Author
 |
Aime, Mary |
|
Submitted to: Bean Improvement Cooperative Meeting Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 11/23/2005 Publication Date: 1/21/2006 Citation: Aime, M.C. 2006. Systematics and molecular variability of bean rusts [abstract]. Annual Report of the Bean Improvement Cooperative 49:45-46. Interpretive Summary: Technical Abstract: The systematics and genetic variability of rusts on Fabaceae are examined within a molecular phylogenetic context. Sequence analysis of nuclear ribosomal large subunit DNA (LSU) suggests that rusts on Fabaceae may have as few as three independent origins within the Uredinales. Rusts pathogenic on subfamily Papilionoideae are confined to two lineages, one within the Pucciniaceae, and the other within the Phakopsoraceae p.p. Rusts occurring on Phaseolus spp. form part of the crown clade in both lineages. Analysis of nuclear ribosomal internal transcribed spacer region DNA (ITS) resolves three species of Uromyces (Pucciniaceae lineage) found on P. vulgaris, but these do not correspond to prior morphology-based reports. Within the species U. appendiculatus a protein gene encoding the elongation factor 1-alpha (EF1-') was found to be hypervariable. Analyses of EF1-' haplotype data show two well-defined gene pools for this rust that correspond to the Andean and Mesoamerican gene pools of its host. Dikaryotic data, however, show the presence of a third, intermediate, genotype that may be the result of hybridization events between the two parental gene pools. There is no evidence for sexual outcrossing within the Andean gene pool, nor between the Andean and Mesoamerican. A rapid diagnostic test has been developed to quickly genotype isolates of U. appendiculatus into one of these three main genotypes. |
