Detecting useful genetic diversity from a spanish landrace to improve an elite cultivar

Abstract

Spanish Barley Core Collection (SBCC) has shown genetic variability with potential interest for breeding, particularly aiming at adaptability to Mediterranean environments. Cierzo, a successful elite barley cultivar selected under Spanish Mediterranean conditions, was chosen as recurrent parent of a backcross scheme. The donor parent, SBCC073, was selected among the SBCC lines due to its good yield performance under drought conditions. Under an augmented design with incomplete blocks, yield and drought-related traits and flowering time were evaluated in two field trials in Zaragoza (Spain). Raw data were spatially corrected using a moving average correction approach. Genotyping of 264 lines was carried out using the Barley Illumina iSelect 50k SNPchip. A genetic map was generated with 12667 SNPs covering the 7 linkage groups. Using the results of two years of field trials (2014-2015 and 2015-2016), we identified regions with stable QTLs. Among them, SBCC073 contributed favorable alleles for vegetative growth, measured in different moments of development, with a QTL in the region of 5H 138.5 cM, related also to flowering. The candidate of this region could be the response-regulator PRR95, component of the circadian clock. Another important region was found on 6H, at 59.1 cM, with QTLs for plant height, thousand kernel weight and yield, being the SBCC073 allele responsible of increasing plant height and thousand kernel weight, and reducing yield. No candidate gene has been found for this region yet. The QTLs found would be useful to develop improved breeding strategies based on exploiting the SBCC genetic diversity.