Efficient characterization of Tetraploid Wheat Plant Genetic Resources for wheat resilience improvement

W244: Climate change poses major challenge for global wheat production and thus food security. Drought, heat, salinity and recurrent rust, septoria and fusarium epidemic waves are among the most common abiotic and biotic stresses limiting wheat crop productivity and sustainability worldwide. If adequately characterized, natural variants present in underutilized plant genetic resources (PGRs) are potentially valuable for providing improvements on resilience to abiotic stress and durable resistance to plant pathogens. In this context, Golden-standard reference genomes as well as characterized PGRs are instrumental. Both Triticum aestivum and Triticum turgidum ssp. durum share BB and AA genomes inherited from wild and domesticated emmer throughout complex steps of domestication, spread and migration events from the Fertile Crescent to diverse environments and agro-ecological conditions. With the aim of facilitating germplasm characterization and use, we assembled two comprehensive and complementary tetraploid collections: i) the Global Durum Wheat Panel (GDP) and the Tetraploid wheat Global Collection (TGC, Maccaferri et al. Nature Genetics 2019). GDP was established through a cooperative effort in the frame of the Wheat Initiative. GDP, currently maintained by ICARDA, was assembled by bringing together the durum wheat cultivated germplasm from more than 50 countries worldwide, including ca. 500 cultivars and 400 landraces, pre-breeeding lines and emmer. The Tetraploid wheat Global Collection (TGC), of 1,856 single-seed descent derived-genotypes, represents 11 tetraploid BBAA wheat taxa covering the whole distribution range. The Illumina 90K wheat SNP array was used to characterize both collections. Ca. 20,000 unique, non-redundant, single Mendelian SNP markers that were both genetically and physically mapped were use to obtain a haplo-based map of germplasm. We provide a detailed dissection of the huge reservoir of genetic diversity available in these two tetraploid genetic resources and examples of successful utilization of these resource to conduct GWAS for traits related to improvement of wheat sustainability and adaptation to climate change effects.