Principles of Plant Genetics and Breeding

Taxonomy
Kingdom Plantae
Subkingdom Tracheobionta
Superdivision Spermatophyta
Division Magnoliophyta
Class Lilliopsida
Subclass Commelinidae
Order Cyperales
Family Poaceae
Genus Sorghum Moench
Species Sorghum bicolor (L.) Moench
Subspecies Sorghum bicolor (L.) Moench
subsp. bicolor – grain sorghum
Economic importance
Sorghum was the world’s fourth most important crop in
1995, accounting for 4% of the total cereal production,
and a total harvest of 53 million metric tons. Sorghum
and millet are two of the major world food crops that
originate from Africa. Even though sorghum has become
important in the agricultural production of developed
countries, it is still primarily a developing country crop,
with 90% of the world’s acreage found in Africa and Asia.
In the USA, 470,525,000 bushels were produced in
2000 on 9,195,000 acres (see Appendix 2 for conversion
rates of units). The leading producer was Kansas,
with 3,500,000 acres and a production of 188,800,000
bushels, followed by Texas with an average of 3,000,000
acres and a production of 143,350,000 bushels. Other
important producers were Nebraska, South Dakota,
Colorado, Oklahoma, Missouri, Louisiana, New Mexico,
and Arizona. The varieties grown in the US are primarily
(78%) for grain. However, sorgho (sweet sorghum)
is grown for forage, silage, and syrup (stalks crushed).
The important sorgho states are Alabama, Mississippi,
Georgia, Tennessee, and Iowa. Dual purpose cultivars
30
Breeding sorghum
(grain and forage) are produced in states such as Texas,
Kansas, Nebraska, and Oklahoma.
On the world scene, sorghum is produced principally
in Africa, Asia, the Americas, and Australia. Important
producers in Africa include Nigeria, Sudan, Burkina Faso,
Cameroon, Chad, Mali, and Rwanda. About 74% of
sorghum produced in Africa is used for food. Most
developing countries use sorghum for food, unlike the
USA where sorghum is mainly grown for feed. Even
though most of the acreage for sorghum occurs in developing
countries, the US leads the world in production,
followed by India, Nigeria, China, Mexico, and Sudan.
Origin and history
Sorghum originated in northeastern Africa (Ethiopia,
Sudan, East Africa), where the greatest diversity of both
wild and cultivated species occurs. It was domesticated
in Ethiopia and parts of Congo between 5,000 and
7,000 ad with secondary centers of origin in India,
Sudan, and Nigeria. It moved into East Africa from
Ethiopia around 200 ad or earlier. It was distributed
along trade and shipping routes throughout Africa, and
through the Middle East to India at least 3,000 years
ago. Sorghum was taken to India from eastern Africa
during the first millennium bc. It arrived in China along
the silk route. It was introduced into the Americas as
guinea corn from West Africa through the slave trade, at
around the middle of the 19th century.
History of breeding in the USA
Concerned about the narrow genetic base of germplasm
available to US breeders, J. C. Stephens and J. R.
Quinby embarked upon a project to convert the tall, late
maturing, tropical accessions in the world collection to