Most of the major cereal crops in the world were domesticated nearly ten thousand years ago and very few have been developed since then. To cope with a burgeoning population and increasingly frequent and extreme climate events, new, resilient, high-yielding grains are needed. While it is possible to identify new, adaptive traits and breed them into pre-existing crops, this often takes over a decade and is highly dependent on the availability of improvement techniques. As an alternative to preparing our current staple crops for future environmental resilience, it may be more beneficial to domesticate, improve, and develop breeding techniques for underutilized grains that are already resistant to drastic environmental change, such as teff (Eragrostis tef) and other members of the Eragrostis family. Teff is the only known crop plant that is able to withstand high temperatures, arid conditions, and both drought and flooding. Despite the fact that millions of Eastern Africans consume teff every day, the plant has not undergone extensive breeding; even modest genetic improvements will increase yield dramatically. To improve and/or domesticate members of the Eragrostis family rapidly, new techniques will be employed to introduce changes into teff versions of genes that have been shown to be important in the domestication of other cereals. This approach would thus mimic the beneficial agronomic traits that arose naturally and were selected for in other cereal crops by ancient farmers thousands of years ago. The information gained from this study will then be applied to domesticate weeping lovegrass (Eragrostis curvula), an edible, perennial teff relative that has the remarkable ability to produce seeds in the absence of fertilization.
Teff is the only known, C4 crop able to withstand high temperatures and both drought and flooding. However, teff has several negative agronomic traits, including highly indeterminate spikelets, small seeds, extensive tillering, and thin stems susceptible to lodging, traits that need to be modified before teff can be adopted globally as a serious alternative crop. These issues will be addressed using CAS9 nickase/deaminase fusions to introduce SNPs into the negative regulatory elements of several known domestication/yield genes. This project will jump-start the domestication process by creating dominant, advantageous phenotypes mimicking the agronomic traits selected for by ancient farmers. As a test of this approach to speeding the domestication process, successful guide RNAs identified in teff will then be used to attempt to domesticate Eragrostis curvula (weeping lovegrass), a resilient perennial plant that undergoes apomixis and has been used as a famine food in Africa.
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