RESEARCH ARTICLE Genotypic and phenotypic changes in wild barley (Hordeum vulgare subsp. spontaneum) during a period of climate change in Jordan I. Thormann . P. Reeves . S. Thumm . A. Reilley . J. M. M. Engels . C. M. Biradar . U. Lohwasser . A. Bo ¨rner . K. Pillen . C. M. Richards Received: 11 April 2016 / Accepted: 16 August 2016 / Published online: 7 September 2016 Ó Springer Science+Business Media Dordrecht 2016 Abstract Climate change and other anthropogenic disturbances can lead to the loss of genetic variation and thereby affect evolutionary potential and survival of plant populations in the wild. We examined these predictions in the primary wild relative of barley, Hordeum vulgare L. subsp. spontaneum (K. Koch) Thell., within its center of diversity, in Jordan. Changes in genotypic and phenotypic diversity were assessed using seed samples collected in 1981 and 2012 from the same 18 sites across Jordan. The overall population structure was conserved, but we observed an increase of within population genetic diversity and a reduction in population differentiation. Phenotypic variation differed among years and sites but the magnitude and direction of change variated among sites. While the sampled region became significantly hotter and drier during this period, simple correlation models did not support association between measures of climate change and the observed genetic and phenotypic changes. Agricultural activities that pro- mote disturbance and demographic fluctuations may affect crop wild relatives that grow in agricultural landscapes, in unexpected ways. The observed increase in genetic diversity within populations might be explained by increased migration or by an advan- tage of increased genetic variation in the face of variable environmental conditions. This study pro- vides a new perspective on the range of possible responses of crop wild relatives to environmental pressures. Electronic supplementary material The online version of this article (doi:10.1007/s10722-016-0437-5) contains supple- mentary material, which is available to authorized users. I. Thormann (&) Á J. M. M. Engels Bioversity International, Via dei Tre Denari 472/A, 00057 Maccarese, Rome, Italy e-mail: i.thormann@cgiar.org P. Reeves Á A. Reilley Á C. M. Richards National Center for Genetic Resources Preservation, United States Department of Agriculture-Agricultural Research Service, 1111 South Mason Street, Fort Collins, CO 80521, USA S. Thumm Á U. Lohwasser Á A. Bo ¨rner Genebank Department, Leibniz Institute of Plant Genetics and Crop Plant Research, Corrensstr. 3, 06466 Stadt Seeland, OT Gatersleben, Germany C. M. Biradar International Center for Agricultural Research in Dry Areas (ICARDA), P.O. Box 950764, Amman 11195, Jordan K. Pillen Plant Breeding, Institute for Agricultural and Nutritional Science, Martin-Luther-University Halle-Wittenberg, Betty-Heimann-Str. 3, 06120 Halle/Saale, Germany 123 Genet Resour Crop Evol (2017) 64:1295–1312 DOI 10.1007/s10722-016-0437-5