Major Sesame Research Articles

Evaluation of white seeded sesame (Sesamum indicium L.) genotypes on growth and yield performance in Menit Goldya Woreda of West Omo Zone, SWE

Sesame is the second export crop next to coffee in annual export, indicating the highest 14% of the total world export of the crop. In Africa, Sudan is the major sesame producer, followed by Nigeria, Somalia, Uganda and Ethiopia. But lack of well-adapted varieties are one of the bottleneck production problems that account for low yield and small areas cropped to the nation. Thus it is essential to evaluate such genotypes, which have high yield potential and are suitable to local environmental conditions. Therefore, field experiments were conducted at west Omo zone during 2019/20 main cropping seasons at one location of West- the Omo zone, southwest Ethiopia. The location was Menit Goldiya districts of West Omo Zone, through evaluation and selection of high-yielding sesame varieties. The study comprised of five improved and one local sesame varieties laid out in RCBD with three replications at each location. The growth and yield data were collected and analyzed by using SAS Version 9.3 statistical software. The result of the study revealed that all of the parameters considered were significantly (p < 0.01) affected by varieties on both years. Accordingly, at Menit Goldiya for, all parameters in both years and the combined analysis over the years indicated that maximum plant height, number of primary branches per plant, number of capsules per plant, thousand seed weights in grams and seed yield were observed for the Humera-1 variety. Likewise, the shortest days to flowering, early maturing, the highest length of capsule bearing zone, the maximum number of capsules per plant, the highest number of seeds per capsule and the maximum seed yield (8.13 Qu/ha) were observed for the Humera-1 variety in 2019/2020 growing seasons. Based on the mean total seed yield of locations and different yield evaluation methods, a high-yielding variety was identified. Accordingly, the Humera-1 variety performed best on both years. Therefore, this variety can play a vital role in food self-sufficiency and food security of the south-western region and it should be widely distributed to farmers of the testing locations and similar areas of the region.

Insect species dynamics and associated losses in on-farm stored sesame (Sesamum indicum L.) seeds in major sesame growing areas in Ethiopia

Insufficient storage practices and frequent infestations of insect pests pose significant obstacles to sesame production and storage, adversely affecting the quality and quantity of seeds. This forces farmers and traders to sell their crops at lower prices immediately after threshing to avoid market rejection caused by pests and mold damage during storage. The objective of this study was to investigate the insect species dynamics and the losses of on-farm-stored sesame seeds during the 2017- 2018 production year. Sesame seed samples obtained from randomly selected 431farm households in five districts were analyzed to determine the insect species present, insect density, seed weight loss, seed damage, germination percentage, and dockage using R software version 4.2.2. Biophysical parameters such as inter-granular temperature, seed moisture, and relative humidity were also recorded. Furthermore, interviews were conducted with the 431 farm households to gather information on their seed storage methods, practices for controlling insect pests, and the varieties of sesame they produce and store. The findings revealed the presence of 13 arthropod species from four orders (Coleoptera, Hemiptera, Hymenoptera, and Lepidoptera) which belongs to eight families (Tenebrionidae, Silvanidae, Bostrichidae, Curculionidae, Carabidae, Coreidae, Formicidae, and Pyralidae) in the stored sesame seeds at the study site. The most prevalent species was the flour beetle (Tribolium spp.), accounting for 44.26% of the infestation, followed by the rice moth, lesser grain borer, and rice weevil, which constituted 28.2%, 15.72%, and 4.88% of the infestation, respectively. The farmers grew and stored nine different cultivars along with one improved sesame variety called setit-1. On average, there was a 1.97% loss in seed weight, with insect pests causing damage to 8.3% of the seeds. The study districts exhibited an average of 3.79 insects per kilogram of sesame seeds, and the seeds showed a mean germination rate of 77%, which was significantly influenced by the extent of insect damage. The study underscores the significant challenges faced by sesame production and storage in Ethiopia due to inadequate storage practices and infestation by insect pests, resulting in diminished seed quality and quantity. To mitigate the losses incurred from storing sesame on farms, effective measures should be implemented, including improved storage practices and efficient pest control methods.

Soil Quality Assessment of Sesame-Growing Soils with Different Productivity in the Northern Telangana Zone, India

Present study was carried out in major sesame growing areas of Northern Telangana zone in districts namely; Nizamabad, Jagtial, Nirmal and Kamareddy. The main objective of this study is to assess the soil quality and to find out the relation between sesame yield and soil quality index. Based on the seed yield data of sesame, the above-mentioned districts were divided into high, medium and low productivity zones. 50 samples from each productivity zone with a total of 150 surface soil samples (0-15 cm were collected and analysed for various physical, physico-chemical, chemical and biological properties. Physical properties included texture, bulk density and water holding capacity. Physico-chemical properties like pH, EC and organic carbon were analysed. Chemical properties of soil namely available nitrogen, available phosphorus, available potassium, available sulphur, exchangeable bases like exchangeable calcium and magnesium, potassium and sodium, available micronutrients like iron, copper, manganese and zinc were analysed. Biological properties like urease, acid and alkaline phosphatase and labile carbon were analysed. Principal component analysis, minimum dataset was derived which contained available nitrogen, sand, pH, available phosphorus, exchangeable calcium and magnesium and urease with 70.81% variance. These are identified as the key indicators of soil quality. Mean soil quality index values were 0.669, 0.549 and 0.443 for high, medium and low sesame productivity zones respectively and is in the order of high>medium>low sesame productivity zones. Percent contribution of MDS to SQI are in the order of, available nitrogen (44.44%> pH (16.85% >exchangeable calcium (9.87%> exchangeable magnesium (8.89%> urease (7.86%> available phosphorus (7.38% > sand (4.89%. This study concluded that the SQI was more significantly positively correlated with sesame yield, which revealed that soil variables from the minimum data set had biological significance and effectively evaluated the status of the sesame growing soils of Northern Telangana Zone.

Sesamin and sesamolin potentially inhibit adipogenesis through downregulating the peroxisome proliferator-activated receptor γ protein expression and activity in 3T3-L1 cells

Sesamin and sesamolin are major sesame lignans that have demonstrated anti-inflammatory, anticancer, and neuroprotective properties and potential benefits in the liver, cardiovascular diseases, and metabolic syndrome. However, despite previous research on their antiobesity effects and underlying mechanisms, a comprehensive investigation of these aspects is still lacking. In this study, we evaluated the regulatory effects of 20 to 80 µM sesamin and sesamolin on adipogenesis in vitro using 3T3-L1 cells as a model cell line. We hypothesized that the lignans would inhibit adipogenic differentiation in 3T3-L1 cells through the regulation of peroxisome proliferator-activated receptor γ (PPARγ). Our data indicate that sesamin and sesamolin inhibited the adipogenic differentiation of 3T3-L1 cells by dose-dependently decreasing lipid accumulation and triglyceride formation. Sesamin and sesamolin reduced the mRNA and protein expression of the adipogenesis-related transcription factors, PPARγ and CCAAT/enhancer-binding protein α, leading to the dose-dependent downregulations of their downstream targets, fatty acid binding protein 4, hormone-sensitive lipase, lipoprotein lipase, and glucose transporter 4. In addition, glucose uptake was dose-dependently attenuated by sesamin and sesamolin in both differentiated 3T3-L1 cells and HepG2 cells. Interestingly, our results suggested that sesamin and sesamolin might directly bind to PPARγ to inhibit its transcriptional activity. Finally, sesamin and sesamolin decreased the phosphorylation of 3 mitogen-activated protein kinase signaling components in differentiated 3T3-L1 cells. Taken together, our findings suggest that sesamin and sesamolin may exhibit antiobesity effects by potentially downregulating PPARγ and its downstream genes through the mitogen-activated protein kinase signaling pathway, offering important insights into the molecular mechanisms underlying the potential antiobesity effects of sesamin and sesamolin.

Postharvest losses and seed storage problems in major Sesame(Sesamum indicum L.) Growing states in India

A survey was conducted on postharvest losses and seed storage problems in sesame under farmers, oil extraction mills, mandi (government-regulated grain selling and procurement market) and warehouse conditions in major sesame growing states like Gujarat, Rajasthan, Madya Pradesh, Uttar Pradesh and Tamil Nadu. It was observed a minimum of 10% to a maximum of 25% postharvest losses from harvesting to transportation of seeds to processing/ washing plant for export purposes. These losses are mainly because of shattering while harvesting, spillage during transportation, improper handling in mandi and unscientific storage methods adopted by farmers and traders.

Appraisal of the Sesame Production Opportunities and Constraints, and Farmer-Preferred Varieties and Traits, in Eastern and Southwestern Ethiopia

Sesame (Sesamum indicum L.) is an important oilseed crop with well-developed value chains. It is Ethiopia’s most valuable export commodity after coffee (Coffea arabica L.), contributing to socioeconomic development. The productivity of the crop is low and stagnant in Ethiopia and other major sesame growing regions in sub-Saharan Africa (<0.6 t/ha) due to a multitude of production constraints. The objective of this study was to document sesame production opportunities and constraints, as well as farmer- and market-preferred varieties and traits, in eastern and southwestern Ethiopia as a guide for large-scale production and breeding. A participatory rural appraisal (PRA) study was conducted in two selected sesame growing regions and four districts in Ethiopia. Data were collected from 160 and 46 sesame farmers through semistructured questionnaires and focus group discussions. Sesame is grown by all respondent farmers in the study areas for food and as a source of cash. Most respondent farmers (56%) reported cultivating sesame using seeds of unknown varieties often sourced from the informal seed sector. About 83% of the respondents reported lack of access to improved seeds as the most important production constraint, followed by low yield gains from cultivating the existing varieties (reported by 73.8% of respondents), diseases (69.4%), and low market price (68.8%). Other production constraints included insect pests (59.4%), lack of market information (55%), and high cost of seed (50%). The above constraints were attributed to the absence of a dedicated breeding programme, lack of a formal seed sector, poor extension services, and underdeveloped pre- and postharvest infrastructures. The most important market-preferred traits of sesame included true-to-type seed (reported by 36.3% of respondents), white seed colour (28.8%), and high seed oil content (23.8%). The vital farmer-preferred attributes included reasonable market price (reported by 11.3% of respondents), resistance to crop diseases (10.9%), drought tolerance (10.3%), resistance to crop insect pests (9.2%), higher seed yield (8.9%), higher thousand-seed weight (7.2%), higher oil content (6.3%), white seed colour (6.1%), early maturity (6.1%), and good oil qualities such as aroma and taste (5.7%). Therefore, there is a need for a dedicated sesame genetic improvement programme by integrating the above key production constraints and market- and farmer-preferred traits to develop and deploy new generation varieties to enhance the production, productivity, and adoption of sesame cultivars in Ethiopia.

A high yielding white seeded sesame variety:VRI 3

A high yielding white seeded sesame culture VS 07 023 was developed at Regional Research Station, Vridhachalam and released as VRI 3 during 2017. It is a cross derivative of SVPR 1 and TKG 87. The culture was evaluated for rabi and the summer seasons. The culture VS 07 023 registered overall grain yield of 995 kg/ha which is 22.74 per cent and 17.33 per cent yield increase over the check SVPR 1 (811kg/ha) and TMV (SV) 7 (848 kg/ha), respectively over 95 locations during rabi season. Similarly, the culture VS 07 023 registered remarkably a higher mean seed yield of 1055 kg/ha against the check SVPR 1 (862 kg/ha) and TMV (SV) 7 (928kg/ha). The per cent increase in the mean seed yield over the check was 22.49 (SVPR 1) and 13.77 per cent (TMV (SV) 7). The culture is moderately resistant to Macrophomina root rot disease. The culture VS 07 023 is white seeded containing 50 per cent oil content and exhibited a profuse branching suitable for rabi and the summer irrigated conditions. In view of stable performance of sesame culture VS 07 023, it was released as a new sesame variety VRI 3 during 2017 by Tamil Nadu Agricultural University, Coimbatore for cultivation in major sesame growing districts of Tamil Nadu during rabi and the summer irrigated conditions. Key wordsSesame, white seeded, new variety,VRI 3

Fatty acid composition, total phenolic contents and antioxidant activity of white and black sesame seed varieties from different localities of Ethiopia

BackgroundAuthentication of food and agricultural products is important to trace out the right product and ensure the customer’s preference and their health. Sesame (Sesamum indicum L.) is one of the most important crops used for food and medicine in Ethiopia and different varieties and cultivars are produced in different regions of the country. This study was undertaken to determine the total flavonoid content, total phenolic content, antioxidant activity, and fatty acids profile of black and white sesame seed varieties. Samples were obtained from three major sesame seed-producing districts of Ethiopia.ResultsThe total phenolic content (TPC), total flavonoid content (TFC), and the half-maximal inhibitory concentration (IC50) were ranged from 2.95 to 6.95 mgGAE/g, 2.13–4.99 mgCE/g and 8.3–16.8 AAE/g of the sample, respectively. In general, white sesame seed samples showed the highest TPC, TFC, and antioxidant activity than the black variety. Location wise, samples collected from the Metema district were found to contain a relatively higher concentration of the phytochemicals. The white seed variety was characterized by significantly higher content of oil (53.2–58.2% by mass of the sample) than the back variety (47.6–51.4%).The oil content of the seeds was found to contain nine identifiable fatty acids (FAs). The total unsaturated fatty acids constituted more than 82% of the total FAs, while the saturated FAs were lower than 18% of the total FAs. Among the unsaturated FAs, linoleic acid (C18:2, omega-6 FAs) was the dominant FA (42.5–44.3%) followed by oleic acids (37.2–38.9%). On the other hand, palmitic acids (9.35–11.2%) and stearic acid (5.78–6.52%) were the dominant FAs among the saturated FAs.ConclusionsThe studied samples had higher concentration of linoleic acid (omega-6 FA) than oleic acid, as opposed to other reported accessions of sesame seeds. Furthermore, white sesame seeds were richer in oil content than the black variety. The high concentration of unsaturated FAs, omega-6 FA, and phenolic compounds make sesame seeds nutritionally and medicinally important for the human diet. Unlike the fatty acids profiles, the level of phenolic compounds in sesame seeds was highly dependent on the geographical region and varietal type of the seeds.

Distribution of Pigeon Pea Cyst Nematode and Root-Knot Nematodes in Major Sesame Growing Areas in Myanmar

The pigeon pea cyst nematode, Heterodera cajani, is an economically important plant-parasitic nematode in sesame production. The objective of the study was to investigate distribution of H. cajani in the major sesame producing areas in Myanmar. Before cultivation, soil samples were collected in 96 local farmer’s fields: (19 fields in Magway, 20 fields in Mandalay, 14 fields in Sagaing and 43 in Nay Pyi Taw), and nematode density was quantified by real-time PCR. The cyst nematode was detected in 63.2% of the fields in Magway and the mean density was 22.6 eggs equivalent (20 g soil)−1. In Mandalay and Nay Pyi Taw, the cyst nematode was detected in 40.0% and 18.6% of the fields with the mean densities of 9.9 and 21.0 eggs equivalent (20 g soil)−1, respectively. By contrast, the cyst nematode was not detected in Sagaing fields, in which sesame is rotated with paddy rice. Infestation of root-knot nematodes (RKN, Meloidogyne spp.) was also evaluated, because sesame is generally rotated with rice and pulses, which are attacked by RKN. The results showed 25.6% infestation of RKN with a mean density of 34.3 eggs equivalent (20 g soil)−1 only in Nay Pyi Taw, while there was no infestation in Magway, Mandalay, and Sagaing. The relationships between the nematode infestation level and the cropping patterns in each sesame growing area in Myanmar were discussed.

Performance Evaluation of Sesame under Regulated Deficit Irrigation Application in the Low Land of Western Gondar, Ethiopia

Sesame (Sesamum indicum L.) is the leading oil seed crop produced in Ethiopia. It is the second most important agricultural commodity for export market in the country. It is well suited as an alternative crop production system, and it has low crop water requirement with moderate resistance to soil moisture deficit. The low land of North Western Ethiopia is the major sesame producer in the country, and the entire production is from rainfed. The rainfall distribution in North Western Ethiopia is significantly varied. This significant rainfall variability hampers the productivity of sesame. Irrigation agriculture has the potential to stabilize crop production and mitigate the negative impacts of variable rainfall. This study was proposed to identify critical growth stages during which sesame is most vulnerable to soil moisture deficit and to evaluate the crop water productivity of sesame under deficit irrigation. The performance of sesame to stage-wise and uniform deficit irrigation scheduling technique was tested at Gondar Agricultural Research Center (Metema Station), Northern Western Ethiopia. Eight treatments, four stage-wise deficit, two uniform deficit, one above optimal, and one optimal irrigation applications, were evaluated during the 2017 irrigation season. The experiment was designed as a randomized complete block design with three replications. Plant phenological variables, grain yield and crop water productivity, were used for performance evaluation. The result showed that deficit irrigation can be applied both throughout and at selected growth stages except the midseason stage. Imposing deficit during the midseason gave the lowest yield indicating the severe effect of water deficit during flowering and capsule initiation stages. When deficit irrigation is induced throughout, a 25% uniform deficit irrigation can give the highest crop water productivity with no or little yield reduction as compared with optimal irrigation. Implementing deficit irrigation scheduling technique will be beneficial for sesame production. Imposing 75% deficit at the initial, development, late season growth stages or 25% deficit irrigation throughout whole seasons will improve sesame crop water productivity.

Marketing Chain and Structure, Conduct and Performance of Sesame: The Case of Kafta Humera District, Western Zone of Tigray, Ethiopia

This study analyzed marketing chain and structure, conduct and performance of sesame in Kafta Humera district of Tigray region, Ethiopia; using primary and secondary data obtained from field survey and desk review using a semi-structured questionnaire. Multistage random sampling technique was used to draw 128 and 126 small and, large-scale sesame producers, respectively. Also, a total of 44 assemblers, 5 cooperatives, 13 exporters and one processor were interviewed. Applying the descriptive statistics method and market observation of the researcher; the major sesame market chain actors were producers, assemblers, cooperatives, exporters and processors. The concentration ratios of the first four and eight large local assemblers and exporters indicated that there was a weak oligopoly market structure. It is also found that there were entry barriers, information asymmetry and collusion in price-setting; indicating that sesame market was deviating from the norms of competitive market structure. Considering free on board of hulled sesame price; the gross marketing margins of 5%, 12% and 45% and net marketing margins of 1%, 3% and 17% obtained by assemblers, exporters and processors, respectively. But, Considering the free-on-board price of raw sesame; the gross marketing margins of 7%, 18% and about 75% and net marketing margins of 1.13%, 4.41% and 4.85% obtained by assemblers, exporters and producers, respectively. All these indicating that the sesame market was being poorly performing. Depending on the results found this study recommends, it will be better if the focus is given to value-added product export, securing competitive market through minimizing entry barriers, strengthening timely updated market information and formal credit access, hiring marketing experts at market centres to control collusion of traders in price setting.

Variability of Macrophomina phaseolina (Tassi.) Goid. the causal organism of root rot of sesame and its management

Ten isolates of Macrophomina phaseolina (Tassi) Goid. (sclerotial stage: Rhizoctonia bataticola (Taub) Butler) collected from different major sesame growing areas of Telangana, Karnataka and Andhra Pradesh were studied for their variability on morphological, cultural and pathogenic characteristics. The hyphal cell size varied from 13.75 x 3.75 μm (Mp 9) to 31.39 x 4.5 μm (Mp 5), size of sclerotia varied from 82.41 x 58.90 μm (Mp 6) to 135.18 x 101.88 μm (Mp 8). Based on shape of sclerotia the isolates were classified in to three groups. irregular, round and ovoid groups. The number of sclerotia per microscopic field at 10x varied from 14 (Mp 2) to 42 (Mp 7). There was no significant difference in the colony growth rate recorded among the isolates of M. phaseolina which varied from 7.66 to 8.65 mm, Isolates categorized into three groups viz., partially submerged, submerged, fluffy on the basis of colony texture and colony colour varied from black, grey and light grey colour. Based on the disease incidence isolates were categorized into two categories viz., virulent (2 isolates) and highly virulent (8 isolates).

Trends in extreme temperature and rainfall indices in the semi-arid areas of Western Tigray, Ethiopia

BackgroundAfrica is the most vulnerable continent in the world; which recurrent droughts, extreme temperature and rainfall affects agriculture and food security. The aim of this study was to analyze the trends in extreme temperature and rainfall in major sesame producing areas in western Tigray using RClimDex software. We selected eight temperature and nine rainfall indices from 27 extreme temperature and rainfall indices, which are recommended by joint CCL/CLIVAR/JCOMM Expert Team on Climate Change Detection and Indices (ETCCDI). A non-parametric Mann–Kendall test and Sen’s slope estimates were used to test the statistical significance and trend of each of the extreme temperature and rainfall indices, respectively.ResultsNumber of heavy rainy days, number of very heavy rainy days, very wet days, extremely wet days, and maximum 5 days precipitation showed a negative trend, with significant (p < 0.05) decrease throughout the study area. Monthly maximum value of maximum and minimum value of maximum temperature, monthly maximum and minimum value of minimum temperature, hot days and hot nights revealed positive trend throughout the study areas. Total rainfall was decreasing significantly (p < 0.05) by 13.34 mm, 13.8 mm, 14.65 mm, 10.9 mm and 8.4 mm/year at Humera and Dansha, Adiremets, Maygaba, Maytsebri and Sheraro, and Adigoshu, respectively. Spatial analysis on extreme temperature also indicated there was relatively lower variability on minimum temperature in Humera, Dansha, Adiremets, and Adigoshu. On average, the western part of Tigray experienced a reduction in total rainfall ranging 8.45 to 14.7 mm/year; and increase in average maximum temperature of 0.04 to 0.051 °C/year since 1983 to 2016. The results also revealed an increase in warm nights and warm days ranging from 0.31 to 0.62 days, and 0.38 to 0.71 days/year, respectively.ConclusionsIncrease in temperature and decrease in amount of rainfall may have a negative impact on crop transpiration, photosynthetic rate and soil water balance; exacerbating distribution and infestation of malaria and leishmaniasis. The results in this study could have an important role in identifying possible present and future production strategies on sesame, cotton, and sorghum crops, which are essential cash crops produced by farmers and investors.

Occurrence of Different Kinds of Diseases in Sesame Cultivation in Myanmar and Their Impact to Sesame Yield

We surveyed diseases of sesame in 10 farmers’ fields at Nay Pyi Taw, Myanmar and did interviews 25 farmers for the occurrence of diseases and its impact on yield in Magway, the major sesame growing area in Myanmar. We found phyllody, charcoal rot (root and stem rot), Alternaria leaf blight, powdery mildew, and leaf curl, based on on-site symptoms and their microscopic observation in Nay Pyi Taw. The disease incidence ranged from 5% to 30% in phyllody, from 10% to 30% in charcoal rot (root and stem rot) and 10% to 40% in Alternaria blight, while leaf curl and powdery mildew were not observed abundantly. According to interviews conducted in Magway, 60% of the farmers suffered from phyllody disease symptoms, 80% from charcoal rot, 48% from Cercospora, 28% bacterial leaf spot and 24% diseases with the symptoms of leaf roll. Most farmers (84%) noticed combinations of diseases symptoms either phyllody or charcoal rot/black and stem rot or Cercospora leaf spot and/or bacterial leaf spot. Yield losses ranged from 5 to 50% by phyllody, from 10 to 75% by charcoal rot (root and stem rot), from 5 to 50% by Cercospora leaf spot, and 5% by bacterial leaf spot. Other abnormal symptoms such as discoloring of root, seedling death and leaf yellowing were also observed and the yield losses ranged from 5 to 50%.There were no significance relations between the actual yield and yield losses estimated by each disease. A half of farmers (54%) burnt the crop residues after harvest, while 45% directly buried them in their fields including plant parts infected with diseases. Although there was no difference in sesame yield between these two practices, the average yield was higher by 15% in farmers with the burnt practice. Only a few farmers applied fungicides. Potential constraints to cause yield reduction and necessary actions to increase sesame yield are discussed.

Evaluation of sesame (Sesamum indicum L.) Varieties for Seed Yield and Yield Components under Bacterial Blight (Xanthomonas campestris pv. sesami) Disease Pressure in Western Tigray, Northern Ethiopia

Yield reduction in sesame production in Ethiopia has been attributed to many biotic and abiotic factors. From among the biotic factors, bacterial blight (Xanthomonas campestris pv. sesami) disease is a major constraint across the major sesame growing areas. A study was conducted on farmers’ field at Dansha (northern Ethiopia), “hot spot area” for bacterial blight disease, to identify the level of resistance to bacterial blight disease in some sesame varieties and assess the corresponding productivity of the varieties under natural disease pressure. The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. Highly significant differences (p<0.01) were observed in days to 50% flowering and maturity, number of branches and capsules per plant, plant height, seeds per capsule, 1000-seed weight, yield (kg/ha), oil content (%) percentage severity index (%) and AUDPC values. The mean maximum yield (651.7 kg/ha) was obtained from variety Gida-Ayana whereas, the lowest mean grain yield (428.3 kg/ha) was obtained from variety Hirhr. Variety Gida-Ayana had the lowest disease development and had the highest seed yield and percent oil content than the rest of the varieties tested. Thus, variety Gida-Ayana is identified as the most promising variety to be produced in the bacterial blight problem areas of northern Ethiopia.

Characterization of Structural Variability of the Allergenic 2S Albumin Ses i 1 Using Combinatorial Proteomics

Allergy to sesame seeds is a food allergy of high relevance due to its high abundance and the potential to elicit allergenic reactions, possibly resulting in anaphylaxis. The major sesame allergen Ses i 1 is a 2S albumin belonging to the family of seed storage proteins and despite its high allergenicity, comprehensive knowledge about Ses i 1 variants is still lacking. We, therefore, performed a detailed sequence analysis and characterized the C- and N-terminal ragged clipping of the small and large subunit of Ses i 1 using high-resolution mass spectrometry and the combination of bottom–up, middle–down, and top–down proteomic approaches. We detected extensive clipping at the C-terminus of the large (3–9 aa) and the small subunit (0–7 aa). In addition, the N-terminal conversion from glutamine to pyroglutamate and limited N-terminal clipping was confirmed for both subunits. Furthermore, we observed a sequence conflict at position 147 of Ses i 1 as well as a sequence shift of the large subunit compared to the reference sequence of the precursor.

Genetic diversity and vector transmission of phytoplasmas associated with sesame phyllody in Iran.

During 2010-14 surveys in the major sesame growing areas of Fars, Yazd and Isfahan provinces (Iran), genetic diversity and vector transmission of phytoplasmas associated with sesame phyllody were studied. Virtual RFLP, phylogenetic, and DNA homology analyses of partial 16S ribosomal sequences of phytoplasma strains associated with symptomatic plants revealed the presence of phytoplasmas referable to three ribosomal subgroups, 16SrII-D, 16SrVI-A, and 16SrIX-C. The same analyses using 16S rDNA sequences from sesame phyllody-associated phytoplasmas retrieved from GenBank database showed the presence of phytoplasmas clustering with strains in the same subgroups in other Iranian provinces including Bushehr and Khorasan Razavi. Circulifer haematoceps and Orosius albicinctus, known vectors of the disease in Iran, were tested for transmission of the strains identified in this study. C. haematoceps transmitted 16SrII-D, 16SrVI-A, and 16SrIX-C phytoplasmas, while O. albicinctus only transmitted 16SrII-D strains. Based on the results of the present study and considering the reported presence of phytoplasmas belonging to the same ribosomal subgroups in other crops, sesame fields probably play an important role in the epidemiology of other diseases associated with these phytoplasmas in Iran.

Immunological Characterization of Dutch Sesame Seed-Allergic Patients

Background: Sesame seed is an allergen of growing importance worldwide. However, knowledge of the clinically relevant sesame allergen and its cross-reactivity with homologous allergens is limited. The aim of this study was the immunological characterization of Dutch sesame seed-allergic patients and evaluation of cross-reactivity between sesame seed, tree nut and pollen allergens using different sources of allergen extracts. Methods: Six patients with a medical history of sesame seed allergy were included, i.e. 5 with an anaphylactic reaction and 1 with an oral allergy syndrome (OAS). The immunological background of the sesame seed and tree nut IgE sensitization was characterized with Western blotting and a basophil activation test (BAT). The major sesame allergen was identified by nanoLC-MS/MS. Cross-reactivity was measured using an immuno-inhibition assay with the Phadia ImmunoCAP system. Results: Oleosin was identified as the major allergen for the 5 patients with an anaphylactic reaction to sesame seed, but no cross-reactivity between sesame and tree nut proteins was observed. For the patient with OAS, IgE specific to oleosin was not detected but cross-reactivity between sesame seed and tree nut proteins was observed. The BAT and ImmunoCAP inhibition test added value to the clinical and immunological characterization of sesame seed-sensitized patients, distinguishing relevant and non-relevant sensitizations. Conclusions: Our immunological approach enabled us to fully characterize the sensitization pattern of 6 sesame seed-allergic patients. The different protein composition of commercially available allergen extracts influences the outcomes of the immunological assays and thus also the diagnosis to a large extent.

DFT study of radical scavenging activity of sesame oil lignans and selected in vivo metabolites of sesamin

DFT calculation of various molecular descriptors was carried out in order to examine the radical scavenging properties of sesame oil lignans and some selected metabolites of sesamin formed in vivo. The major sesame oil lignans, namely sesamin and sesamolin may present antioxidant activity through hydrogen atom transfer, though lacking a phenolic group. This can be achieved via the contribution of allylic hydrogen atoms according to C–H bond dissociation enthalpy (BDE) values. Even so, the predicted activity is not higher than that of some phenolic derivatives (e.g. pinoresinol) or metabolites bearing catechol moieties. The contribution of non-phenolic hydrogen atoms may result in the formation of planar or semi-planar conjugated compounds. Some of the tested lignans (e.g. sesaminol, sesamolinol) may be efficient electron donors comparable to active flavonoids according to ionization potential (IP) values. Neutral sesamol can be an efficient electron donor rather than hydrogen atom donor according to IP and net electrophilicity values. Only computation in water could partially justify literature experimental findings on the higher reactivity of sesamol over that of sesamin. The metabolites of sesamin, bearing one or two catechol groups were found as the most efficient hydrogen atom donors and most prone to ionization. Therefore, they could be capable to act efficiently via hydrogen atom transfer (HAT) or sequential proton loss electron transfer (SPLET) in real systems as shown by gas-phase and calculations in solvents (benzene, water). Thus, these metabolites may account for the high in vivo antioxidant activity of sesamin. Examination of the succeeding products of metabolism indicated the progressive loss of radical scavenging efficiency which was predicted to be negligible in the compounds excreted from the body of mammals.

Development of simple sequence repeat (SSR) markers of sesame (Sesamum indicum) from a genome survey.

Sesame (Sesamum indicum), an important oil crop, is widely grown in tropical and subtropical regions. It provides part of the daily edible oil allowance for almost half of the world’s population. A limited number of co-dominant markers has been developed and applied in sesame genetic diversity and germplasm identity studies. Here we report for the first time a whole genome survey used to develop simple sequence repeat (SSR) markers and to detect the genetic diversity of sesame germplasm. From the initial assembled sesame genome, 23,438 SSRs (≥5 repeats) were identified. The most common repeat motif was dinucleotide with a frequency of 84.24%, followed by 13.53% trinucleotide, 1.65% tetranucleotide, 0.3% pentanucleotide and 0.28% hexanucleotide motifs. From 1500 designed and synthesised primer pairs, 218 polymorphic SSRs were developed and used to screen 31 sesame accessions that from 12 countries. STRUCTURE and phylogenetic analyses indicated that all sesame accessions could be divided into two groups: one mainly from China and another from other countries. Cluster analysis classified Chinese major sesame varieties into three groups. These novel SSR markers are a useful tool for genetic linkage map construction, genetic diversity detection, and marker-assisted selective sesame breeding.