Agronomic and quality evaluation of common wheat near-isogenic lines carrying the leaf rust resistance gene Lr47

Wheat leaf rust (Puccinia triticina) causes significant yield losses in wheat production worldwide. Genetic resistance is a cost-effective way to reduce these losses. Among the known leaf rust (Lr) resistance genes, nearly half are from alien sources. However, their deployment into wheat (Triticum aestivum L.) cultivars has been limited, likely because of fear of potential negative effects of linked alien genes. We report here the effects of the Lr47 introgression from Triticum speltoides on agronomic and quality traits in common wheat. Five pairs of hard red spring near-isogenic lines were tested in replicated field trials from 2002 to 2004. The presence of the Lr47 introgression was associated with an overall 3.8% reduction in grain yield (220 kg ha(-1)), but it varied significantly across genotypes and environments. The Lr47 introgression also affected several quality parameters. Lines with the alien Lr47 segment showed consistent increases in grain and flour protein concentration (4 to 5 g kg(-1), P < 0.01) but also highly significant decreases in flour yield (21.8 g kg(-1), P < 0.001) and increases in flour ash (0.14 g kg(-1), P < 0.01). This information will help wheat breeders make informed decisions about the deployment of Lr47 in their breeding programs. An additional round of homeologous recombination will be necessary to determine if the detrimental effects on milling parameters are pleiotropic effects of Lr47 or the result of linked genes.