First report of Fusarium avenaceum causing postharvest decay of European pear in mid-atlantic United States

Authors: Collum, Tamara - Tami; Evans, Breyn; Gottschalk, Christopher

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/17/2022
Publication Date: 7/1/2023
Citation: Collum, T.D., Evans, B.E., Gottschalk, C.C. 2023. First report of Fusarium avenaceum causing postharvest decay of European pear in mid-atlantic United States. Plant Disease. https://doi.org/10.1094/PDIS-08-22-1784-PDN.
DOI: https://doi.org/10.1094/PDIS-08-22-1784-PDN

Interpretive Summary: Pears are harvested prior to ripening and kept in cold storage for several months. While in cold storage, pears are susceptible to many fungal pathogens that can cause fruit decay. In this study, Fusarium avenaceum was identified as a cause of fruit decay on European pears for the first time in the Mid-Atlantic region of the United States. F. avenaceum can produce mycotoxins which is a concern for the fruit processing industry. This research provides new information on a previously unknown pathogen of pear fruit in the Mid-Atlantic region.

Technical Abstract: Fusarium avenaceum has a large host range and has been reported to cause disease on over 80 genera of plants. A F. avenaceum isolate was obtained in December 2021 from a decaying European pear (Pyrus communis L.) ‘Dawn’ with brown, circular, watery, and sunken lesions that was in cold storage at the USDA, Appalachian Fruit Research Station located in Kearneysville, West Virginia. Koch's postulates were conducted using six Bartlett pear fruits that were wound-inoculated with mycelial plugs of the fungus. Brown, circular, watery, and sunken lesions developed within 48 hours after inoculation and incubation at 25°C, while PDA plug inoculated fruit were symptomless. The fungus was reisolated from infected pears and was morphologically identical to the original isolate. Identity of the isolate was confirmed through DNA extraction followed by amplification and sequencing of the ITS and TEF1 gene region. The ITS amplicon (OP007197) matched multiple Fusarium spp. with 100% identity and 100% query coverage including F. avenaceum isolate KJ562378. The TEF1 amplicon (OP007198) showed 99% identity and 99-100% query coverage with F. avenaceum isolates KM189442 and MK512754. F. avenaceum can produce mycotoxins, which is a concern for the fruit processing industry. This is the first report of F. avenaceum causing postharvest decay of European pear in the Mid-Atlantic region of the United States.