Author
![]() |
CAMARA, MARCOS |
![]() |
Oneill, Nichole |
![]() |
Van Berkum, Peter |
Submitted to: BARC Poster Day
Publication Type: Abstract Only Publication Acceptance Date: 3/1/2001 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: The phylogenetic relationships among 43 isolates representing 16 species of Stemphylium were inferred from ITS and glyceraldehyde-3-phosphate dehydrogenase (gpd) gene sequence data. The results generally agree with morphological species concepts. Species that are primarily pathogenic to alfalfa are resolved into two separate groups. Stemphylium botryosum and two isolates with morphological characters similar to S. globuliferum had identical sequences at both loci. These two loci in S. vesicarium, S. alfalfae and S. herbarum are nearly identical but differ from S. botryosum. Stemphylium lycopersici and S. xanthosomatis differ by a single nucleotide in the gpd region and have identical ITS sequences. Morphological and developmental characters such as sizes and shapes of the conidia, conidiophores and ascospores and the size and time of maturation of pseudothecia are useful for determining species. However, other morphological characters such as septum development and small variations in conidium wall ornamentation are not as useful. Contact person: Nichole O'Neill USDA, ARS Molecular Plant Pathology Laboratory |