Quantitative trait locus analysis of nitrogen use efficiency in barley (Hordeum vulgare L.) Gashu Aynalem Kindu • Jianjun Tang • Xinyou Yin • Paul C. Struik Received: 20 November 2013 / Accepted: 25 April 2014 Ó Springer Science+Business Media Dordrecht 2014 Abstract Quantitative trait locus (QTL) analysis of nitrogen use efficiency (NUE) of barley (Hordeum vulgare L.) was conducted on data generated from two pot experiments carried out in 2005 (using four nitrogen rates) and 2008 (with three rates) with AFLP markers and 94 recombinant inbred lines (RILs) of the Prisma 9 Apex mapping population. In total 41 QTLs were detected on 6 chromosomes and for 18 traits in both trials. About 95 % of the detected QTLs were with major additive effects. The percentage of vari- ance accounted for by individual QTLs in the multiple QTL mapping model ranged from 8.4 to 54.4 % across all mapped traits in both years. Fifteen QTLs were related to NUE and its components; most of these QTLs were detected at lower nitrogen rates and none at the highest rate in both trials. These QTLs were found on Chromosomes 3(3H) and 7(5H) in 2005 and Chromosome 2(2H) in 2008. Except for the QTLs of plant height and NUE based on grain yield, none of the QTLs which were detected for a given trait in 2005, expressed themselves in 2008 irrespective of the nitrogen levels. QTLs controlling some traits were co- located in each year, and QTLs for many traits were detected on the same chromosome and close to the denso locus. Further research is needed to investigate the possibility to reduce nitrogen fertilizer require- ments through breeding while maintaining high yield of barley. Keywords Barley  Hordeum vulgare  Nitrogen use efficiency (NUE)  Quantitative trait locus (QTL)  Recombinant inbred lines (RIL) Introduction Increased nitrogen use efficiency (NUE) is among multiple objectives in modern agriculture (Gastal and Lemaire 2002). NUE has been usually defined as the yield of grain (harvested product) achieved per unit of available N in the soil (Moll et al. 1982; 1987). Crop Gashu Aynalem Kindu and Jianjun Tang contributed equally to the work Electronic supplementary material The online version of this article (doi:10.1007/s10681-014-1138-9) contains supple- mentary material, which is available to authorized users. G. A. Kindu  X. Yin (&)  P. C. Struik Department of Plant Sciences, Centre for Crop Systems Analysis, Wageningen University, PO Box 430, 6700, AK, Wageningen, The Netherlands e-mail: xinyou.yin@wur.nl Present Address: G. A. Kindu Adet Agricultural Research Centre, PO Box 08, Bahir Dar, Ethiopia J. Tang College of Computer and Information Engineering, Jiangxi Agricultural University, Nanchang 330045, Jiangxi, People’s Republic of China 123 Euphytica DOI 10.1007/s10681-014-1138-9