Sorghum, first grown more than 6,000 years ago in northeastern Africa, is a drought-resistant, hardy crop with numerous food, feed and fuel applications. Farmers in the southern plains of the United States have been growing this hardy cereal since the 1800s. Researchers recently released 40 varieties of early-flowering sorghum bred for use in cooler, more temperate areas. These early-flowering varieties of sorghum are critical for the spread of the crop to more new locations. When planted in areas with long days and cold soils, typical sorghum crops face difficulties.
Sorghum originates in the tropical areas of Africa—it does not like cool temperatures or the long days in temperate climates.—Robert Klein, a researcher at the USDA-ARS and Texas A&M University
As seasons change, the length of the day varies much more in temperate areas than in tropical regions. Sorghum needs day lengths of less than 12 hours and 20 minutes to flower. However, by the time days become short enough in late summer for sorghum crops to flower, it also becomes too cold for them to survive in temperate climates.
There is a great deal of naturally-occurring genetic diversity in the sorghum collection, and our research program exists to provide that genetic diversity to seed companies and eventually to the consumer.—Robert Klein
The genetic diversity of sorghum and other plants is often preserved in germplasm collections. Researchers define germplasm as a living genetic resource such as seed or tissue.
This genetic diversity is key. Diseases or pests can spread from one region to another and destroy entire crops. To prevent this, researchers can search germplasm collections and breed crop varieties with natural resistance.
Forty sources of late-maturing sorghum [Sorghum bicolor (L.) Moench] germplasm were converted to early-maturing, dwarf-height BC1F3 families and released by the National Sorghum Foundation, the United Sorghum Checkoff Program, the USDA-ARS, and NuSeed/MMR Genetics.
The conversion was accomplished by crossing late-maturing tropical accessions to inbred BTx406 in a short-day nursery with selection of early-maturing, short genotypes within F2 segregating populations in a long-day nursery.
Klein, R. R.; Miller, F. R.; Bean, S.; Klein, P. E. (2016) “Registration of 40 Converted Germplasm Sources from the Reinstated Sorghum Conversion Program” Journal of Plant Registrations Vol. 10 no. 1 doi: 10.3198/jpr2015.05.0034crg