VIEW ARTICLE

Genetics

Inheritance of Leaf and Head Resistance of Winter Wheat to Septoria nodorum in a Diallel Cross. P. M. Fried, Swiss Federal Research Station for Agronomy, 8046 Zurich, Switzerland; E. Meister, Swiss Federal Research Station for Agronomy, 8046 Zurich, Switzerland. Phytopathology 77:1371-1375. Accepted for publication 25 February 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/Phyto-77-1371.

A diallel analysis of four parents of similar heading date and plant height but differing in resistance to Septoria nodorum on leaves and heads (as estimated by area under the disease progress curves) showed that the genetic variation is mainly additive. Statistical tests for the nonadditive variation indicated that dominance for susceptibility was significant, but that interaction between nonallelic genes was not. No cytoplasmic effects could be detected. Heritability estimates based on parents and F₁’s varied between 0.48 and 0.68. Estimates based on the standard-unit method were 0.30 and 0.26 for flag leaves and heads, respectively. Evidence for independent segregation of the genes controlling head and leaf resistance could be found by correlation analysis between F₂’s and F₃’s.