Background – Tef is an important cereal crop in Ethiopia,where the area under tef cultivation is overone million hectares of land each year. During the 1994/95 crop season, for instance, tef accounted for 32% of the land under cereal cultivation in Ethiopia (Ketema 1997). While tef is resistant to a number of abiotic stresses such as drought and heat, its optimal productivity (disease resistance and grain yield) is reached at an altitude of 1800-2100 m, annual rainfall of 750-850 mm, growing season rainfall of 450-550 mm, and a temperature range of 10 C-27 C (50 F-80.6 F) (Ketema 1997).

Tef’s importance as a crop in Ethiopia stems from its high nutritional value. The amino acid composition of tef is excellent, its lysine contentis higher than that of all cereals except rice and oats, it has good mineral content andits straw is nutritious for livestock.

The fact that several putative wild tef progenitor speciesof Eragrostis occur in Ethiopia, coupled with the observation that genetic diversity for tef exists nowhere in the world outside of Ethiopia, have led to the conclusion that Ethiopia represents both the center of origin (domestication) and diversity for tef (Vavilov 1951). It is interesting to note, then, that despite the high nutritional content of tef and its broad environmental tolerance, its cultivation has not spread substantially outside of Ethiopia in the time since its initial domestication prior to 4000 BC (Ponti 1978).

The limited range of tef cultivation outside of Ethiopia is likely the result of many factors, but one significant contributing factor may be the limited productivity (i.e., grain yield) of tef outside its optimal moisture and temperature range (note that it is most productive at higher elevations). This potential limitation to realized tef usage sets the stage for the case study presented here.

References Cited:

Ponti, J.A. 1978. The systematics of Eragrostis tef (Graminae) and related species. PhD

Thesis, University of London, London, UK.

Seyfu Ketema. 1997. Tef. Eragrostis tef (Zucc.) Trotter. Promoting the conservation and

use of underutilized and neglected crops. 12. Institute of Plant Genetics and Crop Plant

Research, Gatersleben/International Plant Genetic Resources Institute, Rome, Italy

Vavilov, N.I. 1951. The Origin, Variation, Immunity, and Breeding of Cultivated Plants

[translated from the Russian by K.S. Chester]. The Ronald Press Co., New York.

Case Study – As a rural development worker in a northern Ethiopian highland village, you are concerned by a trend you have observed over the past few years in your local community: rains have become less frequent and somewhat unpredictable, and temperatures, on average, have been slightly higher than normal. As a result, the amount of grain produced by the local tef crop has been reduced significantly enough to warrant some concern, as this crop represents a major protein source for your village as well as the surrounding communities.

While on your bi-annual trip to Addis Ababa, you meet up with your friend who works in the University there and has just returned from a sabbatical at the International Plant Genetics Resources Institute. You describe the situation to her, and you both agree that with global climate change becoming more and more of a reality, the trend you have been witnessing may be part of a more permanent emerging temperature and rainfall pattern.

Since your village, at 1500 m, is already at the lower end of the optimal elevation range for tef, it may not be possible to increase the grain yield by introducing a different tef variety. Your friend suggests that it may be possible to genetically manipulate tef in order to produce a variety that will be able to withstand higher temperatures and lower rainfall. Eragrostis, the genus to which tef belongs, has some close relatives that are desiccation tolerant and occur in very hot, dry areas in Tanzania and Kenya. At least one of these species has been studied in order to identify some of the major genes involved during its response to desiccation.

With these issues in mind, you and your friend begin discussing possible solutions to the problem of decreased tef grain yield:

Can you devise a possible strategy for a research program aimed at improving the performance of tef under novel (hotter/drier) climatic conditions?

  • What questions will you and your friend need to answer to address this problem?
  • What additional information (for instance, gene expression, gene family phylogeny, or biogeography) on tef (or other plants)will you need?
  • What types of resources might you need?