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Abstract Fermentation of cereal-made dough was the primary Ethiopian food for many years. Sourdough is believed to have many beneficial fermenting micro-floras depending on the source of dough and environmental conditions. The study aimed to isolate and characterize yeasts from fermenting cereal dough and evaluate their leavening potential for wheat dough. Morphological and biochemical characterizations such as sugar fermentation, glucose tolerance test, growth at different pH and temperatures, and agitation effect were employed to select potent yeasts. Accordingly, 16 potential yeast isolates were selected and subjected to further analysis. Finally, the yeasts were tested and compared for their leavening activity on the wheat dough at 37 °C and room temperature. Results revealed marvelous CO2 producer mesophile yeasts that degrade various sugars and tolerate up to 60% glucose concentration. The overall characterization assigned all the yeast isolates to the genus Saccharomyces and the Candida humilis. ANOVA showed that leavening activity by the yeast isolates was statistically higher at 37 °C compared to room temperature. The highest dough volume (6.2 mL) was recorded from Wh17, Wh5, and Ba12 isolates. Sor9 isolates were among the yeast that raised a minimum dough volume (0.7 mL). In contrast to commercial yeasts, the present study detected exceptional yeasts that matured within 24 h. Therefore, the discovered potential yeasts can be used for leavening dough in a short fermentation time and add aroma to baked products, making them a candidate in the baking industry. It could also be cost-effective as it could reduce media consumption and electricity utilization.

Sesame is an important oilseed crop cultivated in Ethiopia as a cash crop for small holder farmers. However, low yield is one of the main constraints of its cultivation. Boosting and sustaining production of sesame is thus timely to achieve the global oil demand. This study was, therefore, aimed at identifying mutant genotypes targeted to produce better agronomic traits of M2 lines on fourteen Ethiopian sesame genotypes through seed treatment with chemical mutagens. EMS was used as a chemical mutagen to treat the fourteen sesame genotypes. Quantitative and qualitative data were recorded and analyzed using analysis of variance with GenStat 16 software. Post-ANOVA mean comparisons were made using Duncan's Multiple Range Test (p≤ 0.01). Statistically significant phenotypic changes were observed in both quantitative and qualitative agronomic traits of the M2 lines. All mutant genotypes generated by EMS treatment showed a highly significant variation for the measured quantitative traits, except for the traits LBL and LTL. On the other hand, EMS-treated genotypes showed a significant change for the qualitative traits, except for PGT, BP, SSCS, LC, LH and LA traits. Mutated Baha Necho, Setit 3, and Zeri Tesfay showed the most promising changes in desirable agronomic traits. To the best of our knowledge, this study represents the first report on the treatment of sesame seeds with EMS to generate desirable agronomic traits in Ethiopian sesame genotypes. These findings would deliver an insight into the genetic characteristics and variability of important sesame agronomic traits. Besides, the findings set up a foundation for future genomic studies in sesame agronomic traits, which would serve as genetic resources for sesame improvement.

This study aimed at investigating the effects of sodium azide (NaN3) on quantitative and qualitative capsule traits in M2 generation of 14 Ethiopian sesame genotypes collected from Humera Agricultural Research Center (HuARC), Tigrai. Both the treatment and control seeds were sown in well-prepared beds in greenhouse to develop M2 plants. Data on quantitative and qualitative traits were collected and analyzed using GenStat 16 software. Results showed significant differences among the M2 seeds treated with 0.75% NaN3. The highest mean number of capsules per plant was recorded in ACC44 and Baha Necho genotypes, while the lowest was recorded in Gumero, Setit 2, Hirhir, ADI, Bounji and Aberghele. The highest mean number of seeds per capsule was recorded in Humera 1, Baha Necho, Zeri Tesfay, and Gondar 1 genotypes and the lowest was recorded in Setit 1, Setit 2 and ADI. The highest mean capsule length was observed in Zeri Tesfay while the lowest was recorded in Aberghele. The qualitative data reported that Hirhir, Setit 1 and Setit 2 were changed from completely shattering to partially shattering, Gumero and Bounji were changed from completely shattering to non-shattering, and Zeri Tesfay was changed from partially shattering to non-shattering. The 14 genotypes were clustered into four distinct groups including cluster I containing six genotypes, cluster II and III containing two genotypes each and cluster IV containing four genotypes. The mutants developed from Zeri Tesafy, ACC44 and Baha Necho genotypes are considered as potential candidate mutants for further utilization in sesame improvement.

The present study explored the effect of sodium azide (NaN3) on quantitative and qualitative leaf traits of M2 lines on 14 Ethiopian sesame genotypes collected from Humera Agricultural Research Center, Tigrai, Ethiopia. Qualitative data on leaf color, leaf hairiness, leaf arrangement, leaf shape, basal leaf profile, basal leaf margin, and leaf angle to main stem as well as quantitative data on length of basal leaf, length of top leaf, width of basal leaf, width of top leaf, length of marginal leaf, and width of marginal leaf were recorded and analyzed using analysis of variance, clustering analysis, Mahalanobis distance, and principal component analysis. Generally, treatment of seeds with NaN3 has brought many distinct and statistically significant phenotypic changes on both quantitative and qualitative leaf traits of the M2 lines. The changes in the NaN3 treated and locally adapted genotypes of Gumero and Zeri Tesfay are promising; producing the highest mean length of basal leaf (p ≤ 0.01). NaN3 treated seeds of Baha Necho, Gumero, and Hirhir developed the highest mean width of basal leaf. Locally adapted genotypes have responded positively to NaN3 treatment, generating better leaf traits as compared to the research improved ones. This study was the first of its kind in exploring the effects of NaN3 seed treatment on leaf traits of sesame genotypes. The findings of this study will, therefore, serve as a steppingstone to look into the effects of the changes in sesame yield and initiate future genetic and molecular studies on the responsive genotypes.

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.

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.