Host genetic analysis by using Puccinia recondita tritici induced mutants for increased virulence
1993
Saione, H.A. (Instituto Nacional de Tecnologia Agropecuaria, Castelar (Argentina). Inst. de Genetica) | Favret, E.A. | Franzone, P.M. | Sacco, F.
Monogenic lines derived by recombination from Buck Manantial wheat, a cultivar which has durable resistance, were used as hosts to detect Puccinia recondita tritici induced mutants for increased virulence. After treatments with ethyl methane sulphonate on clone 66 of P. recondita 9 types of mutants were obtained at approximate frequencies of 1 x 10(-4) and host lines were grouped in 6 classes. No increase virulence was obtained against B. Manantial after 2 cycles of treatments, but different combinations of virulences were observed in monogenic lines derived from it. Simultaneity of occurrence of some mutational events suggests complexity of virulence genes in the pathogen. At least 4 genes for imcompatibility are present in B. Manantial when confronted with clone 66 and 4 to 7 mutational points are recognized in the pathogen. The specific relationships tending to equate the number of genes in both organisms would not be a general rule. Durable resistance can be explained by a combination of several specific disease reaction genes for which the pathogen population has not been able to accumulate all the corresponding alleles for virulence
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