Author
|
Submitted to: African Crop Science Journal
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/30/1995 Publication Date: N/A Citation: N/A Interpretive Summary: Sorghum is the fifth most important cereal crop in the world after wheat, rice, maize, and barley. Because of its importance, biotechnological tools have been used to manipulate and transform sorghum with unique genes normally not present within the species. The biotechnology and biosafety risk assessment in an African perspective workshop was convened in Nairobi, Kenya, to discuss the possible risks of introducing such sorghums into its place of origin. Given the fact that the four races of S. bicolor subspecies verticilliflorum, the annual wild sorghums, are so closely related, one can assume that these races and their distribution were greatly impacted upon by the four major evolutionary forces that influence the genetic processes of evolution: selection, mutation, random genetic drift, and migration. Humans continue to play a vital role in the evolution of cultivated sorghums and plant breeders have pushed the crop to higher levels and yield potential through continued selection and migration of genes. Biotechnology has become another tool by which to continue the process of selection and should assist plant breeders and scientists in the development, with minimal environmental impacts, of improved sorghums for human and animal consumption. Technical Abstract: Sorghum [Sorghum bicolor (L.) Moench.], family Gramineae, tribe Andropogeneae evolved and slowly spread primarily within the confines of the African subcontinent. From the four major forces of evolution: selection, mutation, random genetic drift, and migration, arose the wild representatives of S. bicolor subspecies verticilliflorum that are still present today. Though humans appeared on the scene about 2 million years ago, their role in the evolution of sorghum was probably limited to that of a physical agent of dispersal and occasionally an agent of selection. The cultivated sorghums of today are a complex and important crop and truly one of the great cereals of the world. Until approximately 10,000 years ago, the crop developed and evolved within the confines of a natural setting in which the four major forces of evolution played equally important roles. As humans began the process of agriculture, unconscious and conscious selection and migration became dominant players in shaping the history and dispersal of the crop, for it is not until the act of domestication (an integral part of the agricultural process) that we see the development of cultivated and highly complex forms of sorghum. Humans continue to play a vital role in the evolution of cultivated sorghums and plant breeders have pushed the crop to higher levels and yield potential through continued selection and migration genes. |
