The durum wheat community developed a long-term collaborative project to switch durum wheat from orphan to crop for the future. The Wheat Initiative Durum wheat expert working group, CIMMYT, ICARDA and public and private partners worldwide joined efforts towards deciphering, cataloguing, and making available the huge amount of untapped diversity of tetraploid wheat germplasm including 11 T. turgidum subspecies. Tetraploid genetic diversity was shaped by exposure to diverse environmental conditions, pathogen and human selection, thus providing valuable alleles for resilience to abiotic and biotic stresses.

The Svevo Platinum reference sequence was used as a framework to study diversity and assemble a comprehensive, highly diverse Global Durum Genomic Resource (https://wheat.pw.usda.gov/GG3/global_durum_genomic_resources) including the Global Tetraploid Collection (GTC with 1,856 accessions, Maccaferri et el. 2019, Nature Genetics) and the Global Durum Panel (GDP with 1,033 accessions, Mazzucotelli et al. 2020, Frontiers). Joint molecular haplotype analysis of tetra- and hexa-ploid haplotype diversity led to characterization of genomic and demographic structure including haplotype transmission from Triticum dicoccoides to T. dicoccum to durum and bread free-threshing forms.

Based on these results, we assembled the Tetraploid wheat Core Collection (TCC; 432 accessions), effectively capturing most of the diversity in tetraploids. TCC was used to develop the tetraploid wheat pangenome which includes a golden level of 40 accessions PACBIO25X sequenced plus Bionano Optical mapping and Hi-C, a silver level (PACBIO10X) of 100 accessions, and up to 432 accessions in total for the bronze level.

The Global Durum Genomic Resource is currently under distribution and phenotypic evaluation. Phenotypic characterization started by targeting: (i) phenology, (ii) resistance to main wheat diseases, (ii) root system architecture, (iii) grain Yield components, spike fertility, and grain quality. GWAS allowed to discover loci relevant for wheat breeding and haplotype-tagging KASP markers were developed based on a highly efficient custom-made KASP primer design pipeline.

Main results will be presented and discussed, including the identification and tracing of favorable alleles. The Global Durum Genomic Resource is available at UNIBO, CREA and ICARDA. Genomics data are accessible on GrainGenes and will be continuously updated.

Acknowledgements:

Research supported by IWYP project “ROOTY”, the PRIMA2019-Section 2 “CEREALMED-Enhancing diversity in Mediterranean cereal farming systems”, the H2020 FP7 “INNOVAR”- Next generation variety testing for improved cropping on European farmland, the FACCE JPI-SusCrop “WHEASECURITY”, “AGRITECH - National Research Centre for Agricultural Technologies”, the PRIN “PANWHEATGRAIN”, “INNOWHEATRES” projects and by National Projects in Canada, USA, Australia and Europe.

Emails

"Marco Maccaferri", marco.maccaferri@unibo.it; "elisabetta mazzucotelli", elisabetta.mazzucotelli@crea.gov.it; "Cristian Forestan", cristian.forestan@unibo.it; "Jennifer Ens", jennifer.ens@usask.ca; "Harmeet Chawla", harmeet.chawla@umanitoba.ca; "Victor Llaca", victor.llaca@corteva.com; "Kevin Fengler", kevin.a.fengler@corteva.com; "Primetta Faccioli", primetta.faccioli@crea.gov.it; "Matteo Bozzoli", matteo.bozzoli2@unibo.it; "Francesca Desiderio", francesca.desiderio@crea.gov.it; "Anna Maria Mastrangelo", annamaria.mastrangelo@crea.gov.it; "Daniela Marone", daniela.marone@crea.gov.it; "Thorsten Schnurbusch", schnurbusch@ipk-gatersleben.de; "Matt Hayden", matthew.hayden@ecodev.vic.gov.au; "Raj Pasam", raj.pasam@ecodev.vic.gov.au; “Harbans Bariana” Harbans.bariana@sydney.edu.au; “Urmil Bansal”, urmil.bansal@sydney.edu.au; "Agata Gadaleta", agata.gadaleta@uniba.it; "Karim Ammar", k.ammar@cgiar.org

"Rajeev Varshney", rajeev.varshney@murdoch.edu.au; "Brande Wulff", brande.wulff@kaust.edu.sa

"Brian Steffenson", bsteffen@umn.edu; "Justin Faris", justin.faris@usda.gov; "Steven Xu", steven.xu@usda.gov

"Taner Sen", taner.sen@usda.gov; "Eduard Akhunov", eakhunov@ksu.edu; "Dario Copetti", dcopetti@cals.arizona.edu; "Giovanni Melandri", gmelandri@arizona.edu; "Nicola Pecchioni", nicola.pecchioni@crea.gov.it; "Pasquale Devita", pasquale.devita@crea.gov.it; "Nathalie Chantret", nathalie.chantret@inrae.fr; "Vincent Ranwez" vincent.ranwez@supagro.fr; "Sharpe Andrew", andrew.sharpe@gifs.ca; "Sean Walkowiak", sean.walkowiak@grainscanada.gc.ca; "Aldo Ceriotti", aldo.ceriotti@ibba.cnr.it; "Gabriella Sonnante", gabriella.sonnante@ibbr.cnr.it; "Stefania Masci", masci@unitus.it; "Francesco Sestili",francescosestili@unitus.it; "Michele Morgante", michele.morgante@uniud.it

" Filippo Bassi", f.bassi@cgiar.org; " Michael Baum", m.baum@cgiar.org; " Gina Zastrow-Hayes" gina.zastrow-hayes@corteva.com; "Curtis Pozniak", curtis.pozniak@usask.ca; "Luigi Cattivelli", luigi.cattivelli@crea.gov.it

"Roberto Tuberosa", roberto.tuberosa@unibo.it