Diversity Arrays Technology: A Novel Tool for Harnessing the Genetic Potential of Orphan Crops

Genetic diversity is the raw material available to plant breeders. By productively recombining genetic diversity, plant breeders have been successfully producing, year after year, improved cultivars of the major domesticated species used in the world’s diverse agricultural systems. Molecular genetic markers offer a powerful tool to accelerate and refine this process. Existing genetic marker (genotyping) technologies, mostly developed for applications in human health, have also been applied successfully to agricultural species, but their cost remains prohibitive for most agricultural applications. This is particularly true for species for which no molecular data and very limited resources are available. Because of the limitations of existing marker technologies, we have developed Diversity Arrays Technology (DArT), a novel method to discover and score genetic polymorphic markers. DArT is a sequence-independent, high-throughput method, able to discover hundreds of markers in a single experiment. DArT markers are typed in parallel, using high-throughput platforms, with a low cost per data point. With DArT, plant breeders, plant ecologists, as well as the managers of the germplasm collections, will be able to perform genetic analysis in a cost-effective and high-throughput manner. DArT fingerprints will be useful for accelerating plant breeding, and for the characterization and management of genetic diversity in domesticated species as well as in their wild relatives. We have developed DArT successfully for rice, barley, wheat, and cassava. We have also produced a dedicated data management and analysis package, a key part of the technology, entirely built from Open Source components. Work is in progress to establish DArT for other species of importance to tropical agriculture: pigeonpea, sorghum, and chickpea. We have a strong interest in developing partnerships to establish DArT for many species, and we are developing a network model for the delivery of technology to users.