DOI: 10.5061/dryad.mr070
title: Data from: Genome scan identifies flowering-independent effects of barley HsDry2.2 locus on yield traits under water deficit

description: Increasing crop productivity under climate change requires the
 identification, selection and utilization of novel alleles for breeding.
 We analyzed the genotype and field phenotype of the barley HEB-25
 multi-parent mapping population under well-watered and water-limited (WW
 and WL) environments for two years. A genome-wide association study (GWAS)
 for genotype by-environment interactions was performed for ten traits
 including flowering time (HEA) and plant grain yield (PGY). Comparison of
 the GWAS for traits per-se to that for QTL-by-environment interactions
 (QxE), indicates the prevalence of QxE mostly for reproductive traits. One
 QxE locus on chromosome 2, Hordeum spontaneum Dry2.2 (HsDry2.2), showed a
 positive and conditional effect on PGY and grain number (GN). The wild
 allele significantly reduced HEA, however this earliness was not
 conditioned by water deficit. Furthermore, BC2F1 lines segregating for the
 HsDry2.2 showed the wild allele confers an advantage over the cultivated
 in PGY, GN and harvest index as well as modified shoot morphology , longer
 grain filling period and reduced senescence (only under drought),
 therefore suggesting adaptation mechanism against water deficit other than
 escape. This study highlights the value of evaluating wild relatives in
 search of novel alleles and clues to resilience mechanism underlying crop
 adaptation to abiotic stress.
description: LOM et al
 JXB_PHENO_GENO-2Genotypic and phenotypic
 data for the HEB-25 barley mapping population grown under well-watered
 (WW) and water-limited (WL) environments for two years (2015 and 2016).
 The genotypic data: 11, homozygous for the cultivated Hordeum vulgare
 allele; 12, heterozygous; 22, homozygous for the wild donor (H.
 spontaneum). Phenotype: Heading time (HEA), defined as the time between
 sowing to time at which the first spike of 50% of the plants in a plot
 reaches BBCH49 (first awns visible), was recorded based on daily
 inspection. Days from sowing to stage BBCH87 (hard dough: grain content
 solid: fingernail impression held) was recorded as maturity (MAT). At
 maturity, plant height (HEI) was measured from the soil surface to the
 base of the three first spikes per plot. At full grain maturity and after
 plants were fully dried, all aboveground biomass was harvested and weighed
 to determine total dry matter (TDM). Notably, all the free-thrashing
 material (app. ¼ of the material) was caged between BBCH49 and BBCH87 to
 avoid loss of spikes. Spikes were then threshed and weighed to determine
 plant grain yield (PGY). Finally, grains were counted to estimate grain
 number per mini-plot (GN) and average grain weight (GW). Harvest index
 (HI) was calculated as the ratio between PGY and TDM. Vegetative dry
 matter (VDW) was calculated by subtracting PGY from TDM. The grain-filling
 period (GFP) was calculated by subtracting HEA from MAT. Trait values were
 adjusted based on the ratio between population mean values in the two
 years. The adjusted HEB means across years were used in the
 GWAS.