Mapping of Forage Quality-Related Genomic Locations of Barley under Drought Stress Condition



Despite the importance of forage quality to animal performance, the quality of barley as a feed and forage crop has not been taken into consideration as a selection criterion in its breeding programs. In order to map the genomic regions affecting barley forage quality, two experiments were conducted while employing 72 doubled haploid lines and their two parents (‘Steptoe’ and ‘Morex’), at the research farms of the Faculty of Crop and Animal Sciences, University College of Agriculture and Natural Resources, University of Tehran and as well at the Agriculture and Natural Resources Research Station, Sistan, in 2007. The experiments were arranged in a randomized complete block design with two replications. Each plot consisted of four rows, 3m in length and spaced 25cm apart. The main effect of genotype was highly significant for all the studied traits. Transgressive segregation in either direction (positive and negative) was observed for all the studied traits. Twenty-eight QTLs controlling different studied traits were identified. Phenotypic variance explained by these QTLs varied from 4.18 to 38.92%. The highest LOD scores were obtained for the acid detergent fiber on chromosome 2H. QTLs for forage quality indices were detected on chromosomes 1H, 2H, 5H and 6H. Most mapped QTLs appear to benefit from stablility between locations. Therefore, gain through marker-assisted selection (MAS) in this population would be efficient