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Research article
Jian Sun
Crop Research Institue, Jiangxi Academy of Agricultural Sciences, Nanchang, China
Corresponding Author
ORCiD: https://orcid.org/0000-0002-7443-179X
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background
Improvement in sesame (Sesamum indicum L.) drought tolerance at seedling stage is important for yield stability. Genetic approaches combing with conventional breeding is the most effective way to develop drought-tolerant cultivars. So far, only a few studies have been reported to reveal gene/ quantitative trait loci (QTL) controlling drought tolerance in sesame. To identify the genomic regions associated with drought tolerance, we constructed a high-density genetic map using a recombinant inbred line (RIL) population through whole genome re-sequencing (WGRS) technique. QTLs contributing to three seedling traits were identified under both non-stress and water stress conditions.
Results
Three drought tolerance related traits and their relative values (the ratio of value under stress to value under control condition), including seedling weight (SW), shoot length (SL) and root length (RL), were evaluated under control and PEG-induced osmotic conditions at seedling stage in a RIL population derived from cross of Zhushanbai (ZSB) and Jinhuangma (JHM). Significant variation and high broad sense heritability were observed for all traits except SW under stress condition in the population. With this population, a high-density linkage map with 1354 bin markers was constructed through WGRS strategy. Composite interval mapping analysis was performed for all the traits as well as their relative phenotypic data. A total of 34 QTLs were detected for these traits under both conditions and their relative values, and 13 stable QTLs associated with seven traits were revealed in two independent experiments, explaining on average, 4.95-16.26% of phenotypic variation for each QTL. Four of them contributed more than 10% of phenotypic variation. One region on chromosome 12 contained two major QTLs related to RL under osmotic condition and relative RL. Seven candidate genes underlying major QTLs for drought tolerance were identified according to gene descriptions and variations between parents.
Conclusion
The current study reports the first QTL mapping of drought tolerance related traits through a RIL population and first QTL detection of root related trait (root length) in sesame. These findings will provide new genetic resources for molecular improvement of drought tolerance and candidate gene identification in sesame.
Keywords
sesame, whole genome re-sequencing, bin-map, drought tolerance, QTL
Figure 1
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Figure 3
Figure 4
Figure 5
Figure 6
This is a list of supplementary files associated with this preprint. Click to download.
- SupplementalFigure1.docx
Additional file 1: Figure S1 The curves of LOD score (y-axis) for RSW, RSL and RRL across two independent experiments.
- TableS1.xlsx
Additional file 1: Table S1 Distribution of total filtered SNPs and InDels on 12 chromosomes
- TableS2.xlsx
Additional file 1: Table S2 The information of high-density bin map
- TableS3.xlsx
Additional file 1: Table S3 Putative candidate genes in the interval of major QTLs for drought tolerance
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A new preprint design is coming!
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This is a preprint, a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
Research article
Jian Sun
Crop Research Institue, Jiangxi Academy of Agricultural Sciences, Nanchang, China
Corresponding Author
ORCiD: https://orcid.org/0000-0002-7443-179X
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
History
CURRENT STATUS: Posted
Version 2
Posted 14 Oct, 2020
No community comments so far
No comments provided
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
Subject Areas
Plant Molecular Biology and Genetics
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background
Improvement in sesame (Sesamum indicum L.) drought tolerance at seedling stage is important for yield stability. Genetic approaches combing with conventional breeding is the most effective way to develop drought-tolerant cultivars. So far, only a few studies have been reported to reveal gene/ quantitative trait loci (QTL) controlling drought tolerance in sesame. To identify the genomic regions associated with drought tolerance, we constructed a high-density genetic map using a recombinant inbred line (RIL) population through whole genome re-sequencing (WGRS) technique. QTLs contributing to three seedling traits were identified under both non-stress and water stress conditions.
Results
Three drought tolerance related traits and their relative values (the ratio of value under stress to value under control condition), including seedling weight (SW), shoot length (SL) and root length (RL), were evaluated under control and PEG-induced osmotic conditions at seedling stage in a RIL population derived from cross of Zhushanbai (ZSB) and Jinhuangma (JHM). Significant variation and high broad sense heritability were observed for all traits except SW under stress condition in the population. With this population, a high-density linkage map with 1354 bin markers was constructed through WGRS strategy. Composite interval mapping analysis was performed for all the traits as well as their relative phenotypic data. A total of 34 QTLs were detected for these traits under both conditions and their relative values, and 13 stable QTLs associated with seven traits were revealed in two independent experiments, explaining on average, 4.95-16.26% of phenotypic variation for each QTL. Four of them contributed more than 10% of phenotypic variation. One region on chromosome 12 contained two major QTLs related to RL under osmotic condition and relative RL. Seven candidate genes underlying major QTLs for drought tolerance were identified according to gene descriptions and variations between parents.
Conclusion
The current study reports the first QTL mapping of drought tolerance related traits through a RIL population and first QTL detection of root related trait (root length) in sesame. These findings will provide new genetic resources for molecular improvement of drought tolerance and candidate gene identification in sesame.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
This is a list of supplementary files associated with this preprint. Click to download.
- SupplementalFigure1.docx
Additional file 1: Figure S1 The curves of LOD score (y-axis) for RSW, RSL and RRL across two independent experiments.
- TableS1.xlsx
Additional file 1: Table S1 Distribution of total filtered SNPs and InDels on 12 chromosomes
- TableS2.xlsx
Additional file 1: Table S2 The information of high-density bin map
- TableS3.xlsx
Additional file 1: Table S3 Putative candidate genes in the interval of major QTLs for drought tolerance
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