Distinguished Research Professor University of Georgia Athens, Georgia
Finger millet, Eleusine coracana, is an important dryland crop in eastern Africa and southern India with the potential for production expansion by incorporating it into climate-smart agricultural production systems. In recent years, we have made great strides in developing genetic and genomic resources for finger millet. Diversity analyses have provided insight into the overall population structure of finger millet germplasm and have led to a better understanding of the, in some cases limited, variation present in breeding programs. A set of diverse finger millet lines were selected for the development of a nested association mapping (NAM) panel for future trait mapping. While awaiting completion of the NAM population, we have initiated trait analyses and identification of causal gene candidates in two wild x cultivated biparental mapping populations. These studies have reaffirmed the power of applying knowledge from model species to orphan crops to identify candidate genes for target traits, but also show that finger millet carries unique allelic variants that can reveal gene functions not previously identified in model species. The same applies to crop pathogens. We have put considerable effort into the genomic analysis of finger millet-infecting Magnaporthe oryzae strains from Ethiopia, Kenya, Uganda and Tanzania. M. oryzae infects more than 50 grass species leading to blast disease, but infection potential is typically host-specific. Our comparative studies with rice-infecting M. oryzae strains have uncovered effector genes that are uniformly absent from eastern African finger-millet infecting strains; cognate resistance genes for these effectors may be present in finger millet. If confirmed, these genes could be introduced into rice to provide a novel source of blast resistance. In summary, finger millet and, more generally, orphan crops are worth investing in for their importance in food security and climate-smart agriculture, as well as their contributions in linking genotypes to phenotypes.