Evaluation of genomic approaches for marker-based improvement of lodging tolerance in triticale.

Lodging tolerance is an important agronomic trait as it can have a severe negative impact on grain yield and quality. Here, we used a large mapping population of 647 doubled haploid triticale lines derived from four families to dissect the genetic architecture underlying lodging tolerance and to assess different approaches for a genomics-based improvement of the trait. The plants were evaluated for lodging in two environments and genotyped with 1710 genomewide DArT markers. We observed a large genotypic variation for lodging and transgressive segregation in all families. Employing two complementary QTL mapping approaches, we identified both main effect and epistatic QTL. Using cross-validation, we showed that the proportion of genotypic variance explained by the detected QTL is low, thus limiting the efficiency of marker-assisted selection to improve this trait. By contrast, the cross-validated predictive ability of genomic prediction was approximately twice as high as that of the QTL-based selection approaches. In conclusion, our results show that lodging tolerance is a complex trait that can be improved by classical breeding but also assisted by marker-based approaches. [ABSTRACT FROM AUTHOR]