Understanding the genetic control of lodging-associated plant characters in winter wheat (Triticum aestivum L.)

A genetic analysis of plant characters associated with lodging resistance, yield and other agronomic traits was made on two doubled haploid winter wheat populations grown at two UK locations in the 2004/2005, 2005/2006 and 2006/2007 seasons. Wide genetic variation was found for traits that affect lodging, including plant height, components of stem strength (stem diameter, wall width and material strength), components of anchorage strength (spread and depth of the root plate), ear area and shoot number per plant. Heritabilities were estimated for each of the key lodging traits, with plant height having the highest heritability and anchorage traits the lowest values. Six quantitative trait loci (QTL) controlling plant height had individual height effects (2 x the additive effect) of 3-9 cm and taken together, could potentially increase plant height by up to 34 cm. Three of the height QTL were also associated with greater yield or greater thousand grain weight, and three were associated with components of stem strength or anchorage strength. QTL were also identified for each of the measured lodging traits, which were unrelated to height. Individual QTL with the largest estimated effects on lodging resistance were for height, stem diameter, stem material strength, stem failure moment, root plate spread and root plate depth. Diagnostic genetic markers for the most important QTL regions are now required to enable breeders to efficiently combine multiple traits together in a single variety that will increase lodging resistance and yield simultaneously.