Identifying DNA Variants That Control Maize Domestication, Adaptation and Nutrition

Maize, like many crops, is extremely diverse, especially when compared to mammalian diversity.&nbsp; In the case of maize, that diversity is the product of evolution and adaptation over the last several million years.&nbsp; There are more than 100 million common genetic variations distributed across the maize genome, which makes any two maize varieties likely to be far more different genetically than humans and chimps are from one another.&nbsp; This tremendous natural diversity has already allowed maize to respond to selection in a multitude of ways, and provides the potential for creating a more sustainable crop that satisfies some of the desperate nutritional needs facing many parts of the world. Future improvement of maize will be greatly accelerated through genomics. &nbsp;However, until recently, the tools of genomics could only be applied to a few maize varieties, due to the high cost and the labor involved. But this has all changed in the last few years. &nbsp;We have developed major technological and analytical advances that allow the diverse genomes of maize to be sequenced and profiled exponentially faster and more effectively than before.&nbsp; This process has now identified more than one thousand genes controlling the adaption <a href="#_msocom_1">[R1]</a>&nbsp;of maize to diverse environmental circumstances, and to modern agricultural practices.&nbsp; Through extensive field testing across the globe, genetic variants controlling nutritional value and adaptation to different environments are being identified.&nbsp; These new techniques allow us to tap the natural diversity of landraces (historical farm varieties), permitting identification and efficient utilization of a tremendous range of existing adaptations.&nbsp; As a result, breeders are now more effectively harnessing the natural diversity of maize to improve vitamin A content, acid soil tolerance, drought tolerance, nitrogen use efficiency, and disease resistance. Although the basic road map for analyzing the genome for useful adaptations is now in place, the journey to link the majority of the millions of functional gene variants to individual traits has only just begun.&nbsp; This journey will be greatly hastened by the effective integration of a wide assortment of powerful new technologies.&nbsp; Over the next several years, a key issue will be how to best harness the tools of breeding, engineering, and computer science to collect and analyze vast quantities of phenotypic data from around the globe. &nbsp;We have the tools, and now scientists, farmers, and the public need to consider how we can best work together to achieve the most sustainable agriculture possible.