Observations on the biology of Ophiodothella angustissima

Authors: HANLIN, RICHARD - University Of Georgia; OWENS, JIMMY - University Of Georgia; ICARD, ALAN - University Of Georgia; Glenn, Anthony - Tony; GONZALEZ, MARIA - Universidad Nacianal Autonoma De Mexico

Submitted to: North American Fungi
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/24/2018
Publication Date: 7/29/2018
Citation: Hanlin, R.T., Owens, J.O., Icard, A.H., Glenn, A.E., Gonzalez, M.C. 2018. Observations on the biology of Ophiodothella angustissima. North American Fungi. 13(2):1-9.

Interpretive Summary: This article presents a summary of the natural history and host interactions of the fungal pathogen Ophiodothella augustissima that causes a leafspot disease on Vaccinium arboreum, a shrub native to the southern United States and commonly known as sparkleberry. In autumn, diseased leaves fall to the ground where the fungus is able to overwinter. The fungus in the leaves matures with the onset of warm temperatures and spring rains, conditions that also favor the development of new leaves on the host. The mature fungus ejects spores upward onto young host leaves, which they infect. These new infections grow and produce reproductive structures and spores that spread the disease throughout the plant during the summer. The timing of these events is determined by weather conditions, especially rainfall. As infected leaves drop to the ground in autumn, they remain beneath the shrubs, where they overwinter, ready to begin the cycle again the following spring. The disease can be managed by removal of the dropped leaves, which will disrupt the life cycle of the fungus and reduce the infection of sparkleberry leaves the following spring.

Technical Abstract: Ophiodothella augustissima causes a leafspot disease on shrubs of Vaccinium arboreum. In autumn, diseased leaves bearing lesions fall to the ground where they overwinter. These lesions contain perithecial initials that mature with the advent of warm temperatures and spring rains, conditions that also favor the development of new leaves on the host. Mature perithecia contain asci with ascospores that are forcibly ejected upward onto young host leaves, which they infect. These new lesions grow and produce an acervular stage that forms numerous conidia that spread the disease throughout the plant during the summer. The timing of these events is determined by weather conditions, especially rainfall. As infected leaves dehisce in autumn, they remain beneath the shrubs, where they overwinter, ready to begin the cycle again the following spring.