Gene action and linkage of avirulence genes to DNA makers in the rust fungus Puccinia graminis
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Phytopathology. 90(8): 819-826. (2000)
Two strains of the wheat stem rust fungus, Puccinia graminis f. sp. tritici, were crossed on barberry, and a single F1 progeny strain was seifed. The parents, F1 and 81 F2 progeny were examined for virulence phenotypes on wheat differential cultivars carrying stem rust resistance (Sr) genes. For eight Sr differentials phenotypic ratios are suggestive of single dominate avirulence genes AvrT8a, AveT9a, AvrT10, AvrT21, AvrT28, AvrT30, and AvrTU. Avirulence on the Sr. (Sr 'fleck') differential showed phenotypic ratios of approximately 15:1, indicating epistatic interaction of two genes dominant for avirulence. Avirulence on Sr9d favored a 3:13 over a 1:3 ratio, possibly indicating two segregating geues-one dominant for avirulence and one dominant for avirulence inhibition. Linkage analysis of eight single dominant avirulence genes and 970 DNA markers indentified DNA markers linked to each of these avirulence genes. The closest linkage between AvrT genes and DNA markers were between AvrT6 and the random amplified polymorphic DNA marker cr134-155 (6 centimorgans [cM]) AvrT8a and the amplified fragment lenght polymorphism marker cAC/mCT-197 (6 cM) and between AvrT9a and the amlified fragment lenght polymorphism marker cAC/mCT-184 (6 cM). AvrT10 and AvrTU are linked at distance of 9 cM.
KeywordsAFLP; avirulence gene nomenclsture; molecular map; RAPD; Triticum aestivum; T. durum
Zambino, P. J.; Kubelik, A. R.; Szabo, L. J. 2000. Gene action and linkage of avirulence genes to DNA makers in the rust fungus Puccinia graminis. Phytopathology. 90(8): 819-826. (2000) https://doi.org/10.1094/phyto.2000.90.8.819.