Phenotypic and genetic characterization of partial resistance to crown rust in Avena sativa L.
Felipe Zambonato, Luiz Carlos Federizzi, Marcelo Teixeira Pacheco, Marcio Pais de Arruda and Jose Antonio Martinelli
Abstract – Crown rust is a major oat disease. Partial resistance is a promising option for disease control for being potentially more durable than complete resistance. The objective of this study was to investigate the inheritance of partial resistance to crown rust in oat populations that were derived from a cross between cultivar URS 21 (partially resistant) and URS 22 (susceptible). In 2010, the six basic generations (P1, P2, F1, F2, BC1, and BC2) were sown in the field, and resistance to crown rust was assessed using the area under the disease progress curve, normalized and corrected for each individual plant. The inheritance of the trait partial resistance was oligogenic, indicating the presence of genes with both major and minor phenotypic effects. Additive and dominance effects were important to determine the partial resistance and the heritability estimates were high, indicating the possibility of selection for resistance
in early generations.