Changes in allele frequencies in landraces, old and modern barley cultivars of marker loci close to QTL for grain yield under high and low input conditions

Abstract

Changes in alleles frequencies of marker loci linked to yield quantitative trait loci (QTL) were studied in 188 barley entries (landraces, old and modern cultivars) grown in six trials representing low and high yielding conditions in Spain (2004) and Syria (2004Syria ( , 2005. A genome wise association analysis was performed per trial, using 811 DArT Ò markers of known map position. At the first stage of analysis, spatially adjusted genotypic means were created per trial by fitting mixed models. At the second stage, single QTL models were fitted with correction for population substructure, using regression models. Finally, multiple QTL models were constructed by backward selection from a regression model containing all significant markers from the single QTL analyses. In addition to the association analyses per trial, genotype by environment interaction was investigated across the six trials. Landraces seemed best adapted to low yielding environments, while old and modern entries adapted better to high yielding environments. The number of QTL and the magnitude of their effects were comparable for low and high input conditions. However, none of the QTL were found within a given bin at any chromosome in more than two of the six trials. Changes in allele frequencies of marker loci close to QTL for grain yield in landraces, old and modern barley cultivars could be attributed to selection exercised in breeding, suggesting that modern breeding A. Pswarayi Á I. Romagosa

Spanish barley landraces outperform modern cultivars at low‐productivity sites

“…This phenomenon was already detected at a number of studies carried out in the Mediterranean region with different sets of local germplasm (Ceccarelli and Grando , , Ceccarelli , Pswarayi et al. ,b). These studies, however, focused mostly on field trials with very low production levels, around or below 1t/ha, whereas average grain yields of our low yielding conditions are representative of a higher productivity level, between 1.7 and 2.4t/ha (Table S4).…”

Can barley (Hordeum vulgare L. s.l.) adapt to fast climate changes? A controlled selection experiment

“…Despite the fact that ''Gammel Dansk'' performed significantly better than 'Anakin' under ambient condition, 'Anakin' showed its superiority under the future climate conditions. Differences in yield between old and new cultivars are the consequence of breeding; for example the modern cultivars have been selected by breeders for high input of nutrients, whereas landraces were grown in environments of low input (Pswarayi et al 2008). Also, the genotype's response to high [CO 2 ] is likely related to age of the cultivar/landrace.…”

Plant breeding for organic agriculture: something new?

“…• Undertake quantitative and association genetics research to understand both the extent of variation and genetic architecture of useful traits in OF [84][85][86][87].…”