Genetic diversity in tef [Eragrostis tef (Zucc.) Trotter]

Tef [Eragrostis tef (Zucc.) Trotter] is a cereal crop resilient to adverse climatic and soil conditions, and possessing desirable storage properties. Although tef provides high quality food and grows under marginal conditions unsuitable for other cereals, it is considered to be an orphan crop because it has benefited little from genetic improvement. Hence, unlike other cereals such as maize and wheat, the productivity of tef is extremely low. In spite of the low productivity, tef is widely cultivated by over six million small-scale farmers in Ethiopia where it is annually grown on more than three million hectares of land, accounting for over 30% of the total cereal acreage. Tef, a tetraploid with 40 chromosomes (2n = 4x = 40), belongs to the family Poaceae and, together with finger millet (Eleusine coracana Gaerth.), to the subfamily Chloridoideae. It was originated and domesticated in Ethiopia. There are about 350 Eragrostis species of which E. tef is the only species cultivated for human consumption. At the present time, the gene bank in Ethiopia holds over five thousand tef accessions collected from geographical regions diverse in terms of climate and elevation. These germplasm accessions appear to have huge variability with regard to key agronomic and nutritional traits. In order to properly utilize the variability in developing new tef cultivars, various techniques have been implemented to catalog the extent and unravel the patterns of genetic diversity. In this review, we show some recent initiatives investigating the diversity of tef using genomics, transcriptomics and proteomics and discuss the prospect of these efforts in providing molecular resources that can aid modern tef breeding

Response of bread wheat to increasing mustard meal nitrogen application on pellic Vertisol and utric Nitosol

Mustard seed meal was evaluated on the field as source of nitrogen for bread wheat on Pellic Vertisol and Eutric Nitosol in a split plot design with three replications. Highly significant yield increases were obtained due to mustard meal nitrogen rates during all the experimental periods on the Vertisol. The increase in the grain yields of wheat was linearly related to the mustard meal nitrogen rates (r=0.98 and 0.96 for fresh and decayed meal, respectively) and varied from two to ten fold of the control. On the Nitosol, significant effect was obtained only in one crop season. Greenhouse experiment on the nitrogen uptake from the mustard meal using 15N showed significant difference on both soil types. On the Vertisol the per cent nitrogen derived from the meal and per cent nitrogen use efficiency varied from 18 to 40 and from 18 to 62%, respectively. On the Nitosol, these values varied from 25 to 71 and from 43 to 62%, respectively. Application and incorporation of the mustard seed meal into the soil 20B25 days before planting minimised the toxicity of the meal on seed germination and seedling growth. SINET: Ethiopian Journal of Science Vol. 23, No. 1 (June 2000), pp. 53-66 Key words/phrases: Eutric Nitosol, mustard seed meal, nitrogen use efficiency, Pellic Vertisol, whea