Agronomic and genetic assessment of terminal drought tolerance in two-row spring barley

Abstract

Barley (Hordeum vulgare L.) ranks fourth in global cereal grain production and is an important crop for animal feed, malting, and human consumption. Identification of two-row barley germplasm with drought tolerance can increase genetic diversity and facilitate future barley breeding efforts. The present study evaluated 480 two-row spring barley accessions from the USDA National Small Grains Collection across two years of irrigated and terminal drought trials for grain yield, test weight, protein content, thousand-kernel weight, and kernel size. Twenty accessions were identified that showed stable high yield, high test weights, and low protein content across trials. An additional 10 accessions were identified with stable high yield, high test weights, and high protein across trials. Genome-wide association mapping with 6,366 single nucleotide polymorphism (SNP) markers revealed 15 drought-stable genetic loci significantly (false discovery rate-adjusted P