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United States Department of Agriculture

Agricultural Research Service

Title: Molecular Phylogenetics As a Tool for the Identification of Phytopathogenicisolates of Fusarium

Authors
item O`donnell, Kerry
item Cigelnik, Elizabeth

Submitted to: National American Phytopathology Meetings
Publication Type: Abstract Only
Publication Acceptance Date: July 31, 1996
Publication Date: N/A

Technical Abstract: A phylogenetically-based classification of Fusarium is being inferred from DNA sequence data obtained from multiple unlinked loci. The ever expanding database currently consists of about 3 million base pairs of DNA sequence data from over 1500 strains. Typically PCR products are sequenced directly but heterogenous DNA templates amplified from polymorphic loci are cloned to obtain readable sequence data. Maximum parsimony analyses are being conducted to assess the monophyly and sister relations of Fusarium and its teleomorphs (Gibberella, Nectria, and Neocosmospora) and the subgeneric species groupings called sections. DNA sequences contain a wealth of derived characters that are being used to diagnose phylogenetic species (PSC) sensu Nixon and Wheeler (1990). The PSC is concordant with the biological species concept (BSC) to the extent that both have been applied within Fusarium. Preliminary application of the PSC indicates that many morphological species are artificial. Selected morphospecies will be used to critique taxonomies developed by "splitters" and "lumpers."

Last Modified: 10/24/2014
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