VIEW ARTICLE

Modification of Tolerance of Oats to Crown Rust by Mutation Induced with Ethyl Methanesulfonate. M. D. Simons, Research Plant Pathologist, Plant Science Research Division, ARS, USDA, Ames, Iowa 50010; Phytopathology 61:1064-1067. Accepted for publication 2 April 1971. DOI: 10.1094/Phyto-61-1064.

Oat (Avena sativa) kernels were treated with ethyl methanesulfonate (EMS), and the crown rust (Puccinia coronata var. avenae) tolerance (as measured by yield and kernel weight) of lines derived from this material was compared with untreated controls. Variance of the tolerance of treated lines was significantly greater than the variance of the control. Heritability of tolerance of treated lines, estimated from analysis of 2 years’ data, was relatively high. The over-all mean tolerance of treated lines was significantly lower than that of the control and, individually, many treated lines were less tolerant than the control. A few lines, however, were superior to the control in both yield and kernel weight response to infection. In the absence of crown rust, however, all “superior” lines yielded significantly less than the control.