Marker-Trait Associations of Agronomic Traits in Barley (Hordeum vulgare L.) under Semi-Arid Conditions

Abstract

Heading date, plant height, and spike-related phenotypes are key traits that affect the yield potential and adaptation of barley to Mediterranean environments. These traits are controlled by a complex network of genes as well as environmental effects. Marker-trait associations (MTAs) were performed using a set of 361 barley genotypes, evaluated phenotypically for three years under semi-arid conditions. In total, 24 MTAs were detected using the recently developed GWAS method (BLINK) at –log p ≥ 5. These included one MTA with awn length (Awl) on chromosome 2H; twelve MTAs with heading date (HD) distributed over all chromosomes except 4H; three MTAs with grains per spike (GPS) on chromosomes 1H, 2H, and 6H; six MTAs were detected for plant height (PH) on 2H (2), 3H, 4H, 6H, and 7H; and two MTAs with spike length (SL) on 3H and 7H. The results showed novel and known associations between specific SNP markers and heading date, plant height, and spike-related traits, suggesting that these markers can be used in breeding programs to improve these traits in barley. This study provides valuable information for breeders and geneticists working to develop new barley varieties that are better adapted to semi-arid climates and have improved yield and quality characteristics.