HomePlant DiseaseVol. 100, No. 12First Report of Nothophoma quercina Causing Shoot Canker on Chaenomeles sinensis in Korea PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Nothophoma quercina Causing Shoot Canker on Chaenomeles sinensis in KoreaY. H. Yun and M. H. OhY. H. YunSearch for more papers by this author and M. H. OhSearch for more papers by this authorAffiliationsAuthors and Affiliations Y. H. Yun , Department of Microbiology, Dankook University, Cheonan 31116, Republic of Korea M. H. Oh , Department of NanoBioMedical Science, Dankook University, Cheonan 31116, Republic of Korea. Published Online:4 Oct 2016https://doi.org/10.1094/PDIS-06-16-0870-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Chaenomeles sinensis Koehne, Rosaceae family, is widely distributed in Korea, China, and Japan. It has been used as a folk remedy in the treatment of asthma, the common cold, and dry throat. Recently, the medicinal properties of fruit of C. sinensis have been validated by numerous pharmacological studies on anti-influenza, antioxidant, and antidiabetic (Chun et al. 2012). During summer 2015, shoot canker was observed on C. sinensis in Cheonan (36°50′15.0″ N, 127°10′01.8″ E), Korea. Necrotic disease incidence was nearly 5% on young shoots. Symptoms included shoot necrosis, stem browning, and wilted leaves. Shoots showing dieback symptoms were disinfected with 2% sodium hypochlorite, rinsed in sterile distilled water, and air dried. Five randomly selected fragments (5 × 5 mm) of infected shoots were cut and placed on petri dishes containing potato dextrose agar supplemented with ampicillin (100 μg/ml), and then incubated at 25°C in darkness. After 5 days, two whitish colonies were randomly isolated, coded as DUCC512 and DUCC513 for identification. When these isolates were cultured on oatmeal agar (OMA) at 25°C for 7 days in darkness, aerial mycelium was white and floccose to woolly. After 15 days of incubation, abundant black pycnidia were scattered over the medium. One hundred pycnidia and conidia from 15-day-old cultures were used to measure length and width. At 200× and 400× magnification, pycnidia were globose to subglobose and 40 to 110 × 42 to 150 μm. Conidia were aseptate, hyaline to brown, smooth walled, subglobose to oval, and 5 to 7 × 3 to 4.5 μm. These morphological properties correspond to Nothophoma quercina authentic strain CBS633.92 (Aveskamp et al. 2010; Chen et al. 2015). For molecular analysis, the partial β-tubulin gene was amplified from the genomic DNA of the isolates using the primer pair T10 (5′-CGATAGGTTCACCTCCAGAC-3′) and BT12 (5′-GTTGTCAATGCAGAAGGTCTCG-3′). Each of the partial β-tubulin nucleotide sequences was deposited in GenBank under accessions KX184308 and KX184309. BLAST analysis revealed that the β-tubulin sequences of the two isolates shared 100% identity (335/335) with that of N. quercina authentic strain (GU237609). On the basis of morphology and the sequences of β-tubulin gene, the isolates from necrotic lesions on C. sinensis were identified as N. quercina (Chen et al. 2015). The identified colonies were deposited in the Dankook University Culture Collection (DUCC). Pathogenicity tests were conducted on 5-month-old plants. After 7 days of incubation, a mycelial plug (0.3 cm2) cut from the margin of an actively growing colony of the fungus was placed into a shallow wound (0.3 cm2) infected with a sterilized scalpel on the stem base. Inoculated wounds were wrapped with Parafilm. For the control plants, sterile OMA plugs were separately placed into the artificial wounds of the stem base. Five replicates were made for each treatment and the plants were maintained in a greenhouse at 25°C. Six weeks after inoculation, inoculated trees reproduced stem browning and wilting symptoms, while control plants remained healthy. Koch’s postulates were satisfied after reisolating N. quercina from lesions on artificially inoculated stems. N. quercina has been reported to be responsible for stem canker from pistachio and olive trees in the United States and Tunisia (Chen et al. 2013; Taieb et al. 2014). To our knowledge, this is the first report of stem canker caused by N. quercina on C. sinensis in the Republic of Korea as well as other countries. This host plant is widely used for medicinal purpose in Asia. Therefore, our report would be useful information for the management of C. sinensis.