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ARS Home » Northeast Area » Frederick, Maryland » Foreign Disease-Weed Science Research » Research » Publications at this Location » Publication #403667

Research Project: Discovery and Development of Microbial-Based Biological Control Agents for Use Against Invasive Weeds in the United States

Location: Foreign Disease-Weed Science Research

Title: Corynespora cassiicola isolates recovered from Japanese honeysuckle (Lonicera japonica) are capable of causing target spot on tomato and cotton

item Fulcher, Michael

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/15/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Japanese honeysuckle (Lonicera japonica) is a non-native invasive perennial weed that colonizes disturbed sites throughout the eastern and southern United States. Surveys for endemic pathogens of honeysuckle with biological control activity were conducted in Maryland in 2021, and an unknown fungal species was recovered from necrotic leaf spots. The species identity, pathogenicity, and host specificity of five isolates were determined. Based on morphological and DNA sequence evidence, the fungus was identified as Corynespora cassiicola, causal agent of target spot on diverse crop species. Isolate pathogenicity was confirmed on honeysuckle and further evaluated in susceptible crops. Tomato, cotton, soybean, and cucumber were inoculated with colonized agar blocks in detached leaf and live plant assays. Tomato and cotton developed disease symptoms in both assays, while the soybean and cucumber varieties tested were not susceptible to the pathogen. Other weedy hosts of C. cassiicola have been documented, but no isolates collected from honeysuckle have been assessed previously for pathogenicity to crops. Honeysuckle populations are common in cotton producing regions and may facilitate the movement or persistence of C. cassiicola causing target spot.