https://orcid.org/0000-0002-2515-7050
Figures
Abstract
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.
Citation: Weldemichael MY, Bitima TD, Abrha GT, Tesfu K, Gebremedhn HM, Kassa AB, et al. (2023) Improving desirable agronomic traits of M2 lines on fourteen Ethiopian Sesame (Sesamum indicum L.) genotypes using Ethyl Methane Sulphonate (EMS). PLoS ONE 18(9): e0287246. https://doi.org/10.1371/journal.pone.0287246
Editor: Alia Ahmed, University of Balochistan, PAKISTAN
Received: November 11, 2022; Accepted: June 2, 2023; Published: September 26, 2023
Copyright: © 2023 Weldemichael et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the paper.
Funding: This research was supported by the Ethiopian Institute of Agricultural Research (grant number EIAR/025/2019). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
Introduction
Sesame (Sesamum indicum L., 2n = 26) is one of the ancient oilseed crops widely cultivated, mainly in the arid and semi-arid regions of Africa, Asia and South America, as a source of high-quality oil and edible seeds [1, 2]. Sesame seed has a high oil quality and quantity, nutrition, cosmetic and pharmaceutical uses [3]. Sesame seeds are known to be rich in carbohydrate, protein, oil, and dietary fiber [4]. Besides, sesame seed has abundant applications for nutritional, industrial and pharmaceutical uses due to its high oil quality, high oil content, and strong resistance to oxidation, and hence is referred as the ‘queen of oilseeds’ [1, 5]. Compared to the seeds of other main oil crops, such as peanut (Arachis hypogea), rapeseed (Brassica napus), soybean (Glycine max), and olive (Olea europaea), sesame seeds not only have the highest oil content, but also are rich in vitamins and minerals [6]. Moreover, sesame seed is an excellent source of vegetable oil which is rich in polyunsaturated fatty acids, phytosterols, tocopherols, and unique classes of lignans such as sesamolin and sesamin, all of which are known as important compounds for human health [1, 7]. Sesamin is endowed with anti-cancer property [8, 9], whereas sesamol has a powerful functional ingredient for treating cardiovascular diseases [10]. In addition, sesame seed serves as a major component in the production of cosmetics, soaps, perfumes, pharmaceutical products, and insecticides [11]. As a result of such wider economical, industrial, nutritional and medicinal significances, the demand for sesame oil consumption is forecasted to reach about 220.46 million tons by 2030 [12]. Improving the production and productivity of this oilseed crop, Sesamum indicum L., is hence prominent to alleviate the alarmingly growing demands of oil. However, the production and productivity of sesame are challenged by numerous factors including early flowering, shattering, indeterminate growth habit, and branching as well as diseases and insect-pests such as bacterial blight, Cercospora leaf spot, Fusarium wilt, phyllody, webworm and aphids as major ones, which are causing significant yield losses every year.
Sesame yield is highly affected by numerous factors including plant height, growth habit, branching habit, internode length, and flowers per leaf axial [13–17]. The low yield potential of sesame, as compared to other oilseed crops, is mainly due to its indeterminate growth habit, which is characterized by continuous flowering and non-uniform ripening of capsules [14]. In addition, plant height and internode length are among the most important agronomic traits for sesame production [18], which lead to low yielding capacity, low harvest index, lodging, and susceptibility to various biotic and abiotic stresses [19]. Hence, enhancing sesame production and productivity through the improvement of these traits is among the significant aims of sesame breeding programs [20, 21]. As a result, various chemical mutagens such as EMS, diethyl sulfate, colchicine, sodium azide, and hydrazine hydrate have been used in different crops [22, 23].
Chemical mutagens, chemical agents that permanently change genetic material, are vital to significantly reduce plant height and enhance lodging resistance so as to increase sesame production [22]. Induced mutation using EMS is an easy and inexpensive alternative for breeding of crops to improve yield, early maturity, quality traits, as well as to confer resistance against biotic and abiotic stresses [23]. Seeds treated with EMS enhanced sesame yield through the growth of cultivars with determinate growth habit, synchronous maturity and earliness, improved pod shattering resistance, resistance to diseases, larger seed size, male sterility, higher oil content and modified fatty acid composition [24]. Furthermore, a gene SiDt was detected as a target gene for conferring the determinate trait in sesame cultivar using genetic mapping and genomic association studies [13]. Similarly, Sidwf1 was reported as a gene controlling short internode length and dwarfing trait in dw607 mutant sesame [16]. Another candidate gene (SiBH) for branching habit, an important trait in sesame affecting cultivation practice and mechanical harvesting, was reported to facilitate mechanical harvesting without compromising seed yield [17]. More recently, the work of Weldemichael et al. [25] revealed the effects of sodium azide on various quantitative and qualitative stem traits of M2 lines on fourteen Ethiopian sesame genotypes. However, an intensive mutation breeding using EMS targeting key functional agronomic traits for the Ethiopian sesame genotypes is still demanding. Therefore, it is vital to develop new mutants using EMS, which can accelerate the breeding program and improve sesame genotypes. The main objective of this study was to use EMS to induce desirable agronomic traits in 14 Ethiopian sesame genotypes, with the aim of accelerating breeding programs and improving the crop’s productivity.
Materials and methods
Experimental site
In this study, both laboratory and field experiments have been conducted. The laboratory experiment was carried out at Tigrai Biotechnology Center, Pvt. Ltd. Co. in Mekelle city, Tigrai region, northern Ethiopia (Lat.: 13° 30′ 0″ N; Long.: 39° 28′ 11″ E; Alt. 2,080 masl). In addition, the field evaluation of the fourteen sesame genotypes was undertaken in three environments, namely Humera (14°15′ N, 36°37′ E), Kebabo (13°36′ N, 36°41′ E), and Sheraro (14°24’ N, 37°45’ E) for two rainy seasons, 2019 and 2020 (Fig 1). The three sites have similar climatic conditions and represent the major sesame production areas in Ethiopia [26].
The image was taken from fourteen sesame genotypes planted in three locations. A. Humera, B. Kebabo, C. Sheraro.
Collection of seeds and sterilization
Sesame seeds of fourteen genotypes comprising four landraces, an introduced variety from Israel and nine varieties released from different research centers in Ethiopia, which were acquired from Humera Agricultural research center (HuARC), Tigrai, Ethiopia, were used in this study (Table 1). Disease-free, dry and normal shaped seeds were used for the experiment. The seeds were soaked in 3% teepol detergent solution for 5 min after being washed with running tap water for 20 min and rinsed with distilled water. 70% ethanol was used to disinfect the seeds for 45 sec at room temperature and rinsed with sterile distilled water three times. Sulfuric acid and glacial acetic acid were used to treat the seeds and soaked in sterile distilled water for 16 hrs [25, 27].
Treatment with EMS
Different concentrations of EMS, i.e. 0.0, 0.25%, 0.5%, 0.75%, and 1% were studied to find the optimum concentration [29, 30]. Seeds of 14 sesame genotypes were pre-soaked in cold tap water at 4°C for 24 hrs and then soaked in 0.5% EMS solution (HiMedia Laboratories, Pvt. Ltd., Mumbai-400086, India) with Sörenson phosphate (Sigma-aldrich, Munich, Germany) as a buffer adjusted to pH = 3 with H3PO4 (Sigma-aldrich, Munich, Germany) for 4 hrs with constant shaking at 20 rpm at 18–24°C. EMS is a mutagenic chemical, and it is important to reduce the harmful effects of EMS on the environment and human health, provided it is properly stored, used, disposed of, and transported. The procedures developed in the work of Weldemichael et al. [25] were used in this study. After washing, both the treated and control seeds were planted in well prepared beds in Kebabo, Humera and Sheraro to get M1 lines. Untreated seeds of all genotypes have been used as control for comparison throughout the experiment. Besides, no data were taken from M1, which was rather advanced into M2 (second generation mutant) lines from which all the quantitative and qualitative data were used for analyses in this study. Finally, the M2 plants derived from the M1 seeds were being considered as mutants.
Field evaluation and recorded data of M2 lines
The experiment was laid down in a randomized complete block design (RCBD) having three replications. Each genotype of the M2 lines was randomly assigned and sown in rows, in a plot area of 2.8m by 5m with 1m between plots and 1.5m between blocks keeping inter- and intra-row spacing of 0.4m and 0.1 m, respectively. Each experimental plot was treated equally as per the agronomic recommendations for the crop in the growing area. During the growth period, all required production practices like weed management and fertilization were carried out as recommended. Data were collected from fifteen plants of each M2 sesame lines at 75% maturity. Both quantitative and qualitative data (all in cm) were recorded properly from all the treated and control genotypes. Recorded quantitative data include: ground distance to first branch (GDFB), internode length (IL), plant height (PH), length of basal leaf (LBL), length of top leaf (LTL), width of basal leaf (WBL), width of top leaf (WTL), length of marginal leaf (LML), width of marginal leaf (WML), petiole length of basal leaf (PLBL), petiole length at middle (mid-level/mid-height) leaf (PLML), petiole length of top leaf (PLTL). Likewise, recorded qualitative data were: main stem color (MSC), stem hairiness (SH), stem branch (SB), plant growth type (PGT), branching pattern (BP), stem shape in cross section (SSCS), leaf color (LC), leaf hairiness (LH), leaf arrangement (LA), leaf shape (LS), basal leaf profile (BLP), basal leaf margin (BLM), lobe incision of basal leaf, and leaf angle to main stem (LAMS) (Table 2).
Data analyses
The collected data for the different quantitative and qualitative traits were measured and subjected to analysis of variance (ANOVA) using GenStat 16 Software [32]. Post-ANOVA mean comparisons were carried out using Duncan’s Multiple Range Test at a significance level of p ≤ 0.01 [33].
Results
Effects of EMS on quantitative agronomic traits of M2 lines
Results of ANOVA clearly indicated highly significant effects among the genotypes, concentrations of EMS and their interaction effect on the quantitative data including GDFB, IL, LTL, WBL, WTL, LML, WML, and PLTL (p ≤ 0.01; Table 3). On the other hand, the remaining quantitative leaf traits including LBL, PH, PLBL, and PLML showed non-significant interaction effect among the genotypes and concentrations of EMS (Table 3).
The interaction effects of EMS treatment on the different quantitative traits including PH, GDFB, IL, LBL, WBL, LML, WML, LTL, WTL, PLBL, PLML, and PLTL were analyzed in this study (Table 4). Accordingly, the highest plant height was observed in the control genotypes Humera 1 (116.7 cm) and Zeri Tesfay (106.7 cm), whereas the lowest was recorded in Setit 1 (56.0 cm) and Setit 2 (52.0 cm) genotypes treated with EMS. The best ground distance to first branch was recorded in the control genotypes including Borkena (25.67 cm), Gumero (24.00 cm), Baha Necho (23.33 cm), ACC44 (22.67 cm) and Zeri Tesfay (22.67 cm). On the other hand, the treated genotypes with the least ground distance to first branch were Setit 1 (7.67 cm) and Setit 3 (8.00 cm). The highest internode length was recorded in the control genotype Setit 3 (15.33 cm) while the lowest was observed in ADI (3.00 cm), Hirhir (3.00 cm) and ACC44 (3.67 cm) genotypes treated with EMS.
The best mean LBL values were recorded in the treated genotypes of Burkena (21 cm), Bounji (16 cm), Gumero (16 cm), Humera 1 (15 cm), and Zeri Tesfay (15 cm). On the other hand, the lowest mean LBL values were observed in both the control and treated genotypes of Setit 1, Setit 2, and Setit 3 (7–10 cm). The highest mean WBL value was observed in treated genotype of Gumero (13.83 cm), while the lowest mean WBL value was recorded in the control genotype of Setit 2 (5.00 cm). The highest mean LML values were observed in the treated genotypes of Zeri Tesfay (23.00 cm), Gumero (22.67 cm), and ACC44 (21.67 cm). On the other hand, the shortest mean LML values were recorded in the control genotypes of Setit 2 (10.00 cm), Setit 1 (11.00 cm), ACC44 (11.17 cm), Borkena (11.33 cm) and Setit 3 (11.33 cm). With regard to WML, the longest mean values were recorded in the treated genotypes of Baha Necho (12.33cm) and Baha Zeyit (11.33cm), while the shortest mean values were recorded in the treated genotype Setit-2 (4.33 cm) and the control genotype Setit-1 (4.67 cm). The highest mean LTL values were observed in the treated genotype Setit 3 (8.67 cm) and control genotype Zeri Tesfay (8.00 cm). On the other hand, the lowest mean LTL was observed in the EMS treated genotypes Setit 1 (4.00 cm) and Zeri Tesfay (4.33 cm) as well as in the control genotypes Setit 1 and Setit 2 (4.40 cm and 4.33 cm, respectively). The longest mean WTL values were observed in the control Hirhir (6.33 cm), Humera 1 (5.67 cm) and Baha Zeyit (5.67 cm) as well as the EMS treated Setit 3 (6.33 cm) genotypes. On the other hand, the lowest mean WTL values were observed in the treated genotypes of Baha Zeyit, Setit 1, ADI, and Zeri Tesfay (2.07, 2.17, 2.33, 2.50 cm, respectively). The longest mean PLBL values were observed in control of Zeri Tesfay (13.33 cm), Seti 2, Hirhir, Bounji, Borkena, and ACC44 (13.00 cm). On the other hand, the lowest mean PLBL values were recorded in all of the treated genotypes except Hirhir and Setit 2. The longest mean PLML values were recorded in the control genotypes of Hirhir and Zeri Tesfay (16.33 cm) followed by ADI, Borkena, and Humara 1 (16.00 cm), while the lowest mean PLML value was recorded in the treated genotype Setti 3 (9.33cm). Similarly, the control genotypes showed higher PLTL values as compared to the treated ones, the highest mean PLTL values being recorded from the control genotypes Setit 1, Hirhir, and Humera 1 (14.67, 14.33 and 14.00 cm, respectively) while the lowest being recorded from the treated Humera 1 (3.67 cm) genotype.
Effects of EMS on qualitative agronomic traits of M2 lines
In this study, the treatment of seeds with EMS was found to be instrumental to bring major changes in multiple agronomic traits of the M2 lines of the tested Ethiopian sesame genotypes. The genotypes, EMS concentrations, and their interaction effects showed significant changes on the fourteen qualitative agronomic traits, namely main stem color, stem hairiness, stem branch, leaf shape, basal leaf profile, basal leaf margin, lobe incision of basal leaf, and leaf angle to main stem. However, the application of EMS did not result in any significant changes in plant growth type, branching pattern, stem shape in cross section, leaf color, leaf hairiness, or leaf arrangement in any of the genotypes tested (Table 5).
- Main stem color. Qualitative analysis for main stem color indicated a purplish green for 100% of the treated genotypes ACC44, ADI, Gondar 1, Setit 1, Setit 2, and Setit 3. On the other hand, genotypes such as Baha Necho, Baha Zeyit, Borkena, Gumero, Hirhir, Humera 1, and Zeri Tesfay remained green whether treated with EMS or not.
- Stem hairiness. The treatment of seeds with EMS caused changes in the stem hairiness from weak or sparse to medium in the genotypes ADI, Baha Necho, Baha Zeyit, and Borkena. In addition, significant change was observed in stem hairiness of Bounji, Hirhir, Humera 1, Gondar 1, Setit 1 and Zeri Tesfay genotypes from glabrous to weak/sparce. On the other hand, the application of EMS did not change the steam hairiness of the genotypes ACC44, Setit 2, and Setit 3.
- Stem branch. The treatment of seeds with EMS significantly changed the stem branch in ADI, Baha Necho, Bounji, Gumero, Hirhir and Setit genotypes from opposite to mixed. On the other hand, no change was observed in the genotypes ACC44, Baha Zeyit, Borkena, Gondar 1 and Humera 1 genotypes when treated with EMS.
- Leaf shape. The treatment of seeds with EMS brought changes in the shapes of the leaves in two genotypes, namely Hirhir and Setit 1, from lanceolate to ovate. On the other hand, all the other genotypes showed no change when treated with EMS.
- Lobe incision of basal leaf. EMS treatment of the seeds caused changes in basal leaf profile in ADI, ACC44, Setit 1, Setit 3, and Gondar 1 genotypes from absent to weak. In addition, genotypes like Baha Necho, Baha Zeyit, Borkena, Bounji, Gumero, Hirhir, Humera 1, Setit 2 and Zeri Tesfay showed a significant change in basal leaf profile from absent to medium.
- Basal leaf profile. EMS treatment brought about significant changes in basal leaf profile in ACC44, ADI, Bounji, Hirhir, Setit 1, Setit 2, and Setit 3 genotypes from flat to reverse cup shaped. The remaining genotypes showed no change when treated with the chemical mutagen.
- Basal leaf margin. The treatment of EMS caused changes in basal leaf margin in ACC44, Baha Necho, Baha Zeyit and Bounji genotypes from entire to serate. The remaining genotypes, however, did not show any change when treated with the chemical.
- Leaf angle to main stem. Treatment of EMS brought significant changes in the leaf angle to main stem in five genotypes. Changes from dropping to acute were observed in ACC44, Setit 2 and Setit 3; from dropping to horizontal in Borkena; and from horizontal to acute in Humera 1 genotypes.
Discussion
Sesame (Sesamum indicum L.) is an important oilseed crop used for food, feed, medicinal and industrial applications. Inherently, low genetic yield potential and susceptibility to biotic and abiotic stresses contribute to low productivity in sesame. Mutation breeding has been one of the breeding strategies used to minimize yield reducing factors in sesame [34]. As a result, more than 147 sesame mutants associated with various agronomic traits, such as leaf, capsule, male sterility, flower, disease resistance, and maturity, have been reported globally [35–37]. For example, in Egypt, Cairo white 8 and Senai white 48 mutants were developed using induced mutations and released for their nonbranching habits and white seed coat color [35]. In addition, various mutant sesame varieties with increased yield, high oil content and resistance to diseases such as phytophthora blight were developed and released in India, South Korea, and Sri Lanka [34, 38, 39]. In Ethiopia, however, yield remained very low due to a diverse set of factors, including shattering capsules, determinate growth habit, branching, reduced plant height, diseases, insect pests, drought, waterlogging, salinity, and lodging. So far, no study has been conducted to improve the aforementioned desirable agronomic traits of Ethiopian sesame genotypes through mutation breeding. Therefore, improvement of sesame using mutation breeding would play a vital role to identify superior genotypes with desirable oil and yield, shattering resistance capsules, improved branching habit, determinate growth, and better number of capsules per plant. On the other hand, limitations and drawbacks of mutation breeding as a means of genetic improvement in sesame plants including low frequency, pleiotropic effects, undesirable side effects, lethal mutations, and difficult selection process would be taken in to considerations.
In this study, desirable qualitative and quantitative plant height related traits were investigated in 14 sesame genotypes using induced mutation with EMS. As a result, the lowest plant height was recorded from Setit 1 (56.0 cm) and Setit 2 (52.0) treated with EMS. These results were in line to those of Zhang et al. [11] where plant height of mutant genotypes was reduced from 170 to 110 cm. Moreover, the results of this study were consistent with previous studies that have shown a significant reduction in plant height of mutated dw607 (dwf1) using EMS mutagenesis [16, 38]. According to their findings, the plant height was reduced by more than 40% (from 176.00 to 118.25 cm) as compared to the wild type, Yuzhi 11. This finding demonstrated that yield of dwarf varieties derived from dw607 significantly increased under suitable management conditions. These findings suggest that mutation breeding is crucial for producing sesame genotypes with desirable traits, such as determinate growth habit, shattering resistant capsules, synchronous flowering, and homogeneous maturity in a short time. To the best of our knowledge, all the sesame genotypes used in this study had indeterminate growth habits, thus causing non-uniform ripening of capsules that make mechanical harvesting difficult and result in seed loss at harvest. These results agree with the findings of other studies, in which induced mutation improved desirable agronomic traits such as determinate growth in sesame [40]. According to these data, the maximum plant height acceptable for all harvest was 150 cm and lower plants were more preferable [20]. This finding has important implications for developing sesame genotypes having lower plant height. Besides, these findings suggested that higher plant height usually shows less fruiting density, is associated with shy branching, sensitive to lodging, undesirable for high yield and unsuitable for mechanical harvesting, urging more investigation for the development of dwarf sesame genotypes. As a result, reduction of plant height after seed treatment with sodium azide at low pH value has been reported [41–43]. The combination of these findings hence supports the conceptual premise that plant height decides the plant architecture and contributes a significant role in the yield of sesame [44]. In addition, dropping plant height as a means of enlightening lodging resistance is very significant for sesame breeders. Thus, early flowering, increased yield, and reduced plant height are imperative targets for the genetic improvement of sesame.
With regard to internode length, several gammas irradiated mutant lines have been described in St. Augustine grass and in bermudagrass [45–47]. The dwarfing trait and short internode length have also been reported in the mutant dw607 [16]. In the present study, short internode length was observed on ACC44, ADI and Hirhir genotypes treated with EMS. The findings of this study validate the findings of the previous works in identifying the role of chemical mutagens to improve genetic diversity in higher plants [48, 49]. Besides, the results of this study agree with the previous studies, which have been developed to facilitate the identification, isolation and cloning of genes used in designing crops with improved quality and yield traits in many crops such as barley, cotton, rice, peanuts, wheat, and beans [50]. These findings suggest that the observed variations in sesame genotypes are due to the induced mutations.
Conclusion
The study analyzed the effect of EMS on improving desirable agronomic traits in M2 lines of fourteen Ethiopian sesame (Sesamum indicum L.) genotypes. This study showed significant changes in the majority of the qualitative and quantitative agronomic traits for the first time in Ethiopian sesame genotypes using EMS. EMS is a powerful chemical mutagen that can potentially produce desirable agronomic traits. Improving the determinate growth habit of sesame, reducing the plant height and inter node length would lead to synchronous maturity and facilitate mechanical harvesting, reducing yield losses at harvest. Further investigations to develop mutant sesame genotypes with other desirable traits such as larger seed size, improved pod shattering resistance, determinate growth habit, more uniform and shorter maturation period, modified plant architecture and size, earliness, resistance to diseases as well as higher oil content and modified fatty acid composition are strongly recommended. Moreover, the genetic variability induced in sesame plants after mutagenesis should be determined by marker assisted selection.
Acknowledgments
The authors are highly grateful to the Tigrai Biotechnology Center Pvt. Ltd. Co. for providing laboratory facilities, Humera Agricultural Research Center for provision of seeds and field evaluation sites, and the Shire-Maytsebri Agricultural Research Center for providing filed evaluation sites. We also extend our sincere appreciation to all colleagues who contributed during the research period.
References
- 1. Anilakumar KR, Pal A, Khanum F, Bawa AS. Nutritional, medicinal and industrial uses of sesame (Sesamum indicum L.) seeds-an overview. Agriculturae Conspectus Scientificus. 2010;75(4):159–68.
- 2. Zhou R, Liu P, Li D, Zhang X, Wei X. Photoperiod response-related gene SiCOL1 contributes to flowering in sesame. BMC plant biology. 2018;18(1):1–16.
- 3. Ashri A. Sesame breeding. Plant breeding reviews. 1998;16:179–228.
- 4. Makinde F, Akinoso R. Nutrient composition and effect of processing treatments on anti nutritional factors of Nigerian sesame (Sesamum indicum Linn) cultivars. International Food Research Journal. 2013;20(5):2293.
- 5. Wu M-S, Aquino LBB, Barbaza MYU, Hsieh C-L, De Castro-Cruz KA, Yang L-L, et al. Anti-inflammatory and anticancer properties of bioactive compounds from Sesamum indicum L.—A review. Molecules. 2019;24(24):4426. pmid:31817084
- 6. Yuan Q, Zhang H, Miao H, Duan Y, Wei Q, Wang X. Effects of water logging stress on the quality of sesame seed and oil product. Acta Agri Bor-Sin. 2018;33(2):202–8.
- 7. Pathak N, Rai A, Kumari R, Bhat K. Value addition in sesame: A perspective on bioactive components for enhancing utility and profitability. Pharmacognosy reviews. 2014;8(16):147. pmid:25125886
- 8. Majdalawieh AF, Massri M, Nasrallah GK. A comprehensive review on the anti-cancer properties and mechanisms of action of sesamin, a lignan in sesame seeds (Sesamum indicum). European Journal of Pharmacology. 2017;815:512–21. pmid:29032105
- 9. Majdalawieh AF, Mansour ZR. Sesamol, a major lignan in sesame seeds (Sesamum indicum): Anti-cancer properties and mechanisms of action. European journal of pharmacology. 2019;855:75–89. pmid:31063773
- 10. Jayaraj P, Narasimhulu CA, Rajagopalan S, Parthasarathy S, Desikan R. Sesamol: a powerful functional food ingredient from sesame oil for cardioprotection. Food & Function. 2020;11(2):1198–210. pmid:32037412
- 11.
Zhang H, Miao H, Ju M. Potential for adaptation to climate change through genomic breeding in sesame. Genomic designing of climate-smart oilseed crops: Springer; 2019. p. 371–440.
- 12. Troncoso‐Ponce MA, Kilaru A, Cao X, Durrett TP, Fan J, Jensen JK, et al. Comparative deep transcriptional profiling of four developing oilseeds. The Plant Journal. 2011;68(6):1014–27. pmid:21851431
- 13. Zhang H, Miao H, Li C, Wei L, Duan Y, Ma Q, et al. Ultra-dense SNP genetic map construction and identification of SiDt gene controlling the determinate growth habit in Sesamum indicum L. Scientific reports. 2016;6:31556. pmid:27527492
- 14. Yol E, Uzun B. Geographical patterns of sesame accessions grown under Mediterranean environmental conditions, and establishment of a core collection. Crop science. 2012;52(5):2206–14.
- 15. Jiao Y, Wang Y, Xue D, Wang J, Yan M, Liu G, et al. Regulation of OsSPL14 by OsmiR156 defines ideal plant architecture in rice. Nature genetics. 2010;42(6):541. pmid:20495565
- 16. Miao H, Li C, Duan Y, Wei L, Ju M, Zhang H. Identification of a Sidwf1 gene controlling short internode length trait in the sesame dwarf mutant dw607. Theor Appl Genet. 2020;133(1):73–86. pmid:31686114.
- 17. Mei H, Liu Y, Du Z, Wu K, Cui C, Jiang X, et al. High-density genetic map construction and gene mapping of basal branching habit and flowers per leaf axil in sesame. Frontiers in plant science. 2017;8:636. pmid:28496450
- 18. LI J-p Ali SA, Gui X CHEN F-j, YUAN L-x GU R-l. Phenotypic characterization and genetic mapping of the dwarf mutant m34 in maize. Journal of Integrative Agriculture. 2019;18(5):948–57.
- 19. Uzun B, Çağırgan Mİ. Comparison of determinate and indeterminate lines of sesame for agronomic traits. Field crops research. 2006;96(1):13–8.
- 20. Langham D. Progress in mechanizing sesame in the US through breeding. Trends in new crops and new uses. 2002.
- 21. Zhang H, Miao H, Wang L, Qu L, Liu H, Wang Q, et al. Genome sequencing of the important oilseed crop Sesamum indicumL. Genome biology. 2013;14(1):401. pmid:23369264
- 22. Srivastava P, Marker S, Pandey P, Tiwari D. Mutagenic effects of sodium azide on the growth and yield characteristics in wheat (Triticum aestivum L. em. Thell.). Asian Journal of Plant Sciences. 2011;10(3):190.
- 23. Jayabalan M. EMS induced variability in sesame. Crop Improvement. 1995.
- 24. Arslan Ç, Uzun B, Ülger S, İlhan Çağırgan M. Determination of oil content and fatty acid composition of sesame mutants suited for intensive management conditions. Journal of the American Oil Chemists’ Society. 2007;84:917–20.
- 25. Weldemichael MY, Baryatsion YT, Sbhatu DB, Gebresamuel Abraha G, Juhar HM, Kassa AB, et al. Effect of Sodium Azide on Quantitative and Qualitative Stem Traits in the M2 Generation of Ethiopian Sesame (Sesamum indicum L.) Genotypes. The Scientific World Journal. 2021;2021.
- 26. Teklu DH, Shimelis H, Tesfaye A, Mashilo J, Zhang X, Zhang Y, et al. Genetic variability and population structure of Ethiopian sesame (Sesamum indicum L.) germplasm assessed through phenotypic traits and simple sequence repeats markers. Plants. 2021;10(6):1129. pmid:34199342
- 27. Smith R, Grando M, Li Y, Seib J, Shatters R. Transformation of bahiagrass (Paspalum notatum Flugge). Plant cell reports. 2002;20(11):1017–21.
- 28. Degefa FT. Review on sesame (Sesamum indicum L.) breeding in Ethiopia. J Biol Agric Health. 2019;9(17):39–45.
- 29. Wang H, Zhang H, Ma Q, Wei L, Ju M, Li C, et al. Optimization of EMS mutagenesis condition and screening of mutants in sesame. J Henan Agri Sci. 2017;46(1):36–41.
- 30. Depei K, Lingbo Q, Xueyan Z, Ji L, Peng W, Fuguang L. Optimization of EMS Mutagenesis Condition and Screening of Mutants in Gossypium arboretum L. Cotton Science. 2017;29(4):336–44.
- 31. IPGRI N. Descriptors for sesame (Sesamum spp.). International Plant Genetic Resources Institute, Rome, Italy. 2004.
- 32. Payne R, Baird D, Cherry M, Gilmour A, Harding S, Lane P, et al. GenStat release 6.1 reference manual. Part 1. Summary. VSN International; 2002.
- 33. Duncan DB. Multiple range and multiple F tests. Biometrics. 1955;11(1):1–42.
- 34. Kang C. Breeding for diseases and shatter resistant high yielding varieties using induced mutations in sesame. Proceedings of the 2nd FAO/IAEA Res Coord Mtg, induced mutations for sesame improvement IAEA, Vienna. 1997:48–57.
- 35. Ashri A. Induced mutations in sesame breeding. 2001.
- 36. Wang L, Zhang Y, Zhu X, Zhu X, Li D, Zhang X, et al. Development of an SSR-based genetic map in sesame and identification of quantitative trait loci associated with charcoal rot resistance. Scientific reports. 2017;7(1):8349. pmid:28827730
- 37. RajaRamadoss B, Ganesamurthy K, Angappan K, Gunasekaran M. Mutagenic effectiveness and efficiency of gamma rays in sesame (Sesamum indicum L.). Global Journal of Molecular Sciences. 2014;9(1):01–6.
- 38. Lee J, Choi B. Progress and prospects of sesame breeding in Korea. Sesame and Safflower: Status and Potentials. 1985:137–44.
- 39. Pathirana R. Gamma ray‐induced field tolerance to Phytophthora blight in sesame. Plant Breeding. 1992;108(4):314–9.
- 40. Çağırgan Mİ. Selection and morphological characterization of induced determinate mutants in sesame. Field crops research. 2006;96(1):19–24.
- 41. Sander C, Kleinhofs A, Konzak C, Nillan R. Kinetic studies on the induction of the inhibition of repair of radiation damage in barley. Barley Genetic Newsletter. 1972;2:71.
- 42. Conger B. The effects of ascorbic acid and sodium azide on seedling growth of irradiated and non-irradiated barley seeds. Radiation Botany. 1973;13(6):375–9.
- 43. Konzak C, Niknejad M, Wickham I, Donaldson E. Mutagenic interaction of sodium azide on mutations induced in barley seeds treated with diethyl sulfate or N-methyl-N′-nitrosourea. Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis. 1975;30(1):55–61.
- 44. Wang L, Xia Q, Zhang Y, Zhu X, Zhu X, Li D, et al. Updated sesame genome assembly and fine mapping of plant height and seed coat color QTLs using a new high-density genetic map. BMC genomics. 2016;17(1):31. pmid:26732604
- 45. Li R, Bruneau A, Qu R. Morphological mutants of St. Augustinegrass induced by gamma ray irradiation. Plant Breeding. 2010;129(4):412–6.
- 46. Lu S, Wang Z, Niu Y, Chen Y, Chen H, Fan Z, et al. Gamma‐ray radiation induced dwarf mutants of turf‐type bermudagrass. Plant breeding. 2009;128(2):205–9.
- 47. Reynolds WC, Li R, de Silva K, Bruneau AH, Qu R. Field performance of mutant and somaclonal variation lines of St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze]. International Turfgrass Society Research Journal. 2009;11(573,582).
- 48. Mashenkov A. Induced mutation process as a source of new mutants. Maize Genetics cooperation newsletter. 1986;60:70–1.
- 49. Montalván R, Ando A. Effect of gamma-radiation and sodium azide on quantitative characters in rice (Oryza sativa L.). Genetics and molecular biology. 1998;21(1).
- 50. Ahloowalia B, Maluszynski M. Induced mutations–A new paradigm in plant breeding. Euphytica. 2001;118(2):167–73.