Colorado State University
Kansas State University
Last Reviewed: 08/14/2017
To improve wheat, we need new genetic diversity. Without it, breeders will be unable to make the progress necessary to feed future generations. It is the key to delivering varieties to farmers with the “genetic grit” to fight devastating disease, destructive pests, and severe climates. The WGRC I/UCRC mines and harnesses the valuable attributes of wheat’s ancient ancestors to help breeders, and then farmers, produce higher yielding, better quality bread wheat.
COLLECTION AND PRESERVATION
Diversity is often thought of in terms of culture and society, but what about the diversity that lies within one tiny seed? The Wheat Genetics Resource Center (WGRC) collects and preserves genetic diversity in wheat germplasm that provides the ability to grow better wheat and in turn produce better and more nutritious wheat food products.
Raupp and the WGRC’s germplasm preservation system ensure that future generations of public and private wheat scientists will be able to tap into the novel genetics in the collection. As technology advances so does the ability of scientists and breeders to take wheat to the next level and, in the end, return a better product to the consumer.
GENETIC CURATION OF THE GERMPLASM COLLECTIONS
Wild wheat seeds, or germplasm, have been collected from their natural habitats and placed in genebanks all over the world to be used for research. The exact identity of accessions in a collection are not always reliable as systems for keeping inventory are not globally standardized. Furthermore, germplasm is often exchanged between genebanks and researchers and has passed through many hands over time. Over decades of different field collections and sharing among wheat scientists, the identity of accessions in the collection can be lost leading to the potential for redundancies and lack of important information on these valuable seeds. A researcher could be using germplasm they think are unique from one another, but in reality, they are duplicating other’s efforts or even their own.
Singh created a pipeline to identify duplicate accessions by DNA sequencing. Using this technology, Singh was able to identify those accessions that were 99% genetically similar. His findings found 27% identical accessions in the WGRC collection of tauschii, and 50-55% duplication in the International Maize and Wheat Improvement Center (CIMMYT) and Punjab Agricultural University (PAU) collections. This powerful technology does not only reduce costs attributable to redundancy, but can also be used to inventory the world’s genebanks. Plugging this pipeline into ongoing operations of the WGRC I/UCRC reduces research redundancies that cost time and money.
GENE MINING OF WILD TETRAPLOID WHEAT AND AEGILOPS TAUSCHII CORE SETS
Contained in the WGRC collections and other genebanks are thousands of accessions of wild wheats. Research has shown that within these wild relatives of wheat is the genetic potential to combat diseases, pests, and adverse environmental conditions facing wheat growers. However, the cost to mine all of these wild accessions for valuable genes and bring these genes into cultivated wheat would be much too costly.
After leveraging the germplasm redundancy pipeline developed by Narinder Singh, Vijay Tiwari applied genomic tools to shed light on which accessions have the most important alleles and valuable qualities. Dr. Tiwari’s work serves to create guides for breeders to find sought after genetics within the wild species. Think of it as a genetic shopping cart where breeders can trace accessions with valuable genes for wheat improvement to exploit in their breeding programs.
SYSTEM FOR EFFICIENT GENE TRANSFER FROM WILD INTO CULTIVATED WHEAT (PATENT PENDING)
Taking a gene from a wild wheat into a cultivated wheat can create a better plant, but the actual process is quite challenging. Wheat is made up of 3 progenitors, or descendants. The combination of the 3 genomes (A, B and D), in part, is what gives wheat its amazing properties that consumers love for their breads and cookies. However, built-in to the biology of wheat are mechanisms inhibiting the shuffling of genes from one genome to another. This shuffling, also known as recombination, is limited from A to A, B to B, and D to D. In the context of bringing useful genes from wild into cultivated wheat, this means researchers are obstructed from bringing in genes from distant wheat relatives.
Research Associate, Dr. Dal Hoe Koo at the WGRC I/UCRC has developed a system to greatly increase the efficiency with which valuable genes from wild wheat relatives can be transferred into elite bread wheat lines. This improved system can reduce the time needed to capture genes for improving wheat from decades to years.
WSM3 (GERMPLASM RELEASE)
Reflecting the benefit of center membership, the WGRC released to members only a new germplasm with resistance to wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV). WGRC I/UCRC members have a two-year exclusive access to this material before it is openly available through a public WGRC release. WSMV is transmitted by the wheat curl mite, leading to destructive disease epidemics in both Kansas and wheat fields worldwide. WGRC scientists have mined the wheat gene pool and found the WSM3 gene in a distant relative of wheat, Thinopyrum intermedium and used directed chromosome engineering to transfer it to wheat. After years of dedicated work, this unique resistant gene is ready to mobilize in breeding programs.
GENOMIC BASED TRAIT ANALYSIS
The Aegilops tauschii core set accessions contain contrasting observable characteristics for many resistance traits such as leaf rust, stem rust, Hessian fly, greenbug and others. This provides an opportunity to create populations that have both resistant and susceptible individuals from core accessions where many resistance genes can be simultaneously mapped in the same cross. At the same time, Ae. tauschii offers a simpler system, relative to bread wheat, for mapping of novel resistant genes. WGRC has identified 40 genetically diverse accessions, which represent more than ~90% of the genetic diversity of the species. We therefore propose to create mapping populations from intercrosses among accessions of the core set and will use an efficient genetic mapping approach to rapidly examine the genetic basis of useful traits in each accession. Our study will provide solid genetic information for the utilization of these tauschii accessions in wheat breeding and germplasm improvement.
The Kansas Wheat Innovation Center (KWIC), located in Manhattan, KS, is the home for the WGRC and offers state-of-the-art research and office facilities owned and operated by wheat growers built on Kansas State University property. KWIC is designed to facilitate public/private collaborations and partnerships to accelerate the delivery of innovations to Kansas’ wheat farmers.
• 15,000 square feet of research laboratories and all the equipment necessary to perform experiments and
processes related to doubled haploid production, genetics and molecular research.
• 20,000 square feet of greenhouses: Including air-conditioned bays.
• 10,000 square feet of office space.
Housed at the Kansas Wheat Innovation Center and funded through the Economic Development Administration and the Kansas Wheat Commission, the WGRC Seed Storage Room contains a priceless working collection of wild wheats (4,000), unique genetic stocks (3,500), and mapping populations (8,500).