Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/14/1996
Publication Date: N/A
Technical Abstract: Pyricularia species are isolated from many monocot species. Several researchers have attempted to group these isolates by examining morphology, host range, sexual compatibility, etc. Although at least five subgroups (isolates from mioga, crabgrass, Manchurian wild rice, finger millet, and rice) could be clearly discriminated, there remained many isolates whose grouping was ambiguous. MAGGY is a retrotransposon found in the genomic DNA of Pyricularia species. It is 5.6 kb in size and flanked by 253 bp LTRs (Long Terminal Repeats). Its internal region shows homology at the peptide level to reverse transcriptases of the Gypsy class of retrotransposons. In the present study, the distribution of MAGGY in Pyricularia isolates from various hosts was investigated to reveal their phylogenetical relationships. Genomic DNA was extracted from Pyricularia isolates from various hosts, digested with PstI, and hybridized with a MAGGY probe. MAGGY was present in a high copy number (at least 35-45 copies) in isolates form rice, foxtail millet (Setaria italica), and green bristlegras (S. viridis), but absent in those from wheat, finger millet, goosegrass, crabgrass, Digitaria horizontalis, and mioga. These results suggest that isolates from rice are phylogenetically close to those from Setaria species. The present results also suggest that MAGGY will be a good probe for fingerprinting of rice and Setaria isolates. Genomic DNA of isolates from millet (Panicum miliaceum) contained an unknown element, which hybridized with MAGGY but had different restriction sites. Cloning of this element is under way.