Francis C. Ogbonnaya, F. Makdis, M. El Bouhssini, K. Nazari, O. Abdalla,
W. Tadesse, I. Tahir, M. Baum
Biodiversity and Integrated Gene Management Program, ICARDA

Three major crops, wheat (Triticum aestivum, L.), rice (Oryza sativa, L.) and maize (Zea mays, L.) provide about two-thirds of all energy in human diets, and production systems involving these crops provide the mainstay of the global food supply linked with food security. The challenges of feeding a world population of 9 billion people, as projected by mid-century, are immense and sustainability of the natural resource base must be preserved. In order to meet the food and fiber needs of this ever increasing population, far-reaching increases in agricultural output are required. However, the demand for wheat and wheat products is projected to increase by 20-30% in the future particularly in developing countries. This is against the backdrop of continuing stagnation in current production with wheat demand outstripping supply in 6 out of the last 10 years. At the same time, climate-change induced temperature increases as well as the constant threats of evolving disease and insect-pest virulence continue to undermine current efforts.
Incorporation of genetic diversity into elite wheat cultivars has long been recognized as a means of improving wheat productivity and securing global wheat supply. Synthetic hexaploid wheat (SHW) recreated from its two progenitor species, the tetraploid, Triticum turgidum (2n=4x=28, AABB) and its diploid wild relative, Aegilops tauschii (2n=2x=14, DD) is a useful resource of new genes for bread wheat improvement. Within the last decade, it has clearly been demonstrated that SHW can be used to improve the efficiency of wheat germplasm enhancement for biotic stresses and increasingly for abiotic stresses. We present results on previous and on-going efforts at the characterization of SHW for various foliar and root diseases, the identification of novel multiple disease resistance, their transfer into bread wheat including development of wheat germplasm with enhanced biotic and abiotic stress tolerance. We present the application of genomic tools to further expedite the introgression of these novel exotic alleles into locally adapted germplasm for further wheat improvement.We also examined the yield of synthetic derived wheats grown as a means of improving yield potential and productivity and found for most agronomic traits. As a result, it was revealed that synthetic-derived wheat have greater range of yield and yield enhancing variation than commercial cultivars under marginal and optimal yielding environments worldwide. The surges in exploiting this mode of genetic variability hold the greatest potential in meeting the targets of projected wheat productivity gains and secure global food security.
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Ogbonnaya, F.C.; Halloran, G.M., Lagudah, E.S. 2005. D genome of wheat- 60 years on from Kihara, Sears and McFadden, pp. 205-220. In: Tsunewaki Koichiro (ed.), Frontiers of Wheat Bioscience:Memorial Issue, Wheat Information Service No. 100.  Kihara Memorial Foundationfor the Advancement of Life Sciences, Yokohama, Japan.
van Ginkel, M. And Ogbonnaya, F. 2007. Novel genetic diversity from synthetic wheats in breeding cultivars for changing production conditions. Field Crops Research 104:86–94. doi:10.1016/j.fcr.2007.02.005.