Wild emmer genome architecture and diversity elucidate wheat evolution and domestication

Authors: AVNI, RAZ - Tel Aviv University; NAVE, MORAN - Tel Aviv University; BARAD, OMER - Nrgene; BARUCH, KOBI - Nrgene; TWARDZIOK, SVEN - Helmholtz Centre; GUNDLACH, HEIDRUN - Helmholtz Centre; HALE, IAGO - University Of New Hampshire; MASCHER, MARTIN - Leibniz Institute Of Plant Genetics And Crop Plant Research; SPANNAGL, MANUEL - Helmholtz Centre; WIEBE, KRYSTALEE - University Of Saskatchewan; JORDAN, KATHERINE - Kansas State University; GOLAN, GUY - Hebrew University Of Jerusalem; Faris, Justin; DISTELFELD, ASSAF - Tel Aviv University

Submitted to: Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/8/2017
Publication Date: 7/7/2017
Publication URL: http://handle.nal.usda.gov/10113/5801901
Citation: Avni, R., Nave, M., Barad, O., Baruch, K., Twardziok, S.O., Gundlach, H., Hale, I., Mascher, M., Spannagl, M., Wiebe, K., Jordan, K.W., Golan, G., Deek, J., Ben-Zvi, B., Ben-Zvi, G., Himmelbach, A., MacLachlan, R.P., Sharpe, A.G., Fritz, A., Ben-David, R., Budak, H., Fahima, T., Korol, A., Faris, J.D., Hernandez, A., Mikel, M.A., Levy, A.A., Steffenson, B., Maccaferri, M., Tuberosa, R., Cattivelli, L., Faccioli, P., Ceriotti, A., Kashkush, K., Pourkheirandish, M., Komatsuda, T., Eilam, T., Sela, H., Sharon, A., Ohad, N., Chamovitz, D.A., Mayer, K.F.X., Stein, N., Ronen, G., Peleg, Z., Pozniak, C.J., Akhunov, E.D., Distelfeld, A. 2017. Wild emmer genome architecture and diversity elucidate wheat evolution and domestication. Science. 357:93-97.

Interpretive Summary: Wheat (Triticum spp.) is one of the founder crops that likely drove the Neolithic transition to sedentary agrarian societies in the Fertile Crescent over 10,000 years ago. Identifying genetic modifications underlying wheat's domestication requires knowledge of the genome of its allo-tetraploid progenitor, wild emmer (T. turgidum ssp. dicoccoides). We report a 10.1-gigabase assembly of the 14 chromosomes of wild tetraploid wheat, as well as analyses of gene content, genome architecture, and genetic diversity. With this fully-assembled polyploid wheat genome, we identified the causal mutations in Brittle Rachis 1 (TtBtr1) genes, which control the premature disarticulation of the heads, a trait known as shattering. The mutations in the TtBtr1 genes were key to the domestication of wheat because farmers were subsequently able to harvest the grains while still attached to the plant. This reference assembly will serve as a resource for accelerating the genome-assisted improvement of modern wheat varieties.

Technical Abstract: Wheat (Triticum spp.) is one of the founder crops that likely drove the Neolithic transition to sedentary agrarian societies in the Fertile Crescent over 10,000 years ago. Identifying genetic modifications underlying wheat's domestication requires knowledge of the genome of its allo-tetraploid progenitor, wild emmer (T. turgidum ssp. dicoccoides). We report a 10.1-gigabase assembly of the 14 chromosomes of wild tetraploid wheat, as well as analyses of gene content, genome architecture, and genetic diversity. With this fully-assembled polyploid wheat genome, we identified the causal mutations in Brittle Rachis 1 (TtBtr1) genes controlling shattering, a key domestication trait. A study of genomic diversity among wild and domesticated accessions revealed genomic regions bearing the signature of selection under domestication. This reference assembly will serve as a resource for accelerating the genome-assisted improvement of modern wheat varieties.