Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: March 30, 2000
Publication Date: N/A
Technical Abstract: The DNA fingerprint probe pSTL70 has been used to characterize thousands of isolates of the septoria tritici blotch pathogen, Mycosphaerella graminicola, yet the genetic basis for the fingerprints have not been determined. To test whether pSTL70 is a transposable element, the original clone and three others identified by hybridization were sequenced. The analyses revealed a long direct repeat near the 3' end of a putative reverse transcriptase (RT) gene. Southern analysis with the RT sequence as a probe duplicated the original DNA fingerprint. Analysis of 60 progeny from a cross between two isolates of M. graminicola identified new bands indicating movement during meiosis. Analysis of 20, 10-generation single-spore lines (200 asexual generations) identified gains and losses of bands in four of the 20 lines. These changes were confirmed by analysis of five more isolates from each of the four variable lines. Thus, the DNA fingerprint probe pSTL70 identifies a transposable element in M. graminicola that is active during both sexual and asexual reproduction.