First Report of Anthracnose on Peach Fruit Caused by Colletotrichum acutatum in China

Abstract

HomePlant DiseaseVol. 101, No. 9First Report of Anthracnose on Peach Fruit Caused by Colletotrichum acutatum in China PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Anthracnose on Peach Fruit Caused by Colletotrichum acutatum in ChinaY. X. Du, H. C. Ruan, N. N. Shi, L. Gan, X. J. Yang, Y. L. Dai, and F. R. ChenY. X. DuSearch for more papers by this author, H. C. RuanSearch for more papers by this author, N. N. ShiSearch for more papers by this author, L. GanSearch for more papers by this author, X. J. YangSearch for more papers by this author, Y. L. DaiSearch for more papers by this author, and F. R. ChenSearch for more papers by this authorAffiliationsAuthors and Affiliations Y. X. Du H. C. Ruan N. N. Shi L. Gan X. J. Yang Y. L. Dai F. R. Chen , Institute of Plant Protection, Fujian Academy of Agricultural Science, Fuzhou, Fujian, 350013, China; and Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Fuzhou, Fujian, 350013, China. Published Online:27 Jun 2017https://doi.org/10.1094/PDIS-11-16-1568-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Peach (Prunus persica L.) is an economically important fruit crop in most parts of China. Anthracnose of peach fruit causes significant production and economic losses worldwide every year. In South Carolina, anthracnose is caused mainly by species of the genus Colletotrichum, e.g., C. gloeosporioides, C. acutatum, and C. truncatum (Bernstein et al. 1995; Hu et al. 2015). In August 2012, 2013, and 2014, typical symptoms of anthracnose were observed on peach fruits (Baifeng) near maturity in commercial orchards in Ningde, Fujian Province, China. Initially, symptoms appeared as small, light brown, water-soaked, slightly sunken lesions, circular to semicircular spots. As infection continued, the lesions expanded and became dark brown to black and produced wrinkled concentric rings and orange conidial masses in the center of the lesions under high humidity. Ten peach fruits with a single lesion were collected, surface sterilized for 1 min in 0.5% sodium hypochlorite, and rinsed with sterile distilled water. Then 5 × 5 mm necrotic tissue was placed on acidified potato dextrose agar (APDA) and incubated at 25°C for 3 days. The pure cultures were obtained by single conidia isolation. Ten isolates produced pale gray, dense aerial hyphae, in reverse brown with concentric rings at 25°C on PDA after 6 days. Conidia were fusiform-elliptical, sometimes long obclavate to oblong-elliptical, pointed at one or both ends, one celled, aseptate, hyaline, guttulate, and 11.6 to 16.1 × 3.1 to 5.2 μm in size (n = 50). The internal transcribed spacer (ITS) regions of rDNA, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene, β-tubulin (TUB2) gene, and partial sequence of the actin (ACT) gene of representative isolate C1 were amplified and sequenced with primers ITS1/ITS4 (White et al. 1990), GDF1/GDR1, Bt2F/Bt2R, and ACT-512F/ACT-783R, respectively. The ITS consensus sequence (GenBank accession no. KX611163) showed 99% homology with the ITS sequence of C. acutatum (KF928293). The other three consensus sequences (KY049983, KY049984, and KY049982, respectively) revealed 100% identity to the corresponding sequences of C. acutatum in GenBank (JQ948685, JQ950015, and JQ949720, respectively). Based on the above, the isolates were identified as C. acutatum (Sutton 1980; Zhang et al. 2008). To confirm pathogenicity, six mature, healthy peach fruits purchased commercially were surface disinfested with 70% ethanol, and then wounded in four locations on each fruit with a sterile needle. Sterile filter paper disks, dipped in conidial suspension (1 × 105 conidia/ml) or sterile water, were placed on each wound. Three fruits were inoculated per treatment and incubated at 25°C for 2 days at 100% humidity and then another 7 days at 75% humidity. After removal of the filter paper disks 3 days later, symptoms (small, dark lesions) appeared. Six days after inoculation, abundant orange conidial masses were observed. Ten days later, the inoculated areas had decayed. Control fruits remained healthy. C. acutatum was reisolated from symptomatic fruits, and the recovered isolates were identified as C. acutatum through morphological and molecular characterizations. To our knowledge, this is the first report of anthracnose of peach fruit caused by C. acutatum in Fujian Province, China. This disease can seriously affect peach quality and yield, so effective measures should be implemented to control it.