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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Mycology and Nematology Genetic Diversity and Biology Laboratory » Research » Publications at this Location » Publication #349551

Research Project: Enhancing Plant Protection through Fungal Systematics

Location: Mycology and Nematology Genetic Diversity and Biology Laboratory

Title: Boxwood blight: an ongoing threat to ornamental and native boxwood

item LEBLANC, NICHOLAS - Orise Fellow
item Crouch, Jo Anne

Submitted to: Applied Microbiology and Biotechnology
Publication Type: Review Article
Publication Acceptance Date: 3/13/2018
Publication Date: 4/2/2018
Citation: Leblanc, N., Salgado-Salazar, C., Crouch, J.A. 2018. Boxwood blight: an ongoing threat to ornamental and native boxwood. Applied Microbiology and Biotechnology. 102(10):4371-4380.

Interpretive Summary: Boxwood blight is a deadly fungal disease of boxwood and related plants such as pachysandra and sarcococca. The disease was first discovered from England and New Zealand at the end of the 20th century, then moved rapidly across Europe in a matter of years, and most recently showed up the United States, Canada and Asia in 2011. Prior to 1998, the fungus had never been seen before, and scientists in affected countries rapidly mobilized to find ways to protect endangered plants and eradicate the fungal pathogen. This article summarizes the current knowledge of boxwood blight, with particular emphasis on the genetics and biology of the pathogen. These findings are significant because they provide information about how environmental conditions could be manipulated to reduce the impact of boxwood blight. This article will provide a useful, centralized source of the latest research findings on boxwood blight disease for scientists, extension personnel, regulatory agencies, and boxwood growers in the United States and worldwide.

Technical Abstract: Boxwood blight is an emerging disease of ornamental and native boxwood plants in the family Buxaceae. First documented in the 1990s at a single location in England, the disease is now reported throughout Europe, Asia, New Zealand, and North America. To address the growing concern over boxwood blight, ongoing research has focused on multiple biological and genetic aspects of the causal pathogens and susceptible host plants. Characterization of genetic variation among the Calonectria fungi that cause boxwood blight has shown two unique sister species with different geographic distributions cause the disease. Studies of the pathogen lifecycle show the formation of long-lived survival structures and host infection that is dependent on inoculum density, temperature and humidity. Host range investigations show high levels of susceptibility among boxwood as well as the potential for other plants in the family Buxaceae to serve as alternate hosts. Multiple DNA-based diagnostic assays are available, ranging from probe-based quantitative PCR assays to the use of comparative genomics to develop robust diagnostic markers or provide whole genome-scale identifications. Though many questions remain, the research that continues to address boxwood blight demonstrates the importance of applying a multidisciplinary approach to understand and control emerging plant diseases.