VIEW ARTICLE

Heritability of Field Resistance to the Oat Crown Rust Fungus. M. D. Simons, Research Plant Pathologist, Agricultural Research Service, U.S. Department of Agriculture, Ames, Iowa 50010; Phytopathology 65:324-328. Accepted for publication 8 October 1974. DOI: 10.1094/Phyto-65-324.

Four unadapted strains of oats (Avena sativa) with field resistance to crown rust (Puccinia coronata) were crossed with an adapted, but susceptible, cultivar. Lines from these crosses previously selected for adapted plant type were tested in two generations for resistance to crown rust, as measured by relative reduction in yield and kernel weight caused by crown rust infection. Lines from each of the four crosses showed the continuous variation from susceptibility to resistance characteristic of polygenic inheritance. Heritability values estimated from components of variance for resistance, measured in terms of yield reduction, ranged from 46 to 86%; and, in terms of reduction in kernel weight, from 65 to 92%. The relationship of yield to resistance in the absence of rust was generally negative, with correlation coefficients ranging from 0 to –0.69. None of the lines tested combined maximum yield with maximum resistance.