ABSTRACT
BACKGROUND: The transition from vegetative to reproductive growth is a key factor in yield maximization. Sesame (Sesamum indicum), an indeterminate short-day oilseed crop, is rapidly being introduced into new cultivation areas. Thus, decoding its flowering mechanism is necessary to facilitate adaptation to environmental conditions. In the current study, we uncover the effect of day-length on flowering and yield components using F 2 populations segregating for previously identified quantitative trait loci (Si_DTF QTL) confirming these traits. RESULTS: Generally, day-length affected all phenotypic traits, with short-day preceding days to flowering and reducing yield components. Interestingly, the average days to flowering required for yield maximization was 50 to 55 days, regardless of day-length. In addition, we found that Si_DTF QTL is more associated with seed-yield and yield components than with days to flowering. A bulk-segregation analysis was applied to identify additional QTL differing in allele frequencies between early and late flowering under both day-length conditions. Candidate genes mining within the identified major QTL intervals revealed two flowering-related genes with different expression levels between the parental lines, indicating their contribution to sesame flowering regulation. CONCLUSIONS: Our findings demonstrate the essential role of flowering date on yield components and will serve as a basis for future sesame breeding.
Subject(s)
Flowers , Quantitative Trait Loci , Sesamum , Sesamum/genetics , Sesamum/growth & development , Sesamum/physiology , Flowers/growth & development , Flowers/genetics , Flowers/physiology , Phenotype , PhotoperiodABSTRACT
Sesame is a major annual oil crop that is grown practically everywhere in tropical and subtropical Asia, as well as Africa, for its very nutritious and tasty seeds. Rising temperatures, droughts, floods, desertification, and weather all have a significant impact on agricultural production, particularly in developing countries like Ethiopia. Therefore, the main objective of this study is to examine the influence of climate change on the sesame yield in North Gondar, North Ethiopia, by using the autoregressive distributed Lag (ARDL) time series model. This study employed climate data from the Bahirdar Agrometeorological Center and secondary data on sesame production from the Ethiopian Statistical Service, spanning 36 years, from 1987 to 2023. Autoregressive Distributed LAG (ARDL) includes diagnostic tests for both short- and long-term autoregressive models. The results for the long-run and short-run elastic coefficients show a significant positive association between temperatures and sesame yield. Sesame yield and rainfall have a significant negative long-run and short-run relationship in North Gondar, North Ethiopia. ARDL results confirm that temperature and rainfall have significant effects on sesame productivity. Temperature had a considerable favorable effect on sesamen production, but rainfall had a negative effect in North Gondar, Ethiopia. Based on the evidence acquired from our study, we made several policy recommendations and suggestions to government officials, policymakers, new technologies, researchers, policy development planners, and other stakeholders in order to develop or implement new technology to halt its production and direct adaptation measures in light of the certainty of global warming and the characteristics of climate-dependent agricultural production.
Subject(s)
Climate Change , Sesamum , Ethiopia , Sesamum/growth & development , Sesamum/physiology , Rain , TemperatureABSTRACT
Weeds are the primary biotic constraint affecting sesame growth and production. Here, we applied EMS mutagenesis to an elite sesame cultivar and discovered a novel point mutation in the sesame SiALS gene conferring resistance to imidazolinone, a group of acetolactate-synthase (ALS)-inhibitors. The mutant line exhibited high resistance to imazamox, an ALS-inhibitor, with hybrid plants displaying an intermediate response. Field-based validation confirmed the mutant line's substantial resistance, leading to a significantly higher yield under imazamox treatment. Under pre-emergence application of imazapic, the mutant plants sustained growth, whereas wild-type and weed were effectively controlled. Field trials using s-metolachlor and imazapic combined resulted in weed-free plots compared to untreated controls. Consequently, this treatment showed a significantly greater yield (2280 vs. 880 Kg ha-1) than the commercial practice (s-metolachlor). Overall, our study unveils the potential of utilizing this point mutation in sesame breeding programs, offering new opportunities for integrated weed management strategies for sesame cultivation. Developing herbicide-resistant crop plants holds promise for supporting sustainable production and addressing the challenges of weed infestations in sesame farming.
Subject(s)
Herbicide Resistance , Herbicides , Sesamum , Weed Control , Weed Control/methods , Herbicide Resistance/genetics , Sesamum/genetics , Sesamum/growth & development , Herbicides/pharmacology , Acetolactate Synthase/genetics , Plant Weeds/genetics , Plant Weeds/drug effects , Plant Proteins/genetics , Plant Proteins/metabolism , Mutation , Crops, Agricultural/genetics , Crops, Agricultural/growth & developmentABSTRACT
The present investigation was framed to understand the genetics and development of conspicuous purple coloured corolla tip flower and multicapsules at axil in sesame (Sesamum indicum L.) from the cross between genotypes IC-205776 (â) 9 EC-118591 (â). The conspicuous corolla lip colour is recessive in expression and under digenic control, differing from the earlier reports. The ratio at F2 generation was best fit for 13:3 indicating inhibitory gene action for purple corolla lip colour. Among two genes, one acts as an inhibitory gene at recessive condition to produce conspicuous purple corolla lip colour. Multicapsules/axil is dominant in expression, controlled by more than one gene. The ratio of multiple capsules/axil and single capsules/axil at F2 generation was the best fit for the ratio 11:5 indicating dominance modification of duplicate genes for a number of capsules per axil. Single capsule/axil results due to dominance modification of duplicate genes where the homozygous condition of one gene reverses the dominance relation of another gene in heterozygous condition. Joint segregation analysis indicated independent segregation of corolla lip colour and capsule number per axil.
Subject(s)
Flowers/genetics , Sesamum/genetics , Color , Crosses, Genetic , Flowers/cytology , Flowers/growth & development , Fruit/genetics , Fruit/growth & development , Genotype , Pigmentation/genetics , Sesamum/growth & developmentABSTRACT
To achieve the nutritional target of human food, boron (B) has been described as an essential mineral in determining seed and theoretical oil yield of Sesamum indicum L. The research to increase its cultivation is garnering attention due to its high oil content, quality and its utilization for various purposes, which include human nutrition as well as its use in the food industry. For this, a two-year field experiment was performed at PAU, Punjab, India to determine the effect of different concentrations of foliar-applied B (20, 30 and 40 mg L-1) and different growth stages of crop, i.e., we measured the effects on agroeconomic indicators and certain quality parameters of sesame using different concentrations of B applied at the flowering and capsule formation stages as compared to using water spray and untreated plants. Water spray did not significantly affect the studied parameters. However, B application significantly increased the yield, uptake, antioxidant activity (AOA) and theoretical oil content (TOC) compared to those of untreated plants. The maximum increase in seed yield (26.75%), B seed and stover uptake (64.08% and 69.25%, respectively) as well as highest AOA (69.41%) and benefit to cost ratio (B:C ratio 2.63) was recorded when B was applied at 30 mg L-1 at the flowering and capsule formation stages. However, the maximum sesame yield and B uptake were recorded when B was applied at a rate of 30 mg L-1. A significant increase in TOC was also recorded with a B application rate of 30 mg L-1. For efficiency indices, the higher values of boron agronomic efficiency (BAE) and boron crop recovery efficiency (BCRE) were recorded when B was applied at 20 mg L-1 (5.25 and 30.56, respectively) and 30 mg L-1 (4.96 and 26.11, respectively) at the flowering and capsule formation stages. In conclusion, application of B @ 30 mg L-1 at the flowering and capsule formation stages seemed a viable technique to enhance yield, B uptake and economic returns of sesame.
Subject(s)
Agriculture/economics , Boron/metabolism , Plant Development , Sesamum/growth & development , Sesamum/metabolism , Algorithms , Chemical Phenomena , Minerals , Models, Economic , Models, Theoretical , Sesame Oil/analysis , Sesame Oil/chemistryABSTRACT
BACKGROUND: Unrevealing the genetic makeup of crop morpho-agronomic traits is essential for improving yield quality and sustainability. Sesame (Sesamum indicum L.) is one of the oldest oil-crops in the world. Despite its economic and agricultural importance, it is an 'orphan crop-plant' that has undergone limited modern selection, and, as a consequence preserved wide genetic diversity. Here we established a new sesame panel (SCHUJI) that contains 184 genotypes representing wide phenotypic variation and is geographically distributed. We harnessed the natural variation of this panel to perform genome-wide association studies for morpho-agronomic traits under the Mediterranean climate conditions. RESULTS: Field-based phenotyping of the SCHUJI panel across two seasons exposed wide phenotypic variation for all traits. Using 20,294 single-nucleotide polymorphism markers, we detected 50 genomic signals associated with these traits. Major genomic region on LG2 was associated with flowering date and yield-related traits, exemplified the key role of the flowering date on productivity. CONCLUSIONS: Our results shed light on the genetic architecture of flowering date and its interaction with yield components in sesame and may serve as a basis for future sesame breeding programs in the Mediterranean basin.
Subject(s)
Flowers/growth & development , Genome-Wide Association Study , Plant Stems/growth & development , Polymorphism, Single Nucleotide , Seeds/growth & development , Sesamum/growth & development , Sesamum/genetics , Crops, Agricultural/genetics , Crops, Agricultural/growth & development , Flowers/genetics , Genes, Plant , Genetic Variation , Genome, Plant , Genotype , Phenotype , Plant Stems/geneticsABSTRACT
Tuta absoluta is one of the most damaging pests of tomato crops worldwide. Damage due to larvae may cause up to 100% loss of tomato production. Use of natural enemies to control the pest, notably predatory mirids such as Nesidiocoris tenuis and Macrolophus pygmaeus, is increasingly being promoted. However, considering the potential damage caused to tomatoes by these omnivorous predators in the absence of T. absoluta, an alternative solution could be required to reduce tomato damage and improve the predators' performance. The use of companion plants can be an innovative solution to cope with these issues. The present study aimed to determine the influence of companion plants and alternative preys on the predators' performance in controlling T. absoluta and protecting tomato plants. We evaluated the effect of predators (alone or combined) and a companion plant (sesame (Sesamum indicum)) on T. absoluta egg predation and crop damage caused by N. tenuis. The influence of an alternative prey (Ephestia kuehniella eggs) on the spatial distribution of predators was also evaluated by caging them in the prey presence or absence, either on tomato or sesame plants or on both. We found that the presence of sesame did not reduce the efficacy of N. tenuis or M. pygmaeus in consuming T. absoluta eggs; hatched egg proportion decreased when N. tenuis, M. pygmaeus, or both predators were present. More specifically, this proportion was more strongly reduced when both predators were combined. Sesame presence also reduced necrotic rings caused by N. tenuis on tomato plants. Nesidiocoris tenuis preferred sesame over tomato plants (except when food was provided only on the tomato plant) and the upper part of the plants, whereas M. pygmaeus preferred tomato to sesame plants (except when food was provided only on the sesame plant) and had no preference for a plant part. Combination of predators N. tenuis and M. pygmaeus allows for better coverage of cultivated plants in terms of occupation of different plant parts and better regulation of T. absoluta populations. Sesamum indicum is a potential companion plant that can be used to significantly reduce N. tenuis damage to tomatoes.
Subject(s)
Heteroptera/physiology , Lepidoptera/pathogenicity , Sesamum/growth & development , Solanum lycopersicum/growth & development , Animals , Crops, Agricultural/growth & development , Crops, Agricultural/parasitology , Larva/physiology , Lepidoptera/parasitology , Solanum lycopersicum/parasitology , Pest Control, Biological , Plant Components, Aerial/growth & development , Plant Components, Aerial/parasitology , Predatory Behavior , Sesamum/parasitologyABSTRACT
Metagenomic analysis of food is becoming more routine and can provide important information pertaining to the shelf life potential and the safety of these products. However, less information is available on the microbiomes associated with low water activity foods. Pine nuts and sesame seeds, and food products which contain these ingredients, have been associated with recalls due to contamination with bacterial foodborne pathogens. The objective of this study was to identify the microbial community of pine nuts and sesame seeds using targeted 16S rRNA sequencing technology. Ten different brands of each seed type were assessed, and core microbiomes were determined. A total of 21 and 16 unique taxa with proportional abundances >1% in at least one brand were identified in the pine nuts and sesame seeds, respectively. Members of the core pine nut microbiome included the genera Alishewanella, Aminivibrio, Mycoplasma, Streptococcus, and unassigned OTUs in the families of Desulfobacteraceae and Xanthomonadaceae. For sesame seeds, the core microbiome included Aminivibrio, Chryseolina, Okibacterium, and unassigned OTUs in the family Flavobacteriaceae. The microbiomes of these seeds revealed that these products are dominated by environmental bacterial genera commonly isolated from soil, water, and plants; bacterial genera containing species known as commensal organisms were also identified. Understanding these microbiomes can aid in the risk assessment of these products by identifying food spoilage potential and community members which may co-enrich with foodborne bacterial pathogens.
Subject(s)
Microbiota , Pinus/microbiology , Sesamum/microbiology , Alteromonadaceae/genetics , Alteromonadaceae/isolation & purification , Nuts/microbiology , Pinus/growth & development , Principal Component Analysis , RNA, Ribosomal, 16S/genetics , Seeds/microbiology , Sesamum/growth & development , Streptococcus/genetics , Streptococcus/isolation & purificationABSTRACT
BACKGROUND: Owing to fluctuations of international market prices and excess supply during peak harvesting seasons, farmers and traders often suffer from a low market price of sesame. Such a negative impact can be ameliorated by taking advantage of times with a better market price during the off season. This study aimed to investigate the impact of different storage containers on gravimetric properties and germination capacities of five different sesame varieties as well as their impact on Indian meal moth (Plodia interpunctella). RESULTS: There were differences among the types of storage containers in terms of moisture content, oil content, thousand seed weight, and germination capacity with the storage duration. However, in terms of bulk density, true density, and porosity, the results were consistent. On average, a few losses in thousand seed weight for varieties stored in Purdue Improved Crop Storage bags (1.7%), metal silos (2.4%), and GrainPro bags (3.4%) were observed during 12 months' storage compared with polypropylene bags (17%). The difference among sesame varieties in terms of weight loss and loss of webbing due to P. interpunctella varied with storage duration. On average, about 9.4% weight loss and 5.7% loss due to webbing was measured for seed stored in polypropylene bags due to the natural infestation of P. interpunctella. No pest was found in hermetic containers. CONCLUSION: In general, to fetch better market prices, the use of hermetic storage is more efficient to maintain the desired gravimetric properties and to prevent losses due to P. interpunctella infestation compared with the commonly used woven polypropylene bags. © 2020 Society of Chemical Industry.
Subject(s)
Food Packaging/instrumentation , Moths/physiology , Seeds/growth & development , Sesame Oil/chemistry , Sesamum/parasitology , Animals , Ethiopia , Food Storage , Germination , Seeds/chemistry , Seeds/parasitology , Sesamum/chemistry , Sesamum/growth & developmentABSTRACT
Genetic dissection of yield components and seed mineral-nutrient is crucial for understanding plant physiological and biochemical processes and alleviate nutrient malnutrition. Sesame (Sesamum indicum L.) is an orphan crop that harbors rich allelic repertoire for seed mineral-nutrients. Here, we harness this wide diversity to study the genetic architecture of yield components and seed mineral-nutrients using a core-collection of worldwide genotypes and segregating mapping population. We also tested the association between these traits and the effect of seed nutrients concentration on their bio-accessibility. Wide genetic diversity for yield components and seed mineral-nutrients was found among the core-collection. A high-density linkage map consisting of 19,309 markers was constructed and used for genetic mapping of 84 QTL associated with yield components and 50 QTL for seed minerals. To the best of our knowledge, this is the first report on mineral-nutrients QTL in sesame. Genomic regions with a cluster of overlapping QTL for several morphological and nutritional traits were identified and considered as genomic hotspots. Candidate gene analysis revealed potential functional associations between QTL and corresponding genes, which offers unique opportunities for synchronous improvement of mineral-nutrients. Our findings shed-light on the genetic architecture of yield components, seed mineral-nutrients and their inter- and intra- relationships, which may facilitate future breeding efforts to develop bio-fortified sesame cultivars.
Subject(s)
Chromosomes, Plant/genetics , Minerals/metabolism , Nutrients/metabolism , Plant Breeding , Quantitative Trait Loci , Seeds/chemistry , Sesamum/genetics , Chromosome Mapping , Minerals/analysis , Nutrients/analysis , Sesamum/growth & development , Sesamum/metabolismABSTRACT
Sesame is an important oil-crop worldwide. Complex tradeoffs between various yield components significantly affect the outcome yield. Our aims were to characterize the effect of genotype, environment and management, and their interactions, on yield components. Wild-type line, bearing a bicarpellate-capsule and three capsules per leaf axil, and its derived mutant-line, featuring one tetracarpellate-capsule per leaf axil, were analyzed under two irrigation regimes and three sowing-stands. Dissection of flower meristems and capsules showed larger placenta size and final capsule diameter in the mutant-line. Allelic segregation of F2 population revealed that the number of carpels per capsule demonstrates monogenic inheritance, whereas the number of capsules per leaf axil is a polygenic trait. A significant effect of genotype, irrigation and stand was observed on most yield components. While wild-type had more capsules per plant, the mutant-line compensated by increased seed number per capsule and consequently accumulated the same number of seeds per plant. Under either high intra-row or inter-row density, the branches number was reduced; however, the outcome yield was compensated by number of plants per area. While some yield components showed phenotypic-plasticity (branching), other traits were genetically stable (number of capsules per leaf axil and number of carpels per capsule). Our result shed-light on tradeoffs between yield components and on their underlying mechanisms.
Subject(s)
Crop Production , Gene-Environment Interaction , Genotype , Sesamum/growth & development , Climate Change , Sesamum/geneticsABSTRACT
BACKGROUND: Both photosynthetic pigments and chloroplasts in plant leaf cells play an important role in deciding on the photosynthetic capacity and efficiency in plants. Systematical investigating the regulatory mechanism of chloroplast development and chlorophyll (Chl) content variation is necessary for clarifying the photosynthesis mechanism for crops. OBJECTIVE: This study aims to explore the critical regulatory mechanism of leaf color mutation in a yellow-green leaf sesame mutant Siyl-1. METHODS: We performed the genetic analysis of the yellow-green leaf color mutation using the F2 population of the mutant Siyl-1. We compared the morphological structure of the chloroplasts, chlorophyll content of the three genotypes of the mutant F2 progeny. We performed the two-dimensional gel electrophoresis (2-DE) and compared the protein expression variation between the mutant progeny and the wild type. RESULTS: Genetic analysis indicated that there were 3 phenotypes of the F2 population of the mutant Siyl-1, i.e., YY type with light-yellow leaf color (lethal); Yy type with yellow-green leaf color, and yy type with normal green leaf color. The yellow-green mutation was controlled by an incompletely dominant nuclear gene, Siyl-1. Compared with the wild genotype, the chloroplast number and the morphological structure in YY and Yy mutant lines varied evidently. The chlorophyll content also significantly decreased (P < 0.05). The 2-DE comparison showed that there were 98 differentially expressed proteins (DEPs) among YY, Yy, and yy lines. All the 98 DEPs were classified into 5 functional groups. Of which 82.7% DEPs proteins belonged to the photosynthesis and energy metabolism group. CONCLUSION: The results revealed the genetic character of yellow-green leaf color mutant Siyl-1. 98 DEPs were found in YY and Yy mutant compared with the wild genotype. The regulation pathway related with the yellow leaf trait mutation in sesame was analyzed for the first time. The findings supplied the basic theoretical and gene basis for leaf color and chloroplast development mechanism in sesame.
Subject(s)
Chlorophyll/genetics , Mutation , Photosynthesis/genetics , Plant Leaves/metabolism , Plant Proteins/analysis , Proteome/analysis , Sesamum/metabolism , Chloroplasts , Chromosome Mapping , Chromosomes, Plant , Color , Gene Expression Regulation, Plant , Phenotype , Plant Leaves/genetics , Plant Leaves/growth & development , Plant Proteins/genetics , Plant Proteins/metabolism , Sesamum/genetics , Sesamum/growth & developmentABSTRACT
BACKGROUND: Sesame (Sesamum indicum L., 2n = 2x = 26) is an important oilseed crop with high oil content but small seed size. To reveal the genetic loci of the quantitative seed-related traits, we constructed a high-density single nucleotide polymorphism (SNP) linkage map of an F2 population by using specific length amplified fragment (SLAF) technique and determined the quantitative trait loci (QTLs) of seed-related traits for sesame based on the phenotypes of F3 progeny. RESULTS: The genetic map comprised 2159 SNP markers distributed on 13 linkage groups (LGs) and was 2128.51 cM in length, with an average distance of 0.99 cM between adjacent markers. QTL mapping revealed 19 major-effect QTLs with the phenotypic effect (R2) more than 10%, i.e., eight QTLs for seed coat color, nine QTLs for seed size, and two QTLs for 1000-seed weight (TSW), using composite interval mapping method. Particularly, LG04 and LG11 contained collocated QTL regions for the seed coat color and seed size traits, respectively, based on their close or identical locations. In total, 155 candidate genes for seed coat color, 22 for seed size traits, and 54 for TSW were screened and analyzed. CONCLUSIONS: This report presents the first QTL mapping of seed-related traits in sesame using an F2 population. The results reveal the location of specific markers associated with seed-related traits in sesame and provide the basis for further seed quality traits research.
Subject(s)
Chromosomes, Plant , Sesamum/genetics , Amplified Fragment Length Polymorphism Analysis , Chromosome Mapping/methods , Genetic Markers , Genotype , Phenotype , Polymorphism, Single Nucleotide , Quantitative Trait Loci , Seeds/genetics , Sesamum/growth & developmentABSTRACT
BACKGROUND: Sesame (Sesame indicum L.) is well-known as a versatile industrial crop having various usages and contains 50-55% oil, 20% protein, 14-20% carbohydrate and 2-3% fiber. Several environmental factors are known to adversely affect yield and productivity of sesame. Our overall aim was to improve the growth, yield and quality of sesame cv. TS-3 using plant growth promoting rhizobacteria (PGPR) and saving the nitrogen and phosphate fertilizers (NP) by 50%. Field experiment (randomized complete block design) was conducted during the months of July to October of two consecutive years 2012-2013. Azospirillum (AL) and Azotobacter (AV) were applied as seed inoculation alone as well as along with half of the recommended dose of nitrogen (N) and phosphate (P) fertilizers (urea and diammonium phosphate) at the rate of 25 kg/ha and 30 kg/ha respectively. RESULTS: Here we report that A. lipoferum along with half dose of NP fertilizers (ALCF) were highly effective in increasing the agronomic and yield traits of sesame as compared to the control. A. vinelandii plus NP fertilizers (AVCF) exhibited higher seed oil content. Minimum acid value, optimum specific gravity and modified fatty acid composition were observed in ALCF treatment. Increase in oleic acid by ALCF is directly linked with improved oil quality for health benefits as oleic acid is the fatty acid which creates a balance between saturation and unsaturation of oil and for the hypotensive (blood pressure reducing) effects. CONCLUSION: It is inferred that ALCF treatment improved plant growth, seed yield and oil quality of sesame pertaining to good quality edible oil production.
Subject(s)
Azospirillum lipoferum/chemistry , Azotobacter vinelandii/chemistry , Nutritive Value , Sesame Oil/analysis , Sesamum/chemistry , Sesamum/growth & development , Fertilizers/analysis , Phosphates/analysis , Random Allocation , Urea/analysisABSTRACT
MAIN CONCLUSION: Sesame harbors a large diversity in root morphological and anatomical traits and a high root biomass improves the plant aboveground biomass as well as the seed yield. Sesame provides one of the most nutritious and healthy vegetable oils, sparking an increasing demand of its seeds. However, with the low yield and productivity of sesame, there is still a huge gap between the seed demand and supply. Improving the root system has a high potential to increase crop productivity, but information on the diversity of the sesame root systems is still lacking. In this study, 40 diverse sesame varieties were grown in soil and hydroponics systems and the diversity of the root system was investigated. The results showed that sesame holds a large root morphological and anatomical diversity, which can be harnessed in breeding programmes. Based on the clustering of the genotypes in hydroponics and soil culture systems, we found that similar genotypes were commonly clustered either in the small-root or in the big-root group, indicating that the hydroponics system can be employed for a large-scale root phenotyping. Our results further revealed that the root biomass positively contributes to increased seed yield in sesame, based on multi-environmental trials. By comparing the root transcriptome of two contrasting genotypes, 2897 differentially expressed genes were detected and they were enriched in phenylpropanoid biosynthesis, starch and sucrose metabolism, stilbenoid, diarylheptanoid and gingerol biosynthesis, flavonoid biosynthesis, suggesting that these pathways are crucial for sesame root growth and development. Overall, this study sheds light on the diversity of sesame root system and offers the basis for improving root traits and increasing sesame seed yield.
Subject(s)
Sesamum/genetics , Transcriptome , Biomass , Genotype , Phenotype , Plant Oils/metabolism , Plant Proteins/genetics , Plant Roots/anatomy & histology , Plant Roots/genetics , Plant Roots/growth & development , Sesamum/anatomy & histology , Sesamum/growth & developmentABSTRACT
BACKGROUND: Sesame is a major oilseed crop which is widely cultivated all around the world. Flowering, the timing of transition from vegetative to reproductive growth, is one of the most important events in the life cycle of sesame. Sesame is a typical short-day (SD) plant and its flowering is largely affected by photoperiod. However, the flowering mechanism in sesame at the molecular level is still not very clear. Previous studies showed that the CONSTANS (CO) gene is the crucial photoperiod response gene which plays a center role in duration of the plant vegetative growth. RESULTS: In this study, the CO-like (COL) genes were identified and characterized in the sesame genome. Two homologs of the CO gene in the SiCOLs, SiCOL1 and SiCOL2, were recognized and comprehensively analyzed. However, sequence analysis showed that SiCOL2 lacked one of the B-box motifs. In addition, the flowering time of the transgenic Arabidopsis lines with overexpressed SiCOL2 were longer than that of SiCOL1, indicating that SiCOL1 was more likely to be the potential functional homologue of CO in sesame. Expression analysis revealed that SiCOL1 had high expressed levels before flowering in leaves and exhibited diurnal rhythmic expression in both SD and long-day (LD) conditions. In total, 16 haplotypes of SiCOL1 were discovered in the sesame collections from Asia. However, the mutated haplotypes did not express under both SD and LD conditions and was regarded as a nonfunctional allele. Notably, the sesame landraces from high-latitude regions harboring nonfunctional alleles of SiCOL1 flowered much earlier than landraces from low-latitude regions under LD condition, and adapted to the northernmost regions of sesame cultivation. The result indicated that sesame landraces from high-latitude regions might have undergone artificial selection to adapt to the LD environment. CONCLUSIONS: Our results suggested that SiCOL1 might contribute to regulation of flowering in sesame and natural variations in SiCOL1 were probably related to the expansion of sesame cultivation to high-latitude regions. The results could be used in sesame breeding and in broadening adaptation of sesame varieties to new regions.
Subject(s)
Flowers/growth & development , Genes, Plant/physiology , Plant Proteins/physiology , Sesamum/growth & development , Transcription Factors/physiology , Arabidopsis , Conserved Sequence/genetics , Flowers/physiology , Gene Expression Regulation, Plant , Genes, Plant/genetics , Haplotypes , Photoperiod , Phylogeny , Plants, Genetically Modified , Real-Time Polymerase Chain Reaction , Sesamum/genetics , Sesamum/physiology , Transcription Factors/geneticsABSTRACT
Sesame is poised to become a major oilseed crop owing to its high oil quality and adaptation to various ecological areas. However, the seed yield of sesame is very low and the underlying genetic basis is still elusive. Here, we performed genome-wide association studies of 39 seed yield-related traits categorized into five major trait groups, in three different environments, using 705 diverse lines. Extensive variation was observed for the traits with capsule size, capsule number and seed size-related traits, found to be highly correlated with seed yield indexes. In total, 646 loci were significantly associated with the 39 traits (p < 10-7) and resolved to 547 quantitative trait loci QTLs. We identified six multi-environment QTLs and 76 pleiotropic QTLs associated with two to five different traits. By analyzing the candidate genes for the assayed traits, we retrieved 48 potential genes containing significant functional loci. Several homologs of these candidate genes in Arabidopsis are described to be involved in seed or biomass formation. However, we also identified novel candidate genes, such as SiLPT3 and SiACS8, which may control capsule length and capsule number traits. Altogether, we provided the highly-anticipated basis for research on genetics and functional genomics towards seed yield improvement in sesame.
Subject(s)
Quantitative Trait Loci , Seeds/genetics , Sesamum/genetics , Chromosome Mapping , Gene Expression Regulation, Plant , Genetic Linkage , Genome, Plant , Genome-Wide Association Study , Phenotype , Seeds/anatomy & histology , Seeds/growth & development , Sesamum/anatomy & histology , Sesamum/growth & developmentABSTRACT
Soil co-contamination with lead (Pb) and cadmium (Cd) is a tenacious risk to crop production globally. The current experiment observed the roles of amendments [biochar (BC), slag (SL), and ferrous manganese ore (FMO)] for enhancing Pb and Cd tolerance in sesame (Sesamum indicum L.). Our results revealed that application of amendments significantly enhanced the nutrient level of sesame seedlings developed under extreme Pb and Cd conditions. The higher Pb and Cd-tolerance in sesame encouraged by amendments might be credited to its capability to restrict Pb and Cd uptake and decreased oxidative damage induced by Pb and Cd that is also demonstrated by lesser production of hydrogen peroxide (H2O2), malondialdehyde (MDA), and reduced electrolyte leakage (EL) in plant biomass. The added amendments relieved Pb and Cd toxicity and improved photosynthetic pigments, soluble protein, and proline content. Not only this amendments also decreased the antioxidant bulk, such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in sesame plants compared to control when exposed to Pb and Cd. Moreover, the added amendmentsâ¯=â¯down-regulated the genes expression which regulate the SOD, POD, and CAT activity in sesame under Pb and Cd-stress. Furthermore, supplementation of amendments to the soil, reduced the bio accessibility (SBET), leachability (TCLP), and mobility (CaCl2) of Pb and Cd. Collectively, our findings conclude that the application of amendments enhanced sesame tolerance to Pb and Cd stress by restricting Pb and Cd accumulation, maintained photosynthetic presentation and dropped oxidative loss through enhanced antioxidant system, thus signifying amendments as an operational stress regulators in modifying Pb and Cd-toxicity that is highly important economically in all crops including sesame.
Subject(s)
Cadmium/toxicity , Charcoal/pharmacology , Environmental Pollution , Lead/toxicity , Sesamum/growth & development , Sesamum/metabolism , Soil/chemistry , Antioxidants/metabolism , Biomass , Calcium Chloride/chemistry , Electric Conductivity , Gene Expression Regulation, Plant/drug effects , Hydrogen Peroxide/metabolism , Hydrogen-Ion Concentration , Malondialdehyde/metabolism , Photosynthesis/drug effects , Pigments, Biological/metabolism , Plant Leaves/drug effects , Plant Leaves/metabolism , Seedlings/drug effects , Seedlings/growth & development , Sesamum/drug effects , Sesamum/genetics , Soil Pollutants/toxicity , Spectroscopy, Fourier Transform Infrared , Stress, Physiological/drug effectsABSTRACT
BACKGROUND: As an important oil crop, growth habit of sesame (Sesamum indicum L.) is naturally indeterminate, which brings about asynchronous maturity of capsules and causes loss of yield. RESULTS: The genetic basis of determinate growth habit in sesame was investigated by classical genetic analysis through multiple populations, results revealed that it was controlled by an unique recessive gene. The genotyping by sequencing (GBS) approach was employed for high-throughput SNP identification and genotyping in the F2 population, then a high density bin map was constructed, the map was 1086.403 cM in length, which consisted of 1184 bins (13,679 SNPs), with an average of 0.918 cM between adjacent bins. Based on bin mapping in conjunction with SSR markers analysis in targeted region, the novel sesame determinacy gene was mapped on LG09 in a genome region of 41 kb. CONCLUSIONS: This study dissected genetic basis of determinate growth habit in sesame, constructed a new high-density bin map and mapped a novel determinacy gene. Results of this study demonstrate that we employed an optimized approach to get fine-accuracy, high-resolution and high-efficiency mapping result in sesame. The findings provided important foundation for sesame determinacy gene cloning and were expected to be applied in breeding for cultivars suited to mechanized production.
Subject(s)
Plant Breeding , Sesamum/growth & development , Sesamum/genetics , Chromosome Mapping/methods , Genes, Plant , Genetic Linkage , Polymorphism, Single NucleotideABSTRACT
Three iridoids (lamalbid (I1), sesamoside (I2) and shanzhiside methyl ester (I3)) and seven polyphenols (cistanoside F (P1), chlorogenic acid (P2), pedalitin-6-O-laminaribioside (P3), pedaliin (P4), isoacteoside (P6), pedalitin (P7) and martynoside (P8)) were identified in young sesame leaves (Sesamum indicum L.) other than the acteoside (P5) reported previously. P3 was a new compound, and I1, I3, P2 and P8 were found in a species of Sesamum for the first time. HPLC analyses revealed that the compounds I1 (0.29-1.75% of dry leaves), I2 (0.38-0.87%), I3 (0.04-1.07%), P4 (0.01-2.05%) and P5 (0.13-4.86%) were present primarily in young sesame leaves and were found in plants cultivated on different farms (plant height, 30-70 cm). Of the identified compounds, P5 and P6 showed high 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, oxygen radical absorbance capacity (ORAC), and in vitro antiglycation activities. Given its content, P5 makes a major contribution to the biological activities of young sesame leaves. The compounds were examined at six different growth stages of plants cultured in a greenhouse to determine the optimum harvest stage and for end-use assessment. P5 accumulated in the leaves during growth, and the content reached a maximum of 12.9% of dry leaves in the 4th stage (plant height, 74.5±9.7 cm), which is one of the highest percentages reported in plants from nature.