First Report of Phomopsis longicolla Associated with Postharvest Fruit Rot of Kiwifruit in China

HomePlant DiseaseVol. 104, No. 2First Report of Phomopsis longicolla Associated with Postharvest Fruit Rot of Kiwifruit in China PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Phomopsis longicolla Associated with Postharvest Fruit Rot of Kiwifruit in ChinaHong Liu, Li Pang, Xun Lu, Ren Cai Wang, and Qian ZhouHong Liuhttp://orcid.org/0000-0001-6168-3579Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha, Hunan, 410128, ChinaSearch for more papers by this author, Li PangCollege of Horticulture and Landscape, Hunan Agricultural University, Changsha, Hunan, 410128, ChinaSearch for more papers by this author, Xun LuAgricultural Science Institute of XiangXi Tujia and Miao Autonomous Prefecture, 416000, ChinaSearch for more papers by this author, Ren Cai WangCollege of Horticulture and Landscape, Hunan Agricultural University, Changsha, Hunan, 410128, ChinaSearch for more papers by this author, and Qian Zhou†Corresponding author: Q. Zhou; E-mail Address: zhouqian2617@hunau.edu.cnhttp://orcid.org/0000-0003-3921-4594Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha, Hunan, 410128, ChinaSearch for more papers by this author AffiliationsAuthors and Affiliations Hong Liu1 Li Pang2 Xun Lu3 Ren Cai Wang2 Qian Zhou1 † 1Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha, Hunan, 410128, China 2College of Horticulture and Landscape, Hunan Agricultural University, Changsha, Hunan, 410128, China 3Agricultural Science Institute of XiangXi Tujia and Miao Autonomous Prefecture, 416000, China Published Online:10 Dec 2019https://doi.org/10.1094/PDIS-08-19-1812-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat China is considered the second producer of kiwifruit (Actinidia deliciosa) worldwide after New Zealand. Postharvest rots caused by fungal pathogens result in severe damage on kiwifruit during storage and transportation. In September 2015, kiwifruit produced in Changsha (28°13′ N; 112°56′ E), Hunan province of China, showed symptoms of postharvest rot, with the incidence of the disease of around 20% of the fruits. The affected fruits had water-drop stain scattered on the dry brown healthy skin, which became soft and lighter in color than the adjacent healthy tissues. White to pale grayish mycelial mats frequently developed on the fruit surface without obvious injury. Using routine fungal-isolation methods and a single-spore purification technique, six single-conidial isolates were obtained from each diseased fruit. The colonies were floccose, dense, and white on potato dextrose agar (PDA). Stromata were black, large, and spreading. Ostiole and rostrate pycnidia with long beaks were observed. Conidia exuded from pycnidia in creamy-to-yellowish drops. Alpha conidia were hyaline, ellipsoidal (4 to 8× 1.2 to 2 µm), and separated (n = 50); beta conidia were hyaline, filiform, and hamate at one end (19 to 37× 0.7 to 1.1 µm) (n = 50). No perithecia were formed on PDA plates incubated for more than 2 months at 22°C. The species identification was determined by sequencing and comparison of the internal transcribed spacer (ITS) regions and β-tubulin (BT) genes using universal primers ITS4/ITS5 and Bt2a/Bt2b, respectively (White et al. 1990). The result showed that six isolates had identical sequences, showing to be the same species. ITS and BT sequences of one representative isolate named Liuyang were submitted to GenBank (accession nos. KU881771 and KU881773, respectively). The ITS sequence showed 99% identity with Diaporthe longicolla (MG832551) (syn. Phomopsis longicolla, Hobbs), and the BT sequence showed 99% identity with P. longicolla (HQ333512). Digestion of ITS PCR-amplified DNA with AluI yielded two restriction fragments of sizes consistent with those reported for P. longicolla (Zhang et al. 1997). Based on the cultural, morphological, and molecular characteristics, the isolate Liuyang was identified as P. longicolla (Hobbs et al. 1985). Pathogenicity was tested on cultivar Cuiyu fruits using 4-mm mycelial plugs (with wound using a sterilized steel needle, 0.5 mm diameter) and spraying conidial suspensions (1 × 106 conidia/ml, without wound). Other fruits were inoculated with sterile PDA plugs or sprayed with sterilized water as controls. All inoculated fruits were incubated at 25°C and 80% relative humidity and placed in a sealed plastic bag. Inoculations were repeated twice. After 10 days, fruits (all with wound and four of 10 without wound) developed white to pale grayish mycelial mats, released water-drop stains, and then became rotted. Control fruits were asymptomatic. P. longicolla was reisolated only from the inoculated fruits. Postharvest fruit rot caused by Phomopsis sp. was reported previously in Italy (Luongo et al. 2011) with the symptom of stem end rot. This is the first report of P. longicolla causing postharvest fruit rot of kiwifruit.The author(s) declare no conflict of interest.References:Hobbs, T. W., et al. 1985. Mycologia 77:535. https://doi.org/10.1080/00275514.1985.12025139 Crossref, ISI, Google ScholarLuongo, L., et al. 2011. J. Plant Pathol. 93:205. ISI, Google ScholarWhite, T. J., et al. 1990. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA. Crossref, Google ScholarZhang, A. W., et al. 1997. Plant Dis. 81:1143. https://doi.org/10.1094/PDIS.1997.81.10.1143 Link, ISI, Google ScholarThe author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Vol. 104, No. 2 February 2020SubscribeISSN:0191-2917e-ISSN:1943-7692 DownloadCaptionSymptom of maize ear rot caused by Fusarium sporotrichioides (B. B. Wang et al.). Photo credit: C. X. Duan. Systemic symptoms of alfalfa mosaic virus (AMV) isolate CaM on leaves of potato (X. Z. Nie et al.). Photo credit: X. Z. Nie. Metrics Downloaded 3,088 times Article History Issue Date: 31 Jan 2020Published: 10 Dec 2019First Look: 4 Oct 2019Accepted: 2 Oct 2019 Page: 579 Information© 2020 The American Phytopathological SocietyKeywordsPhomopsis longicollapostharvest fruit rotkiwifruitThe author(s) declare no conflict of interest.