Genetic diversity of Mycosphaerella graminicola, the Septoria tritici blotch pathogen of wheat in Kansas

• Published in: Phytopathology Vol. 94; no. 6
• Main Authors: Kabbage, M, Zeller, KA, Hulbert, SH, Bockus, W W
• Format: Journal Article
• Language: English
• Published: 01-06-2004
• Subjects: Mycosphaerella graminicola; USA, Kansas
• ISSN: 0031-949X

The genetic diversity of natural populations of Mycosphaerella graminicola has not been investigated in the central Great Plains of the USA, one of the most important wheat producing areas in the world. Studies of this fungus from other regions show regular recombination and significant gene flow. This study, in addition to investigating the statewide genetic diversity of this pathogen, focused on comparing fall versus spring populations. Genetic diversity was investigated at three levels, the entire state, an entire field, and micro-plot ( approximately 1 m2). For statewide diversity, isolates were obtained from 60 fields throughout Kansas. Micro-plot and field populations were examined at four different locations and at least 50 isolates were obtained from each site at each sample date. Pycnidiospores were isolated from single pycnidia on leaf lesions and grown on YG medium for DNA extraction. AFLP profiles of all isolates were generated to study each of the populations. Initial data show high diversity among Kansas isolates collected in the fall. This suggests that the sexual stage is important for initial infections. AFLP profiles from isolates obtained in the spring will be compared with those from the fall.