association mapping for root characteristics in barley (hordeum vulgare)

abiotic stresses and lack of nutrients are one of the most important factors in reducing the crop yield.  vigorous and developed roots can facilitate uptake of water and nutrients more efficiently making it essential for enhancing the yield. association mapping is currently one of the approaches for detecting quantitative trait loci (qtls) influencing complex traits. this approach was used to detect qtls for some root traits in a diverse collection of 100 winter barley (hordeum vulgare). association panel was sown in the greenhouse in a randomized complete block design with three replications and root dry weight, root volume, average diameter and average secondary roots were measured. population was genotyped using 3964 snps having minor allele frequencies (mafs) greater than 10 percent. the population was classified in two subpopulations based on spike row number. in the whole genome, average ld was observed to decay at 4cm. using a mixed linear model with kinship for controlling spurious ld effects, we found a total of 15 significant marker-trait associations. snp_2981 was associated with the number of secondary roots at maximum -log p. comparative study with previously mapped agronomic traits showed that several qtls of root traits were related to the characters such as yield, kernels per spike, heading date, lodging and plant height.