The Power of High Quality Reference Sequences for Climate Resilient Wheat and Rice

Cereals contribute more than 60% of the calories consumed by humans and more than 80% of these calories are derived from bread wheat (Triticum aestivum) and rice (Oryza sativa).  Wheat and rice production must expand significantly in the midst of a steadily changing climate to ensure sufficient calories for a global population expected to exceed 10 billion by 2050. Both will need a full complement of resources and tools to resist and adapt to increased abiotic and biotic stressors.  The critical foundation for rapid and continuous varietal improvement will be a high-quality, reference genome sequence coupled with a complete understanding and capacity for optimization of their phytobiomes.  Currently, rice is the only crop for which a finished genome sequence exists and this sequence coupled with enhanced host-pathogen-environment studies has led to a paradigm shift in rice breeding.  Achieving a high quality, reference sequence of the bread wheat genome, however, is taking longer because of the sequencing cost and bioinformatic challenges associated with the assembly of the mostly repetitive 17 Gb hexaploid genome.  To reduce the complexity of the wheat genome, the IWGSC follows a chromosome-specific approach to develop physical maps, shotgun sequencing, and high quality sequencing of the Minimum Tiling Paths while moving towards a gold standard reference sequence.  Already, the IWGSC resources are being utilized already to accelerate gene discovery and breeding for traits related to climate change.  Examples of how wheat and rice genomic resources are being used to develop climate resilient varieties will be presented.