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Title: SYSTEMATICS OF PARAPHAEOSPHAERIA: A MOLECULAR AND MORPHOLOGICAL APPROACH

Author
item CAMARA, MARCOS - PENN STATE UNIVERISTY
item PALM, MARY - APHIS/USDA
item STEWARD, ELWIN - PENN STATE UNIVERSITY
item Van Berkum, Peter

Submitted to: Mycologia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/21/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary: The genus Paraphaeosphaeria are fungi that are plant pathogens, that under the correct environmental conditions may affect agricultural production. Classification and identification of the species within this genus is not clear. This problem has relevance to identification of disease and identification of infective agents on imported plant material. Therefore, we used a molecular approach to evaluate current classification of species within Paraphaeosphaeria. We observed that the members of this genus are highly diverse and constitute at least three separate genera. The morphological characters that were used were insufficiently informative to distinguish the species. We found other reliable morphological characters that permitted prediction of the genetic relationships within the genera. This information is important for scientists and quarantine workers attempting to stop the import of potential plant pathogens.

Technical Abstract: The genus Paraphaeosphaeria (Loculoascomyetes) was described as a segregate of Leptosphaeria for species producing ascospores with rounded ends, a submedian primary septum, an inflated cell above the primary septum, and a Coniothyrium anamorph. This study evaluated the taxonomic value of the morphological characters, host range, ecology, and anamorphs in relation to DNA sequence data in order to determine the relationship between species described in Paraphaeosphaeria. Nine species were characterized morphologically and the ITS and 18S regions of the rDNA were sequenced and a phylogeny was inferred. Morphological studies and results of the sequence analyses provide strong support for polyphyly of this genus. Based on these analyses, the concept of Paraphaeosphaeria should be narrowed to reflect a monophyletic generic concept. Characters such as spore septation and method of conidiogenesis were found to predict relatedness.