Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/23/2006
Publication Date: 7/23/2006
Citation: Friesen, T.L., Lai, Z., Liu, Z., Faris, J.D., Steffenson, B.J. 2006. Genetic mapping of pyrenophora teres avirulence genes. In: Proceedings of the 3rd International Workshop on Barley Leaf Blight. July 23-27, 2005, Edmonton, Canada. p. Interpretive Summary: A Pyrenophora teres f. teres population was used to evaluate the genetics of avirulence associated with barley lines Canadian Lake Shore (CLS), Tifang, and Prato. Parental isoltes used showed different reactions on the three barley lines and therefore were hypothesized to contain different genes associated with avirulence. A molecular map was constructed to identify genes associated with disease. A single gene (AvrHar) conferred avirulence to Tifang and CLS and accounted for 84 and 85% of the disease, respectively. Avirulence on Prato was conferred by two genes accounting for 25% (AvrPra1) and 32% (AvrPra2) of the disease. AvrPra2 was at the same chromosomal location as AvrHar, but was contributed by the opposite parent. This work provides the foundation for the cloning and characterization of these genes.
Technical Abstract: A Pyrenophora teres f. teres cross between isolates 0-1 and 15A was used to evaluate the genetics of avirulence associated with barley lines Canadian Lake Shore (CLS), Tifang, and Prato. 15A is avirulent on Tifang and CLS, but virulent on Prato. Conversely, 0-1 is avirulent on Prato, but virulent on Tifang and CLS. Avirulence conferred by 15A on Tifang and CLS segregated 1:1, whereas avirulence on Prato segregated 3:1. A linkage map was constructed to identify QTLs associated with the disease phenotype. A single locus derived from 15A (AvrHar) conferred avirulence to Tifang and CLS. Avirulence on Prato was conferred by 0-1 at two redundant loci accounting for 25% (AvrPra1) and 32% (AvrPra2) of the disease variation. AvrPra2 co-segregated with AvrHar, but was contributed by 0-1. Map based cloning has been initiated and several clones have been identified from BAC libraries developed from 15A and 0-1. Isolation and characterization of the Avr genes and their products will lead to studies to decipher their mode of action and provide better understanding of interactions that occur within the barley-P. teres pathosystyem.