Kebebew Assefa

Global warming has intensified drought episodes worldwide, with Africa experiencing pronounced impacts due to its reliance on rain-fed agriculture. This study investigated drought responses in tef (Eragrostis tef [Zucc.] Trotter) with the aim of identifying drought-tolerant genotypes and their underlying adaptive mechanisms. Tef is more resilient to drought than wheat, maize and rice but substantially affected by prolonged moisture scarcity. Twenty tef genotypes were evaluated under optimal and drought-stress conditions. Drought stress at the booting stage, followed by rehydration, significantly reduced soil and leaf water content, resulting in delayed maturity and substantial effect on agronomic and physiological traits. However, pronounced genotypic variation was observed. Drought-tolerant genotypes (For e.g RIL 44) exhibited smaller reductions in agronomic traits and demonstrated adaptive strategies, including early maturity and rapid recovery of normalized difference vegetation index and chlorophyll content (determined by SPAD), which collectively contributed to the maintenance of grain yield and shoot biomass under drought conditions. However, higher grain yield was not always associated with larger biomass, likely due to genotypic differences in biomass partitioning efficiency. Furthermore, genotypic differences were observed in responses to dehydration alone, and to rehydration following dehydration, indicating that most genotypes possess specific adaptations to either stress phase. These findings highlight the importance of evaluating combined drought and recovery responses and suggest that integrated stress screening could improve the identification of genotypes and mechanisms that enhance resilience to climate variability, particularly under conditions of erratic and reduced rainfall. We propose that root architectural studies conducted under field conditions across multiple environments and growing seasons would enhance the practical applicability of these findings for the development of drought-resilient tef genotypes.

Tef ( Eragrostis tef ) is an indigenous African cereal that is gaining global attention as a gluten-free “superfood” with high protein, mineral, and fibre contents. However, tef yields are limited by lodging and by losses during harvest owing its small grain size (150x lighter than wheat). Breeders must also consider a strong cultural preference for white-grained over brown-grained varieties. Tef is relatively understudied with limited “omics” resources. Here, we resequenced 220 tef accessions from an Ethiopian diversity collection and also conducted multi-locational phenotyping for 25 agronomic and grain traits. Grain metabolome profiling revealed differential accumulation of fatty acids and flavonoids between white and brown grains. We conducted k -mer and SNP-based genome wide association and uncovered novel marker-trait associations. A significant 70 kb peak for panicle morphology contained the tef orthologue of rice qSH1 , a transcription factor regulating inflorescence morphology in cereals. We also observed a previously unknown relationship between grain size, colour, and fatty acids. These traits were highly associated with retrotransposon insertions in homoeologues of TRANSPARENT TESTA 2 , a known regulator of grain colour. Our study provides valuable resources for tef research and breeding, facilitating the development of improved cultivars with desirable agronomic and nutritional properties.

Tef, Eragrostis tef (Zucc.) Trotter is the main crop grown in Ethiopia. However, its productivity remains low compared to its potential yield. A multi-location trial was conducted to evaluate selected best-performing lines from previous trials in terms of stability and yield coupled with farmers’ opinions and preferences, aiming to identify superior lines. A total of twenty tef genotypes, including a standard and a local check were field evaluated using RCBD with four replications. The lines were grown in 4 m² plots across eight different locations in Ethiopia during the 2018/19 and 2019/20 cropping seasons. Additionally, an on-farm participatory variety evaluation involving 198 participants, comprising farmers and agricultural experts, was conducted during the 2019 cropping season. Phenological and agromorphological traits were collected and subjected to statistical analysis to identify the best genotypes. The pooled analysis of variance revealed significant variation (at the 0.01% level) among genotypes, locations, and years for all traits except grain yield and days to maturity. While some genotypes produced comparable grain yields, none surpassed the standard check variety Negus. Additionally, Participatory variety selection was conducted during the crop maturity stage using the direct-matrix ranking method. Farmers sets their own selection criteria, these are crop stand, tillering capacity, panicle weight, lodging tolerance, culm strength, and pest infestation or infection. Based on their evaluation, the genotypes DZ-01-974 X GA-10-3 RIL 51, DZ-01-974 X GA-10-3 RIL 47 and DZ-01-974 X GA-10-3 RIL 68 were identified as farmers preferred varieties from direct matrix ranking evaluations and chosen for their performance in the field. Thus, this study highlights the feasibility of participatory variety selection in gaining insights into farmer’s perceptions, preferences, strengths and weaknesses of tef genotypes.

Summary: Tef is a staple food and a valuable cash crop for millions of people in Ethiopia. Lodging is a major limitation to tef production, and for decades, the development of lodging resistant varieties proved difficult with conventional breeding approaches. We used CRISPR/Cas9 to introduce knockout mutations in the tef orthologue of the rice SEMIDWARF‐1 (SD‐1) gene to confer semidwarfism and ultimately lodging resistance. High frequency recovery of transgenic and SD‐1 edited tef lines was achieved in two tef cultivars by Agrobacterium‐mediated delivery into young leaf explants of gene editing reagents along with transformation and regeneration enhancing morphogenic genes, BABY BOOM (BBM) and WUSCHEL2 (WUS2). All of the 23 lines analyzed by next‐generation sequencing had at least two or more alleles of SD‐1 mutated. Of these, 83% had tetra‐allelic frameshift mutations in the SD‐1 gene in primary tef regenerants, which were inherited in subsequent generations. Phenotypic data generated on T₁ and T₂ generations revealed that the sd‐1 lines have reduced culm and internode lengths with no reduction in either panicle or peduncle lengths. These characteristics are comparable with rice sd‐1 plants. Measurements of lodging, in greenhouse‐grown plants, showed that sd‐1 lines have significantly higher resistance to lodging at the heading stage compared with the controls. This is the first demonstration of the feasibility of high frequency genetic transformation and CRISPR/Cas9‐mediated genome editing in this highly valuable but neglected crop. The findings reported here highlight the potential of genome editing for the improvement of lodging resistance and other important traits in tef.

Many regions around the world are experiencing an increase in climate-related shocks, such as drought. This poses serious threats to farming activities and has major implications for sustaining rural livelihoods and food security. Farmers’ ability to respond to and withstand the increasing incidence of drought events needs to be strengthened and their resilience enhanced. Implementation of measures to enhance resilience is determined by decisions of farmers and it is important to understand the reasons behind their behavior. We assessed the viability of measures to enhance resilience of farmers to drought, by developing a general framework that covers economic-technical and psychological-cognitive aspects, here summarized under the terms (1) motivation and (2) feasibility. The conceptual framework was applied to cocoa farmers in Ghana and tef farmers in Ethiopia by using questionnaire-based surveys. A portfolio of five specific measures to build resilience (i.e., irrigation, shade trees, fire belts, bookkeeping, mulching, early mature varieties, weather forecast, reduced tillage, improved harvesting) in each country was evaluated with a closed-ended questionnaire that covered the various aspects of motivation and feasibility whereby farmers were asked to (dis)agree on a 5-point Likert scale. The results show that if the motivation mean score is increased by 0.1 units, the probability of implementation increases by 16.9% in Ghana and by 7.7% in Ethiopia. If the feasibility mean score is increased by 0.1 units, the probability of implementation increases by 24.9% in Ghana and by 11.9% in Ethiopia. We can conclude that motivation and feasibility matter, and we improve our understanding of measure implementation if we include both feasibility and motivation into viability assessments.

Tef is a resilient crop from the Horn of Africa with significant importance in food and nutrition security, and currently gaining global popularity as health and performance food.

Teff is the only cultivated cereal crop from the genus Eragrostis and it is the major staple food of Ethiopians. In Ethiopia, the quality of teff and its market price are primarily determined by its grain color. The objective of this study was to evaluate the effects of soil physicochemical characteristics across multiple locations in the two main teff growing regions of Amhara and Oromia states in Ethiopia on teff grain color and nutritional quality of a single variety. Grain and soil samples were collected from 24 field sites cultivated with the popular teff variety ‘Quncho’ (DZ-Cr-387/RIL-355). The teff grain samples collected from the 24 locations were evaluated for grain color, proximate composition, amino acid composition, and grain mineral concentration and the soil samples were analyzed for their physicochemical properties. Sample location means were considered different p < 0.05. Teff grain color indices of hue (H), saturation (S), and brightness (V), grain proximate composition, amino acid composition, and mineral concentration differed among locations (p < 0.05). There were significant negative correlations between grain S color value and soil pH, SOC, Ca, Mg, S, and Na. Soils with greater pH, SOC, Ca, Mg, and S generally had lower S values and thus, whiter color teff grains. There were considerable variations in the measured parameters for soil and teff grain physicochemical properties. The results indicated an opportunity for management interventions necessary to obtain uniformity in grain color and chemical composition for the same variety of teff grown in the two major regions in Ethiopia.

This study was aimed to determine gene action for grain yield and yield‐related traits of newly developed tef populations under drought‐stressed and nonstressed conditions to improve drought tolerance. Ten crosses, along with the parents, were evaluated in the F₂ generation under drought‐stressed conditions at Hastebo and Adigdad sites in 2015 and Dura site in 2016 and under nonstressed conditions at Dura site in 2016. Additive gene action predominantly controlled the inheritance of the grain yield and majority of the yield‐related traits under drought‐stressed and nonstressed conditions. Under both test conditions, the genotypes DZ‐Cr‐387 and 9415 were the best general combiners for increased grain yield and morphological traits. Conversely, genotype 222076 was the best general combiner for reduced maturity period only. The selected parents are novel genetic materials for tef breeding programmes to improve grain yield and morphological traits with reduced days to maturity for drought tolerance breeding. The family of the cross DZ‐Cr‐387 × 222076 was selected for high grain yield and early maturity in both the drought‐stressed and nonstressed environments.

Indigenous crops also known as orphan crops are key contributors to food security, which is becoming increasingly vulnerable with the current trend of population growth and climate change. They have the major advantage that they fit well into the general socio-economic and ecological context of developing world agriculture. However, most indigenous crops did not benefit from the Green Revolution, which dramatically increased the yield of major crops such as wheat and rice. Here, we describe the Tef Improvement Project, which employs both conventional- and molecular-breeding techniques to improve tef—an orphan crop important to the food security in the Horn of Africa, a region of the world with recurring devastating famines. We have established an efficient pipeline to bring improved tef lines from the laboratory to the farmers of Ethiopia. Of critical importance to the long-term success of this project is the cooperation among participants in Ethiopia and Switzerland, including donors, policy makers, research institutions, and farmers. Together, European and African scientists have developed a pipeline using breeding and genomic tools to improve the orphan crop tef and bring new cultivars to the farmers in Ethiopia. We highlight a new variety, Tesfa, developed in this pipeline and possessing a novel and desirable combination of traits. Tesfa’s recent approval for release illustrates the success of the project and marks a milestone as it is the first variety (of many in the pipeline) to be released.