response in tobacco (Nicotiana tobacum cv. White Burley) 24 h after inoculation with a 108 CFU ml-1 bacterial suspension in sterile distilled water. The strains were identified as E. amylovora using the species-specific primers set A/B (1), which amplified a 1-kb DNA fragment in PCR, and the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) method. In order to fulfill the Koch postulates, pathogenicity test was confirmed by injecting bacterial suspensions of 108 CFU ml-1 in sterile distilled water into the shoot tips of 3-year-old blackberry R. fruticosus cv. Chester, raspberry R. idaeus cv. Heritage and rosehip R. canina. All tests were repeated three times. The bacterium was re-isolated from inoculated plants and identified as E. amylovora. Phytosanitary measures are needed to prevent any further spread of the bacterium as potential inoculum sources to new blackberry, raspberry and rosehip growing areas.

First Report of Fruit Rot Caused by Fusarium luffae in Muskmelon in China

Muskmelon (Cucumis melo L.) is one of the most widely cultivated and economically important fruit crops in the world. However, many pathogens can cause decay of muskmelon fruit, including Fusarium spp.. Fusarium spp. are the most important pathogen, affecting muskmelon fruit yield and quality (Wang et al. 2011). In August 2020, fruit rot symptoms were observed on ripening muskmelons (cv. Tianbao) in several fields in Jiyang District, Jinan City of Shandong Province, China. The incidences of infected muskmelon ranged from 15% to 30% and caused an average 20% yield loss. Symptoms appeared as pale brown, water-soaked lesions that were irregular in shape, with the lesion sizes ranging from a small spot (1 to 2 cm) to decay of the entire fruit. The core and surface of infected fruit were colonized and covered with white mycelia. Two infected muskmelons were collected from two fields, 3.5 km apart. Tissues removed from inside the infected fruit were surface disinfected with 75% ethanol for 30 s, and cultured on potato dextrose agar (PDA) at 25°C in the dark for 5 days. Four purified cultures were obtained using the single spore method. On carnation leaf agar (CLA), 3 to 5 septate, falcate, with a pronounced dorsiventral curvature macroconidia with tapered apical cell, and foot-shaped basal cell, measuring 20 to 40 × 3.5 to 4.5 μm. Microconidia and chlamydospores were not observed. These morphological characteristics were consistent with the description of F. luffae (Wang et al., 2019). Because these isolates had similar morphology, two representative isolates (XP11 and XP12) were selected for multilocus phylogenetic analyses. DNA was extracted from the representative isolates using a CTAB method. Nucleotide sequences of the internal transcribed spacers (ITS) (White et al. 1990), calmodulin (CAM), RNA polymerase II second largest subunit (RPB2), translation elongation factor 1-α gene (TEF1) (Xia et al. 2019) were amplified using specific primers, sequenced, and deposited in GenBank (ITS: MW391509 and MW391510, CAM: MW392789 and MW392790, RPB2: MW392797 and MW392798, TEF1: MW392793 and MW392794). Alignments of a combined dataset of ITS, CAM, RPB2 and TEF1 were made using MAFFT v. 7, and phylogenetic analyses were conducted in MEGA v. 7.0 using the maximum likelihood method. The muskmelon isolates (XP11 and XP12) clustered together with the F. luffae reference strain LC12167 (99% bootstrap). To perform a pathogenicity test, 10 μl of conidial suspensions (1 × 106 conidia/ml) were injected into each muskmelon fruit using a syringe, and the control fruit was inoculated with 10 μl of sterile distilled water. There were ten replicated fruits for each treatment. The test was repeated three times. After 7 days at 25°C, the interior of the inoculated muskmelons begun to rot, and the rot lesion expanded from the core towards the surface of the fruit, then white mycelia were produced on the surface. Ten isolations were re-isolated from the infected tissues and confirmed to fulfill Koch’s postulates. No symptoms were observed on the control muskmelons. To our knowledge, this is the first report of fruit rot caused by F. luffae in muskmelon in China. Considering the economic value of the muskmelon crop, correct identification can help farmers select appropriate field management measures for control of this disease.

First report of Curvularia leaf spot of field corn, caused by Curvularia lunata, in Mississippi

In July 2021, foliar symptoms characterized by small, circular, light brown to tan lesions (0.5 to 3 mm diameter) with reddish-brown margins were observed on field corn (Zea mays L.) in two commercial fields in Hinds and Marion counties, Mississippi. Disease severity ranged from 2 to 15% on observed leaves. Symptomatic leaves were sealed in plastic bags, stored on ice, and transferred to the laboratory. Lesions were cut into small sections (≈4 mm2) and surface-sterilized with 70% ethanol for 30 s then rinsed with sterile water. Sterilized sections were transferred to potato dextrose agar (PDA) amended with chloramphenicol (75 mg/liter) and streptomycin sulfate (125 mg/liter) and incubated at 25°C in the dark for 7 days. Gray to brown-black colonies with orange margins and melanized, curved conidia with three transverse septa were observed microscopically (Fig. 1; ×400). Conidia measurements ranged from 15 to 25 μm in length and 7.5 to 12.5 μm in width (x̄= 20 × 9.8 μm; n= 44). Colony and conidia morphology were consistent with previous descriptions of Curvularia lunata (Wakker) Boedijn (Mabadeje 1969; Ellis 1971). Pure cultures were obtained, and DNA was extracted from 9-day old cultures. Two isolates (TW003-21; TW008-21) were selected for sequencing of the internal transcribed spacer (ITS) region using ITS4 and ITS5 primers. The 530-bp consensus sequences were deposited in GenBank under the accession No. OK095277 and OK095278. BLASTn queries of NCBI GenBank showed that the sequences shared 100% identity with C. lunata isolate DMCC2087 from Louisiana (MG971304) and isolate CX-3 from China (KR633084). A pathogenicity test was performed on V4/V5 stage corn plants (Progeny 9114VT2P) grown in 10.2 cm pots in the greenhouse. Plants were transferred to a growth chamber one-week prior to inoculation. The two isolates were grown on amended PDA for 14 days at 25°C and an inoculum suspension was prepared for each isolate by rinsing culture plates with 2 ml of autoclaved reverse osmosis (RO) water amended with Tween 20 (0.01%) and re-suspended into 40 ml of RO water containing Tween 20. The final concentration was adjusted to 2.6×105 conidia/ml (TW003-21) and 2×105 conidia/ml (TW008-21). Ten corn plants were sprayed with 10 ml of inoculum suspension for each isolate using a Preval sprayer with a CO2 canister, and 10 plants were sprayed with water containing Tween 20 only. Plants were incubated in a growth chamber at ≈79% relative humidity and 25°C. Foliar symptoms including small, circular, and tan lesions, similar to those observed in the field, developed 3 days after inoculation. No symptoms were observed on control plants. Following incubation, symptomatic leaves were collected and C. lunata was re-isolated as described above. Colony, spore morphology and DNA sequences from inoculated plants were consistent with the original isolates as described above. The disease has been recently reported in Louisiana (Garcia-Aroca et al. 2018), Kentucky (Anderson et al. 2019), and Delaware (Henrickson et al. 2021). Although Curvularia leaf spot has been observed sporadically in MS corn fields since 2009 (Allen, personal communication), to our knowledge, this is the first official report of the disease in MS. While this disease has been more frequently encountered in MS, the economic impact associated with C. lunata is currently unknown. References Anderson, N. R., et al. 2019. Plant Dis. 103:2692. Chang, J., et al. 2020. J. Integr. Agr. 19:551-560. Ellis, M. B. 1971. Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew, England, p. 452-458. Garcia-Aroca T., et al. 2018. Plant Health Prog. 19:140. Henrickson M., et al. 2021. Plant Dis. First Look. Mabadeje, S. A. 1969. Trans. Br. Mycol. Soc. 52:267-271. † Indicates the corresponding author. E-mail: [email protected]

VIRULENCE GENE PROFILING AND PATHOGENICITY OF Streptococcus agalactiae ISOLATED FROM TILAPIA, Oreochromis niloticus FARMS IN INDONESIA

Streptococcosis caused by Streptococcus agalactiae has become a major disease problem in tilapia culture in Indonesia. This study aimed to detect virulence genes of S. agalactiae during streptococcosis disease outbreaks in several tilapia farms in Indonesia and evaluate the correlation between biotype and virulence genes to bacterial virulence. The presence of virulence genes was determined in 10 strains of S. agalactiae isolated from farm-raised tilapia. Polymerase chain reaction (PCR) protocol was used to determine genes for cylE, hylB, lmb, bib A, PI-2b, fbs A, fbs B, gap, PI-1, and cfb in the template DNA. Pathogenicity test was carried out by intraperitoneal injection of 24 hour-cultured S. agalactiae to tilapia with 108 CFU/fish. Four isolates have seven of virulence genes (cylE, hylB, bibA, PI-2b, fbs A, fbs B, and gap genes), three isolates have six virulence genes (hylB, bib A, fbs A, fbs B, gap, cfb genes), one isolate has four virulence gene (hyl B, bib A, fbs, and cfb genes), and one isolate has one virulence gene (PI-2b gene). None of the isolates has lmb or PI-1 genes. Bacteria with more virulence genes showed higher pathogenicity post injection. Mortality of tilapia injected with b-hemolytic bacteria was 100% within the period of 14-19 hours, while non-hemolytic bacteria was 53.3%-86.6% on 14 days post-injection. Pathological changes associated with the infection by either isolate included melanosis, slow response, anorexia, ocular opacity, gasping, erratic, C-shape, and whirling. It can be concluded that S. agalactiae with more virulence genes show a higher level of pathogenicity. The presence of a virulent gene has the potential to be used as a basis for selecting candidate isolates and designing vaccine compositions as an effort to prevent streptococcosis infection in tilapia in Indonesia.

Phylogenetic distribution of Ralstonia solanacearum species complex populations in potato in Kenya

Ralstonia solanacearum is a pathogen causing bacterial wilt disease of potato, resulting in 70% potato production losses in Kenya. A study was conducted to determine the diversity of Ralstonia solanacearum species complex strains within the main potato-growing regions of Kenya. Potato tubers were collected from different potato-growing regions of Kenya from visibly wilted potato plants, including tomato and irrigation water and cultured for pathogen isolation. Genomic DNA was isolated from 135 purified cultures of RSSC isolates and PCR amplified using multiplex and sequevar primers targeting the endoglucanase partial gene sequences. Pathogenicity test using R. solanacearum strain (phylotype II sequevar I) was done on Kenya Karibu, Shangi, Chulu, Wanjiku and Money Maker cultivars. Phylogenetic analysis of the partial endoglucanase gene identified two genospecies, R. pseudosolanacearum sp. nov (1.5%) and R. solanacearum (98.5%). All R. solanacearum strains clustered in sequevar I and were distributed in all the potato-growing regions surveyed. The cultivars were grown in a greenhouse for two cycles in a randomized complete block design and inoculated with R. solanacearum strain. The severity scores were assessed and the area under disease progress curve (AUDPC) was determined. All the cultivars tested for pathogenicity exhibited wilting symptoms at varying intervals after infection, with none showing complete resistance to R. solanacearum. Cultivar Shangi exhibited minimum disease severity and progression of 41.14% and AUDPC of 1041.7, respectively while Kenya Karibu was the most susceptible with a high progression rate of 68.24% and AUDPC of 1897.5, respectively. Money Maker, Chulu and Wanjiku showed no significant difference in disease severity depicting a simultaneous rate of infection among them. These findings provide valuable information to better understand the pathogen genetic diversity in Kenya and how it spreads.

First Report of Postharvest Fruit Rot Disease of Yellow Peach Caused by Diaporthe eres in China

The yellow peach (Amygdalus persica), is a fruit crop native to China with golden peel and pulp that is of particular interest in the fruit markets. In August of 2021, yellow peaches showing fruit rot symptoms were purchased from a commercial market in Linyi city, Shandong province, China. The symptoms included circular, tan to brown in color, rotten, necrotic lesions, and whitish mycelium mass in the center of the lesions. The infected fruit were surface disinfected with 1% NaClO for 30 s and rinsed with sterile distilled water three times. Diseased tissues from the infected fruits were cut into small segments, aseptically shifted onto potato dextrose agar media containing petri plates and incubated at 25℃ for 5 days. Eight isolates were obtained in total from two isolation experiments. Fungal colonies were initially white, aerial, fluffy at first, and gradually turned brown to gray, with black stromata at maturity. Alpha conidia were aseptate，hyaline，fusiform to ellipsoidal，and ranged in size from 4.16 to 7.76 µm × 1.95 to 3.14 µm (n=30). Beta conidia were aseptate, hyaline, filiform, curved to hamate, and 15.91 to 22.55 µm × 0.82 to 1.66 µm (n=30). The morphological characteristics were consistent with those of Diaporthe species (Gomes et al. 2013). For further identification, a multigene phylogenetic analysis was carried out. The internal transcribed spacer (ITS) region, translation elongation factor 1-α (TEF1-α), histone H3 (HIS), calmodulin (CAL), and β-tubulin (TUB) genes of two representative isolates were amplified by using primers ITS1/ITS4, EF1-728F/EF1-986R, CYLH3F/H3-1b，CAL228F/CAL737R, and Bt2a/Bt2b (Chaisiri et al. 2021), respectively. The sequences were deposited in GenBank (Accession No. OL375154 for ITS; OL406409 for TEF1-α; OL406410 for HIS; OL106407 for CAL; OL406408 for TUB). phylogenetic analyses were conducted using the concatenation of multiple sequences (ITS, TEF1-α, HIS, CAL, TUB) with Maximum Likelihood (ML) in IQtree v1.5.6 (Nguyen et al. 2015). Based on the morphological and phylogenetic characters, the isolates were identified as D. eres. A Pathogenicity test was performed by wound inoculation on harvested fruits of A. persica Variety ‘Jinxiu’. Mature and healthy yellow peaches purchased from Shandong, Anhui, and Hunan Provinces in China were surface sterilized with 1% NaClO solution for 1 minute, rinsed with sterile water and dried. Each fruit was wounded with a sterile scalpel creating a 2-3 mm incision on the peel. A 5 mm agar disc with mycelium grown on PDA at 28℃ for 7 days was placed on wound and sealed with parafilm. Sterile PDA plugs were used as controls. Ten fruit were used for each treatment and the assays were repeated three times. Inoculated fruit were placed in sterilized transparent plastic cans containing wet, sterile paper towels. After 5 days of incubation at 25℃, the same rot symptoms were observed on fruits inoculated with mycelium and the control remained symptomless. D. eres was re-isolated from the lesions of inoculated fruits and the pathogen identification was confirmed by molecular analysis, thus fulfilling complete Koch’s postulates. Although D. eres was previously reported on peach trees of causing shoot blight (Thomidis and Michailides 2009) and stem canker (Prencipe et al. 2017). To our knowledge, this is the first report of D. eres causing postharvest fruit rot of yellow peach in China and it may lead to considerable economic losses in the peach industry should post-harvest disease management practices not be implemented.