Efficient Curation of Gene Banks Using Next-Generation Sequencing

The reduction of genetic diversity in elite germplasm of many crop species poses a problem in terms of crop improvement that also limits the modern breeding efforts. The use of wild germplasm to bring in the novel genetic diversity from wild germplasm can help mitigate this issue. Gene banks play an important role by facilitating ex-situ conservation of the wild germplasm and providing a platform for germplasm sharing. More than 7 million plant accessions are stored in over 1700 gene banks around the world, and millions of dollars are spent every year in maintaining them. Every gene bank is limited in their capacity and resources; therefore, the better management strategies are needed. Modern next-generation sequencing techniques, such as genotyping-by-sequencing (GBS), along with bioinformatics tools can be used to identify and remove duplicate accessions within and among gene banks. In a preliminary study, we found ~30% redundant accessions within Wheat Genetics Resource Center and two other Aegilops tauschii collections. Based on these findings, a globally unique set of accessions for a particular species can be defined that captures the genetic diversity without being redundant. In addition, these techniques can be used to infer missing information, such as ancestry and geographical origin that is often misidentified or lost. Ultimately in the long run, the removal of duplicate accessions will result in the availability of more resources for novel germplasm collection, cost reduction and efficient management of germplasm databases.