A diagnostic guide of Volutella blight affecting Buxaceae

Authors: YANG, XIAO - US Department Of Agriculture (USDA); CASTROAGUDIN, VANINA - US Department Of Agriculture (USDA); DAUGHTREY, MARGERY - Cornell University; LOYD, ANDREW - Bartlett Tree Service; Weiland, Gerald - Jerry; Shishkoff, Nina; BAYSAL-GUREL, FULYA - Tennessee State University; SANTAMARIA, LUISA - Oregon State University; Salgado-Salazar, Catalina; LAMONDIA, JAMES - Connecticut Agricultural Experiment Station; Crouch, Jo Anne; Luster, Douglas - Doug

Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2021
Publication Date: 7/14/2021
Citation: Yang, X., Chastrogudin, V.L., Daughtrey, M.L., Loyd, A., Weiland, G.E., Shishkoff, N., Baysal-Gurel, F., Santamaria, L., Salgado-Salazar, C., Lamondia, J., Crouch, J., Luster, D.G. 2021. A diagnostic guide of Volutella blight affecting Buxaceae. Plant Health Progress. 22:578-590. https://doi.org/10.1094/PHP-02-21-0052-DG.
DOI: https://doi.org/10.1094/PHP-02-21-0052-DG

Interpretive Summary: Volutella blight is a common disease of species in the plant family that includes boxwood, pachysandra and sarcococca. Despite the fact that the disease has been consistently found over the past 150 years in all continents except for Antarctica, there are numerous complications in identifying the signs and symptoms of its causal pathogens. In this diagnostic guide, we provide a comprehensive review of the three fungal pathogens that cause Volutella blight disease. New data describing structures and forms of the pathogens are also provided in this guide. Furthermore, a detailed comparison of diagnostic traits of three major fungal diseases on boxwood, namely Volutella blight, boxwood blight, and boxwood dieback, is included. This guide aims to provide integrated information to aid the diagnosis of Volutella blight and facilitate new research to advance our knowledge of this old, but under-studied disease.

Technical Abstract: Volutella blight is a common disease of species in the plant family Buxaceae, specifically boxwood, pachysandra and sarcococca. Despite the fact that the disease has been consistently found over the past 150 years in all continents except for Antarctica, there are numerous complications in its etiology, signs and symptoms, and taxonomy, morphology, isolation, and preservation methods of its causal pathogens. For example, one of the two pathogens causing Volutella blight on boxwood, Pseudonectria buxi, has gone by at least 25 names including Volutella buxi and P. rousseliana, since its original description in 1815. The other pathogen on boxwood, P. foliicola, was not described until 2015. Although Coccinonectria pachysandricola, previously named as V. pachysandricola, has been known as a pathogen of pachysandra since 1944, it was only recently demonstrated in 2019 that the same pathogen can infect sarcococca. In this diagnostic guide, we provide a comprehensive review on the taxonomy, symptoms, host range, distribution, isolation, identification, storage, and pathogenicity of the Volutella blight disease and these three fungal pathogens. New data, such as previously unreported perithecial morphological characters of P. buxi and a unique sporodochia-forming pattern of C. pachysandricola, are also provided in this guide. Furthermore, a detailed comparison of diagnostic traits of three major fungal diseases on boxwood, namely Volutella blight, boxwood blight, and boxwood dieback, is included. This guide aims to provide integrated information to aid the diagnosis of Volutella blight and facilitate new research to advance our knowledge of this old, but under-studied disease.