Submitted to: Fungal Genetics Newsletter
Publication Type: Abstract Only
Publication Acceptance Date: January 1, 2001
Publication Date: March 13, 2001
Citation: SZABO, L.J., BALMUTH, A.L. PROGRESS TOWARDS CLONING AVIRULENCE GENES IN THE WHEAT STEM RUST FUNGUS, PUCCINIA GRAMINIS. FUNGAL GENETICS NEWSLETTER. 2001. v. 49. p. S287. Technical Abstract: Puccinia graminis is a heteroecious rust fungus, with uredinial (asexual) and telial stages on cereal and forage grass species and the pycnial and aecial stages on members of the barberry family. Genetics has demonstrated that infection of wheat by P. graminis f.sp. tritici follows a gene-for-gene interaction involving resistance genes in the host and avirulence genes in the rust pathogen. In order to better understand this interaction, we have undertaken the cloning of several avirulence genes from P. graminis f.sp. tritici. A mapping population of P. graminis has been developed in which eight single dominant avirulence genes are segregating (Zambino et.al., 2000). DNA markers (AFLPs and RAPDs) have been used to construct a partial genetic map in which these avirulence genes have been mapped to seven linkage groups. Avirulence genes AvrT8a and AvrT9a have been selected for developing physical maps. Eight AFLP and one RAPD markers linked to these avirulence genes have been cloned and segregation of locus-specific PCR primers have been confirmed. In addition, six other AFLP markers have been cloned and development of locus-specific PCR primers are being developed and positonally cloned.