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Seeds of Trade

 
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Product: Sorghum

Other products:  
   Sorghum belongs to these categories: Animal fodder, Food crops
   and originated in Africa

 SUMMARY
 WILD RELATIVES
 ORIGINS
 EARLY USES
 TRANSFER AND SPREAD
 AGRICULTURE
 MODERN CONTEXT
  POST HARVEST


Wild relatives

Sorghum bicolor L. (cultivated sorghum) is a staple in the semi-arid tropics of Africa and Asia. The genus Sorghum has 25 species, distributed in Africa, Asia and Australia, and is closely related to maize (Zea mays L.) and sugar cane (Saccharum officinarum L.). The genus is split into five sections, but the relationships between these are not clear and the only group that appears to be natural is section Eusorghum, generally considered to be the most evolutionarily advanced and containing both the cultivated species and their wild ancestors.

The progenitor of cultivated sorghum is Sorghum arundinaceum (Desv.) Stapf. ex Prain, an annual wild species from the humid tropics of West and Central Africa. Some have suggested that Sorghum halepense (L.) Pers. of Pakistan and India and the perennial Sorghum propinquum (Kunth) Hitchc. from South-East Asia were ancestral progenitors of the cultivated sorghums. Using DNA sequencing and analyses of morphology botanists have shown that, in fact, S. propinquum is a rhizomatous derivative of Sorghum bicolor and that Sorghum halepense originated from a chromosome doubling and hybridisation event between Sorghum arundinaceum and Sorghum propinquum. The domesticated sorghums consist of a complex of intergrading forms of wild, weedy and strictly cultivated forms. The variation in morphology is immense and interfertility of species coupled with extensive hybridisation means that sorting out the origins and relationships of the cultivated forms is not easy.

Older taxonomic classifications of the cultivated sorghums recognise the cultivated types (now recognised as cultivars or genetic races) as subspecies; the five principal cultivated types of sorghum are 'Bicolor' from North Africa, 'Guinea' from West Africa, 'Durra' and 'Caudatum' from north-east Africa and also found in India, and 'Kafir' from the Nile region.