Quantitative resistance to oat crown rust is being praised in breeding programs in search of more durable resistance because it exerts less selection pressure for virulence on the pathogenic population than does qualitative resistance. This type of resistance results from the combination of components such as: long latency period, short period of infection, low infection efficiency and pustules of reduced length. However, in this pathosystem the individual role of each component in disease development is not known, and nor are the number of genes that control these traits. This work aimed to characterize some aspects of the inheritance of quantitative resistance to crown rust in 83 F6:10 white oat recombinant lines from the UFRGS 7 (susceptible) x UFRGS 910906 (quantitative resistance) cross. The results indicate that this resistance is of a polygenic nature; it seems to be governed by several genes of small effect, and its expression results from the combined effect of more than one component.
Puccinia coronata f. sp. avenae; Avena sativa; components of resistance; minor genes
