Chapter 2 - Origin, Domestication and Diffusion of Sorghum bicolor

Abstract

Sorghum is an ancient crop of African origin and especially important in the semiarid tropics of Africa and South Asia, with significant production also in China, Southeast Asia, and the Americas. Questions regarding the time and place of its origin and domestication have been long deliberated on and debated. The earliest evidence of wild sorghums comes from hunter-gatherers in the Sahara dating to about 8000 BC, but the earliest known domesticated sorghum until now dated to 2000–1700 BC was reported from Late Harappan India where it is not a native crop. Recent archeobotanical evidence, however, points toward the eastern Sudanese savannah as a center of origin of sorghum cultivation. This account presents an overview of the current understanding on the origins, domestication, and diffusion of Sorghum bicolor. Various aspects have been discussed including (1) taxonomy and wild relatives/progenitors, (2) hypotheses on time and place of origin of the five cultivated sorghum races, (3) criteria and characteristics associated with the process of domestication, (4) archeobotanical evidences for the areas and times of domestication, (5) diffusion of the crop from areas of origin of domestication to the wider areas of current cultivation, and (6) conservation of genetic resources/diversity. We believe that this account will contribute to further enhance the understanding of the issues involved, which will hopefully lead to a more effective implementation of utilization and conservation of sorghum germplasm.