Wild Sorghums—Their Potential Use in Crop Improvement

Abstract

Wild relatives of crops, sorghum being no exception, continue to play a key role in the development of high performing cultivars. Among the 22 species comprising this highly variable genus, only one, Sorghum bicolor, is commercially cultivated for food, feed and bioenergy production. The wild sorghums thus offer opportunities for further genetic enhancement of this crop. Profi table utilization of wild species however demands an inter-disciplinary, multi-pronged approach to increase the probability of achieving the desired genetic improvement. To this end, this chapter presents a review of the current knowledge on (1) biosystematic aspects such as botany, taxonomy and classifi cation, (2) domestication and evolution, including centers of diversity, genetic diversity, chromosome homologies and species/ phylogenetic relationships, (3) genetic resources, genepools and conservation perspectives including collections and preservation of germplasm, (4) utilization aspects including the specifi c potential of the wild species in crop improvement with reference to insect and disease resistance, yield, grain quality, ecological adaptation, allopatric resistance, and (5) strategies to maximize utilization of wild germplasm resources including direct hybridization, reproductive barriers and their circumvention, chromosome and physiological manipulation, the gaps between hybridization and utilization and molecular interventions. Recent advancements in biotechnology, in particular, are expected to increase the effi ciency and range of use of these wild sorghum species.