Ali, Shawkat , Bakkeren, Guus .
Marker-based approaches for the cloning of the Avr6 gene in Ustilago hordei..
The fungal pathogen Ustilago hordei causes covered smut on barley and oats. Genetic studies revealed the presence of six avirulence (Avr) genes in the pathogen and corresponding resistant genes in barley cultivars which confer gene-for-gene resistance. Molecular characterization of these Avr genes is important in order to understand the delicate interaction between the pathogen and its host. A population of U. hordei, segregating for three unlinked dominant Avr genes has been generated in our laboratory from a cross between a virulent strain Uh4854-10 (MAT-2, avr1, avr2, avr6) and an avirulent strain Uh4857-4 (MAT-1, Avr1, Avr2, Avr6). Pools of progeny bulked for Avr6 and avr6 respectively, were used to identify linked Simple Sequence Repeat (SSR) and Amplified Fragment Length Polymorphism (AFLP) markers. 115 SSR primer pairs designed using the genome sequence from the closely related fungus U. maydis, were tested. Ten pairs revealed polymorphisms in parents and pools with tentative linkage to Avr6. Subsequent analysis of 48 individual progeny (25 Avr6 and 23 avr6) failed to confirm linkage. An AFLP approach, successful in mapping and isolating Avr1 and in fingerprinting other small grain-infecting Ustilago species in our laboratory, is currently being used. Several AFLP markers potentially linked to Avr6/avr6 have been identified in the pools and segregation amongst individual progeny is being tested.
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1 - University of British Columbia, Botany Department, 3529-6270 University Boulevard, Vancouver, British Columbia, V6T 1Z4, Canada
2 - Agriculture & Agri-Food Canada, Pacific Agri-Food Research Centre, Summerland, BC, V0H 1Z0, Canada
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM