Initial seedling growth rates in a semi-dwarf spring wheat collection

A relationship was observed between seedling growth rate and seedling emergence under conditions of soil capping. Coleoptile and root growth rates were strongly influenced by the origin of the seed sample and the genotype involved, whereas genotype × environment interactions were small and not significant. A test-cross analysis revealed the presence of strong epistatic effects for the characters coleoptile growth rate and coleoptile diameter. Both additive and dominance variation contributed strongly to the total genetic variation for coleoptile growth rate, while the - dominance appeared to be ambidirectional. Genetic variation for coleoptile diameter was found to be predominantly additive. Whereas both traits were expected to respond well to selection, no consistent correlations with simple plant characteristics could be established, a situation that may limit the utilization of the observed genetic differences through indirect selection.