Domestic oat (Avena sativa L.) is an ancient crop that was domesticated over 3,000 years ago as a weed in wheat and barley fields. Oats have low environmental impact, significant health benefits and the potential to replace food products of animal origin. However, the lack of genomic resources has prevented the application of modern plant breeding methods.
An international research team, including researchers from the IPK Leibniz Institute, has published a high-quality reference genome of A. Sativa and its closest wild relatives. This Avena genus resource will help leverage knowledge of other cereal genomes, improve our understanding of basic oat biology, and accelerate genomics-assisted breeding.
Oats are a world crop. It currently ranks seventh in grain production. Compared to other cereals, the crop requires fewer insecticides, fungicides and fertilizer treatments. Oats have seen a revival in recent years, especially thanks to oat milk.
“Oat milk is a very high quality product that tastes great and serves as a vegan milk substitute”, says Dr. Martin Mascher, head of the “Domestication Genomics” research group at the IPK Leibniz Institute and one of the authors of the study. Unlike wheat and barley, oats are eaten directly. “While barley is used for brewing and wheat for baking bread, oats, in the form of rolled oats, remain very close to the original grain.”
Oats belong to the Poaceae grass family, which also includes wheat, rice, barley, common millet, corn, sorghum, and sugar cane. Avena species can be found growing wild in the Mediterranean, the Middle East, the Canary Islands, and the Himalayas.
Oat is a hexaploid, meaning its genome is made up of three subgenomes donated by three wild Avena species over the past 10 million years.
Individual subgenomes have also been replaced over the long evolutionary history of oats. Therefore, oats have a very complex genome which differs significantly from that of wheat and barley. “The oat genome is structurally similar to wheat and barley genomes, but frequent genomic rearrangements in oats have resulted in mosaic-like genome architecture,” explains Dr. Mascher, who is also a member of the German Center for Integrative Biodiversity Research (iDiv).
“It is now possible for the first time to link individual genes to agronomic traits in oats,” says Dr. Martin Mascher. Researchers present detailed analyzes of gene families implicated in human health and nutrition, complementing evidence supporting the safety of oats in gluten-free diets, and sequencing-map an agronomic trait related to the efficiency of water use.
With the chromosomal rearrangements in a typical spring oat cultivar now identified, breeders and researchers will have access to a resource comparable to the genomes of wheat and barley, which may help overcome breeding barriers caused by lack of genomic sequence information.
A viable approach to fine-tune oat varieties is to use the reference genome to map genes associated with agronomic and human nutrition-related traits. “Modern breeding strategies such as genome editing and the gene pyramid can now be more easily applied to oats to develop varieties that meet the growing global demand for oat-derived products,” explains the Dr Masher.
“After barley, wheat and rye, the IPK Leibniz Institute has once again demonstrated its leadership in the elucidation of genome sequences.” says Professor Nils Stein, head of the IPK research group “Genomics of Genetic Resources” and co-author of the study.
(Source: European Seeds)
First published: May 26, 2022, 07:30 IST