QTL mapping of plant height, spike length, peduncle length and number of grains per plant in barley (Hordeum vulgare L.) using 'Steptoe/Morex' DH population grown in northwest of China

In the present study, 120 out of 150 barley double haploid lines, obtained by crossing 'Steptoe' x 'Morex', were screened for the 4 traits including plant height, peduncle length, spike length and grains plant-1, during three crop years in the area of Northwestern China. Quantitative trait loci (QTL) mapping was performed from the available genotype datasets using the 4.1Version of QTL IciMapping. In total, 15 QTLs were mapped on six linkage groups (1H, 2H, 3H, 4H, 5H and 7H) which explained 5.42% to 47.27% phenotypic variation. Four QTLs were recognized in three years for plant height including two QTLs of major impact, one on chromosome 2H in 2014-15 and 2015-16, and the other was detected only in 2016-17 on chromosome 4. While for spike length, four QTLs were found. Six QTLs were identified underlying the trait peduncle length with three major QTLs, two on chromosome 2H in 2015-16 and 2016-17, and one on 3H in 2014-15 and 2015-16. One major QTL for the trait grains plant-1 was identified in 2015-16. Our study could lay the foundation for the fine mapping of agronomic traits studied and could increase the efficiency of marker assisted selection (MAS) in barley breeding programs aiming at improvement of these traits. (author)