Sorghum is a tropical grass species originally domesticated as a grain crop in sub-Saharan Africa about 8,000 years ago.
Grain sorghum is most closely related to the perennial species Sorghum halepense, or Johnsongrass. This presents The Land Institute an opportunity to develop a perennial variety by hybridizing annual sorghum, Sorghum bicolor, with S. halepense.
Why Perennial Sorghum?
- In much of Africa and South Asia, sorghum is consumed in flat breads, porridges, couscous, beer, and other products. It can be used to make tortillas as well. In the United States, sorghum flour is increasingly being used in all kinds of processed foods, similarly to corn meal or flour.
- Although it could take anywhere from 10 to 30 years to have a commercially viable perennial sorghum variety, there are good signs that our goal is feasible and that this work should continue. Each year since 2009, we have selected perennial lines with successively higher yields and more crop-like plant traits and have seen progress in key traits like perenniality and grain production. These are both complex traits governed by large complexes of genes, so progress in combining those traits is gradual year by year.
- Early results of ecological adaptation to tropical and subtropical climates are promising, suggesting that it may be worthwhile to cross regionally adapted annual varieties from different parts of Africa with perennial sorghum.
- Breeding perennial sorghum in Kansas means selecting perennial plants that can endure very cold winters. Our populations are also being evaluated at Texas A&M University, the University of Georgia, and Bologna, Italy, where winters are milder, as well as in Mali, Uganda, the Republic of South Africa, China’s Yunnan Province, and the Indonesian island of Bali, to evaluate for ecological adaptation in tropical and semitropical climates.
The Land Institute, working with Kansas State University, began making crosses between annual sorghum and S. halepense in the 1980s. The long-term goal was to develop populations of perennial sorghum that could produce repeated, sufficient grain harvests without resowing. This new crop would fit into food-producing ecosystems.
In 1994, Land Institute scientists Jon Piper and Peter Kulakow published a study of S. bicolor x S. halepense hybrid populations, concluding that perennial grain sorghum was a feasible goal.
However, the full-fledged breeding program aimed at developing perennial sorghum started almost a decade later; Lead Researcher Stan Cox joined The Land Institute staff in 2000 and in 2003, had made initial crosses between hardy perennial plants drawn from Piper and Kulakow’s populations and grain sorghum parental lines developed at universities in the United States.
In 2016 Land Institute researchers published a study based on field experiments done in 2011-13 showing that selection during the first seven years of the program (2003-09) had produced perennial lines with almost triple the grain yield of the perennial parents we had started with in 2002. That was a yield increase of about 27 percent per year.
In 2018 the Land Institute researchers published the study, “High proportion of diploid hybrids produced by interspecific diploid× tetraploid Sorghum hybridization” in the journal Genetic Resources and Crop Evolution.
The Land Institute and its research partners are currently selecting for perennial growth habit and grain productivity in diverse environments in the United States and several African countries.
- Continued breeding of perennial sorghum and selecting perennial plants that can endure very cold winters.
- Through global collaborations, evaluation for ecological adaptation in tropical and semitropical climates.
- The long-term goal is to develop a commercially viable perennial sorghum variety with populations of perennial sorghum that could produce repeated, sufficient grain harvests without resowing.
Agricultural Research Council, South Africa
ICRISAT, Bamako, Mali
ICRISAT, New Delhi, India
Jimma University, Ethiopia
Makerere University, Kampala, Uganda
Michigan State University, East Lansing, Michigan
Texas A&M, College Station, Texas
University of Georgia, Athens, Georgia
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At The Land Institute, perennial sorghum research technician, Megan Gladbach, takes us behind the scenes…
Related Scientific Publications
Detection of Quantitative Trait Loci Regulating Seed Yield Potential in Two Interspecific S. bicolor2 X S. halepense Subpopulations
Abstract Perennial sorghum cropping offers substantial economic and ecological benefits, conserving fuel, water, and soil. To be perennial in temperate climates, a sorghum plant must over-winter and produce new growth…
Despite a “ploidy barrier,” interspecific crosses to wild and/or cultivated sorghum (Sorghum bicolor, 2n = 2x = 20) may have aided the spread across six continents of Sorghum halepense, also exemplifying…