|THORMANN, IMKE - Bioversity International
|ENGELS, JAN - Bioversity International
|BIRADAR, C - International Center For Agricultural Research In The Dry Areas (ICARDA)
|LOHWASSER, ULRIKE - Leibniz Institute Of Plant Genetics And Crop Plant Research
|BÖRNER, ANDREAS - Leibniz Institute Of Plant Genetics And Crop Plant Research
|PILLEN, KLAUS - Martin Luther University
Submitted to: Genetic Resources and Crop Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/16/2016
Publication Date: 8/1/2017
Citation: Thormann, I., Reeves, P.A., Reilley, A.A., Engels, J.M., Biradar, C.M., Lohwasser, U., Börner, A., Pillen, K., Richards, C.M. 2017. Genotypic and phenotypic changes in wild barley (Hordeum vulgare subsp. spontaneum) during a period of climate change in Jordan. Genetic Resources and Crop Evolution. 64:1295-1312.
Interpretive Summary: Climate change and habitat disturbances can lead to the loss of genetic variation, affecting plant populations' ability to adapt and survive in the wild. We examined change in genetic variation in wild Hordeum species in Jordan, which is the center of diversity for domesticated barley. Genetic variation was measured using both genotypic and phenotypic markers/traits of grown-out seed samples that were collected in 1981 and 2012 from the same 18 sites across Jordan. The study region in Jordan became significantly hotter and drier during the 31 year period. However, changes in genetic and phenotypic diversity did not correspond to changed weather patterns according to simple correlation models. Instead, there was an overall increase in within-population diversity and a reduction in among-population differentiation. The observed increase in genetic diversity within populations might be explained by increased migration or by unknown advantage of mixing genes in the face of variable environmental conditions. Agricultural activities might also promote disturbance and distribution of plant populations in unexpected ways, especially for crop wild relatives. This study provides a new perspective on the range of possible responses of crop wild relatives to environmental pressures.
Technical 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 promote 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 advantage of increased genetic variation in the face of variable environmental conditions. This study provides a new perspective on the range of possible responses of crop wild relatives to environmental pressures.