Search

The emerging oilseed crop Sesamum indicum, also known as the queen of oilseeds, is being grown globally for its oil content for medicinal and nutritional values. One of the key challenges of sesame cultivation is its low productivity. In the present study, sodium azide (NaN3) was used as a chemical mutagen. The aim of this study was to examine the effect of NaN3 on quantitative and qualitative stem traits in the M2 generation of Ethiopian sesame (Sesamum indicum L.) genotypes. Seeds of fourteen sesame genotypes were used in this study and germinated and grown under greenhouse conditions. Different qualitative and quantitative data were collected and analyzed. Traits such as plant height, ground distance to first distance, and internode length were significantly affected by NaN3 treatment. The highest plant height was recorded in the control on Humera 1 and Baha Necho genotypes, while the lowest was observed on Setit 2 and Hirhir treated with the chemical. The highest ground distance to the first branch was observed in Gumero, while the least ground distance was recorded in Setit 1 in the treated and control genotypes, respectively. The best internode length was recorded on Setit 2 and ADI in the control, while the lowest internode length was observed in Setit 1 genotype treated with sodium azide. Genotypes such as ACC44, ADI, Baha Necho, Borkena, Gonder 1, and Setit 1 treated with NaN3 have showed glabrous type of stem hairiness. All the fourteen genotypes (both treated and control) were clustered into four groups. In conclusion, we observed a highly significant variation among the genotypes due the effect of the chemical and genotypes themselves. Hence, this report would create more genetic diversity for further sesame genetic research improvements.

The study aimed at evaluating the influence of environment on sweetpotato stability and identifying superior genotype(s) with high yield stability in the farmers’ field conditions. Six sweetpotato genotypes were evaluated for two years in ‘meher’ season (July- December), 2014 and 2016; four of the six genotypes were assessed for three years in the ‘meher’ season, 2012, 2014, and 2016. Planting was done in three replications in RCBD in three unique agro-ecologies: Endayesus-dry highland, Fachagama-dry lowland, Rarhe-moist lowland. Genotypes genetic merits were predicted using BLUP. The AMMI and GGE were used to test the genotypes stability. The ANOVA for AMMI model showed high significant difference (P0.01) for genotypes, environments, seasons, and the interactions. Environment (41.67%) and the genotype main effect (35.71%) contributed largely to the cumulative variance for three years testing of four genotypes and two years testing of six genotypes, respectively. Berkume (42.44 t/ha), Tulla (33.92 t/ha) and Kulfo (33.67 t/ha) were superior for total storage root tuber yield (TTRY).Both the AMMI and GGE biplot predicted Tulla and Kulfo as ideal genotypes with dynamic stability; Berkume with static stability to Rarhe. The environment main effect had significant influence in determining how genotypes expressed their genetic potentials and stability as shown by the AMMI model and GGE biplot. The AMMI model partitioned the studied agro-ecologies of the Tigray region into two mega sweetpotato growing environments; the dry high/lowland in one environment and the moist lowland in another, completely different, but with high potentials for sweetpotato production.

This study was conducted to develop an efficient regeneration protocol used for sesame genetic transformation. Published regeneration methods using 6-benzylaminopurine (BAP), indol-3-butyric acid (IBA), and α-naphthaleneacetic acid (NAA) were used in this experiment. Cotyledon explants of 14 Ethiopian genotypes collected from Humera Agricultural Research Center (HuARC) were used. Optimized culture conditions were used to investigate the regeneration response of different genotypes. Significant interactions between hormone treatments, MS media, and genotypes for shoot and root regeneration were recorded. Results showed that culture of cotyledons were developed and used as a source of explants for shoot regeneration. The highest shoot number, leaf number, and shoot length were recorded on explants cultured on 1.00 mg·L−1 BAP + 1.00 mg·L−1 NAA in Hirhir and Aberghele, 0.75 mg·L−1 BAP + 1.00 mg·L−1 NAA in Baha Zeyit, and 1.0 mg·L−1 BAP + 1.00 mg·L−1 NAA in Humera 1, respectively. The lowest shoot number, leaf number, and shoot length were observed on explants cultured on the control in Gondar 1, Borkana, and Baha Necho, Borkana and Beha Necho, and Baha Necho, respectively. Genotypes with well-developed shoots were transferred to root induction media. Under rooting media, the best mean, root number, and root length were observed in Aberghele and ACC44 at 0.1 mg·L−1 IBA and 0.2 mg·L−1 NAA, respectively. Standardizing genotypes trait data to mean 0 and unity variance has helped to group 14 genotypes into four distinct clusters. Hirhir, Abeghele, Baha Zeyit, and Humera 1 were the best genotypes. These findings lay ground to Ethiopian sesame to do further genetic transformation aiming at improving the crop.

The experiment was conducted in Northern Ethiopia from 2011-2013 under rain fed conditions in a total of seven environments vis. E1, E2, E3, E4, E5, E6 and E7. The objective of the study was to evaluate the adaptability and stability of sesame genotypes across environments. 13 sesame genotypes were evaluated and the experiment was laid out in a Randomized Complete Block Design with three replications. The average grain yield of the genotypes was 742.9 Kg/ha with the outstanding genotypes being G4 (926.8 kg/ha), G1 (895.1 kg/ha) and G12 (832.7 kg/ha) respectively, and low the yielding genotype was G9 (614.3 kg/ha). The combined ANOVA for grain yield showed significant effects of the genotypes, environments and genotype x environment interaction. According to the additive main effect and multiplicative interaction bi-plot (AMMI bi-plot) and Genotype x Environment interaction bi-plot (GGE bi-plot) G12 was the most stable, and G7, G8 and G9 were the unstable genotypes. Furthermore, the Genotype main effects and GGE bi-plot showed E5 as the most discriminating and representative environment. The GGE bi-plot also identified two different growing environments, the first environment containing E4 and E6 (in the Dansha area) with the wining genotype G1; and the second environment encompassing E1, E2, E3, E5 and E7 (in the Humera, Dansha and Sheraro areas) with winning genotype of G4. Key words: AMMI bi-plot, environment, GEI, GGE bi-plot.

A field experiment was conducted to investigate the influence of different nitrogen and phosphorus fertilizer levels on dekoko (Pisum sativum var.abyssinicum A.Braun) yield and yield components as well as to establish the net benefit at each fertilizer levels. The Experiment was conducted at Mekelle university Endayesus campus in Tigray, Northern Ethiopia in 2013/14. It was laid out in a randomized complete block design with four blocks. It comprises four nitrogen (N) and phosphorus (P) fertilizer treatments combinations. Viz., Control (N0P0), 30 kg N ha-1 and 30 kg P2O5 ha-1 (N1P1), 60 kg N ha-1 and 60 kg P2O5 ha-1(N2P2) and 90 kg N ha-1 and 90 kg P2O5 ha-1 (N3P3).The highest yield (2114.55 kg ha-1), biomass (5312.5 kg ha-1), nitrogen and phosphorus use efficiency (4.58 kg kg-¹) and maximum marginal rate of return (499%) were obtained when treated with N2P2. From the present results it could be concluded that 60 kg N ha-1 and 60 kg P2O5 ha-1 fertilizer rate would be optimum treatment combination for enhancing dekoko yield and yield components, NP use efficiency, and economic profitability. Therefore, application of 60 kg N ha-1 and 60 kg P2O5 ha-1 is recommended for better productivity and profitability of dekoko at low soil fertility levels.

Tigray (region) is one of the major finger millet growing regions in Ethiopia and an important site from an archeobotanical point of view. Three zones of Tigray (east, central and west) were identified as representative sites in the region and a total of 14 districts/ ‘Woreda’ were surveyed. Thirty-seven landraces/farmers’ varieties of finger millet were identified/recorded. Farmers in Tigray undertake pre and post harvest selection in finger millet and sometimes they also select seeds from storage based on a number of attributes. Farmers maintain diversity as a way to ensure harvest security or stability of production, to promote diversity of diet and income sources, minimize crop failure risk, reduce insect and disease incidences and ensure efficient use of labour. The traditional management of finger millet in the entire study area is generally found to be demand driven, showing the existence of potential sites for on-farm conservation. The high morphological diversity (H =0.76 ± 0.09) found in the gene bank collections of Tigrayan origin also reveals the importance of linking ex situ with in situ conservation activities. Furthermore, the enhancement and conservation significance of the crop is discussed.

Sorghum is an important crop for the south and central parts of Tigray Region of Ethiopia. To assess the level of sorghum diversity, two zones, namely South and Central Tigray were selected and eighteen villages in three woredas, Alamata, Raya-Azebo and Tanqua-Abergelle, were surveyed. A total of 93 randomly selected farmers were interviewed using a structured questionnaire that elicited information on socioeconomic aspects of households, sorghum plots, the number and types of farmers’ local varieties grown in the area, variety characteristics, seed exchange systems and seed flow together with selection criteria’s as well as seed selection process and management. A total of 165 collections belonging to 31 locally named sorghum varieties were retrieved and stored at Mekelle University. High diversity in terms of landrace richness were found the Alamata area (Margalef = 2.92; Menhinick = 1.66) followed by Raya-Azebo (Margalef = 2.61; Menhinick = 1.46) and Tanqua-Abergelle was found to be less diverse in terms of number of named varieties (Margalef = 1.40; Menhinick = 1.0). Diversity estimated based on evenness indices showed that Tanqua-Abergelle has the highest diversity (Shannon =0.86; Brillouin index = 0.86) followed by Raya-Azebo (Shannon =0.85; Brillouin index = 0.85). The lowest evenness was found in Alamata woreda (Shannon =0.77; Brillouin index = 0.77). Based on the varietal richness and use values, four sites (villages) that could serve as seed repositories were identified. The result of the econometric analysis indicated that a combination of factors, such as year of schooling, labour equivalence, tropical livestock unit, and number of parcels were the most important determinants that affect significantly the intra-specific diversity. The regression analysis indicates the positive linkage between land fragmentation and landrace richness. The increase in diversity over temporal scale of ten years found in this study revealed that the level of genetic erosion needs numerical evidence to substantiate. The socioeconomic factors that affect varietal diversity and possible conservation and incentive strategies are discussed. Key words: Sorghum, Diversity, Seed flow, Genetic erosion, Resilience