Abstract
Heterobasidion annosum sensu lato is a species complex of pathogenic white-rot wood decay fungi which cause root and butt rot in conifer and hardwood species across the Northern hemisphere. Annual losses to forest managers are valued in the billions of dollars, due to tree mortality, reduction in timber yield, and wood decay. In North America, H. irregulare and H. occidentale have a partially overlapping host and geographic range, cause similar disease symptoms and produce similar fruiting bodies, making discrimination between the two of them often difficult. We developed two sets of primers that bind specifically to conserved, but species-specific portions of glyceraldehyde 3-phosphate dehydrogenase and elongation factor 1α alleles. The method is sensitive enough to detect either species from infected wood. Analysis of North American isolates has further clarified the distribution of both species on this continent, including the detection of H. irregulare for the first time on ponderosa pine (Pinus ponderosa) and eastern white pine (Pinus strobus) in British Columbia. This method has the potential to be a valuable tool for the detection of the pathogen in exported/imported wood products, as well as for the further identification and assessment of the distribution of North American Heterobasidion species.
Highlights
Heterobasidion annosum (Fr.) Bref. sensu lato (s.l.) is a significant forest pathogen that causes root and butt rot primarily in conifers across the Northern Hemisphere
Protocol described in this paper has allowed us to diagnose both North American species directly from infected woody tissue, saving time and costs compared to culture-based methods
The small product size allowed for the testing of preserved herbarium collections, where DNA integrity is low and conventional PCR
Summary
Heterobasidion annosum (Fr.) Bref. sensu lato (s.l.) is a significant forest pathogen that causes root and butt rot primarily in conifers across the Northern Hemisphere. Sensu lato (s.l.) is a significant forest pathogen that causes root and butt rot primarily in conifers across the Northern Hemisphere. The tree disease caused by Heterobasidion spp. is referred to as Annosus root and butt rot, and the mortality it causes in old growth forests is regarded as an important driver of forest turnover and natural biodiversity. Pathogens 2019, 8, 156 the most important disease of conifers worldwide. The genus Heterobasidion has been recently split into three genetically distinct clusters (H. annosum, H. insulare and H. araucariae) containing a total of 12 species [4] and a newly described hybrid taxon [5]. The H. annosum cluster includes two North American partially intersterile species, namely H. irregulare and H. occidentale [6], and a newly described hybrid taxon genetically distinct from the other two [5]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have