Genetic bases of wheat grains natural dehiscence: an artificial estimate involving the glume and lemma vigor character

Abstract

Grain yield losses from natural shattering require the development of shatter resistant genotypes, and breeding methods depend on the type of variability and genetic conditioning the trait under study. Shatter tolerance was measured in wheat (Triticum aestivum L.) as the force required to free a glume and lemma from the raquis. Measurements were made on single, random plants of six generations (P₁, P₃, F₁, F₂, RC₁F₁ and RC₂F₁) from crosses among four parental lines. All populations were grown at the Experimental Agronomic Station/UFRGS, Guaíba, RS, in 1978. High genetic variability was detected. Additive for glume and lemma vigor susceptibility as well as epistatic effects separating the parents were observed. In general, the results suggest that the inheritance of shattering resistance is not too complex and the expression of gene effects appears not to be sensitive to environmental conditions. However, because glume and lemma vigor is recessive and because genes with large effects were present in these crosses, direct selection for shattering resistance in early generations should be effective.