HomePlant DiseaseVol. 105, No. 5First Report of Leaf Spot Disease Caused by Colletotrichum siamense on Vernicia montana in China PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Leaf Spot Disease Caused by Colletotrichum siamense on Vernicia montana in ChinaD. Yang, Y. Zhang, Y. T. Zhang, Q. H. Wang, Y. K. Qi, W. C. Zhu, Y. Liu, and F. Y. HanD. YangKey Laboratory of National Forestry and Grassland Administration for the Protection and Restoration of Forest Ecosystem in Poyang Lake Basin, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, ChinaSearch for more papers by this author, Y. Zhang†Corresponding author: Y. Zhang; E-mail Address: [email protected]https://orcid.org/0000-0002-9907-037XKey Laboratory of National Forestry and Grassland Administration for the Protection and Restoration of Forest Ecosystem in Poyang Lake Basin, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, ChinaSearch for more papers by this author, Y. T. ZhangFujian Normal University, Fuzhou, Fujian 350108, ChinaSearch for more papers by this author, Q. H. Wanghttps://orcid.org/0000-0002-8165-1467Shandong Provincial Academy of Forestry, Jinan, Shandong 250014, ChinaSearch for more papers by this author, Y. K. QiShandong Provincial Academy of Forestry, Jinan, Shandong 250014, ChinaSearch for more papers by this author, W. C. ZhuShandong Provincial Academy of Forestry, Jinan, Shandong 250014, ChinaSearch for more papers by this author, Y. LiuShandong Provincial Academy of Forestry, Jinan, Shandong 250014, ChinaSearch for more papers by this author, and F. Y. HanShandong Agriculture and Engineering University, Dezhou, Shandong 251100, ChinaSearch for more papers by this authorAffiliationsAuthors and Affiliations D. Yang1 Y. Zhang1 † Y. T. Zhang2 Q. H. Wang3 Y. K. Qi3 W. C. Zhu3 Y. Liu3 F. Y. Han4 1Key Laboratory of National Forestry and Grassland Administration for the Protection and Restoration of Forest Ecosystem in Poyang Lake Basin, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China 2Fujian Normal University, Fuzhou, Fujian 350108, China 3Shandong Provincial Academy of Forestry, Jinan, Shandong 250014, China 4Shandong Agriculture and Engineering University, Dezhou, Shandong 251100, China Published Online:7 Apr 2021https://doi.org/10.1094/PDIS-12-20-2609-PDNAboutSectionsView articlePDFSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat View articleVernicia montana is an important oil-producing tree distributed widely in southern China. In May 2019, a leaf spot disease was observed on the foliage of V. montana at Fengshan Forest Farm (25°47′15.56″N, 115°0′9.2″E) in Ganzhou city, Jiangxi, China. The disease incidence was estimated to be above 40%. Leaf lesions initially appeared as small reddish-brown spots (φ = 1.5 to 20 mm) with a distinct yellow halo, which gradually developed to circular or irregular lesions. As the lesions expanded and coalesced, the affected area became necrotic and wrinkled with a reddish-brown color at the center. To identify the pathogen, symptomatic leaves were collected from several trees. Pieces (5 × 5 mm) from the lesion borders were surfaced sterilized in 70% ethanol for 30 s followed by 3% NaOCl for 1 min and then rinsed three times with sterile water. Leaf pieces were placed on potato dextrose agar (PDA) and incubated at 25°C. Pure cultures were obtained from individual conidia by recovering single spores. On PDA, the colonies were white, cottony, and produced dark-green pigmentation near the center. Conidia were single-celled, straight, hyaline, cylindrical, clavate, and measured 4.5 to 6.5 × 15.8 to 19.6 µm (5.2 ± 0.5 × 17.2 ± 1.0, n = 100). Appressoria were brown to dark brown, ovoid to clavate, slightly irregular to irregular, and measured 6.2 to 10.6 × 4.3 to 7.2 μm (7.7 ± 0.9 × 5.9 ± 0.7, n = 100). The internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), beta-tubulin 2 (TUB2), chitin synthase (CHS-1), calmodulin (CAL), and actin (ACT) were sequenced using the primers ITS1/ITS4, GDF/GDR, T1/Bt2b, CHS-79F/CHS-345R, CL1/CL2, and ACT-512F/ACT-783R, respectively (Weir et al. 2012). The obtained sequences were deposited into GenBank with accession numbers MT659663, MT682399, MT682400, MT682398, MT682397, and MT682396 for ITS region, GAPDH, TUB2, CHS-1, CAL, and ACT, respectively. All the sequences showed 99 to 100% similarity with those of Colletotrichum siamense. A neighbor-joining phylogenetic tree was generated by combining all the sequenced loci using MEGA7.0 (Kumar et al. 2016). The isolate GZ-M8 clustered with C. siamense, having 95% bootstrap support. According to the morphological characteristics and phylogenetic analysis, GZ-M8 was identified as C. siamense. To confirm pathogenicity, 30 healthy leaves from 12 V. montana plants (2 years old) grown outdoors were inoculated with a drop of spore suspension (106 conidia/ml) of the isolate GZ-M8 in October. Another 30 healthy leaves were inoculated with sterile water as the control. The leaves were wounded with a sterile needle prick. All the inoculated leaves were wrapped up with black plastic bags to keep them moist for 2 days. The pathogenicity tests were repeated twice. The resulting symptoms were similar to those on the original infected plants, whereas the control leaves remained asymptomatic for 12 days after inoculation. The same fungus was reisolated from the lesions, confirming Koch’s postulates. C. siamense exhibits pathogenicity to many plants across the world including Euonymus japonicas (Wu 2020), Parthenocissus tricuspidata (Zhao et al. 2020), Aloe vera (Azad et al. 2020), and cotton (Salunkhe et al. 2020). To our knowledge, this is the first report of C. siamense associated with leaf spot disease on V. montana in China. This study provides crucial information for epidemiologic studies and appropriate control strategies for this oil plant disease.The author(s) declare no conflict of interest.