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ARS Home » Southeast Area » Griffin, Georgia » Plant Genetic Resources Conservation Unit » Research » Publications at this Location » Publication #312149

Research Project: Conservation, Characterization, and Evaluation of Plant Genetic Resources and Associated Information

Location: Plant Genetic Resources Conservation Unit

Title: Variation in Seed Fatty Acid Composition, and Sequence Divergence in the FAD2 Gene Coding Region between Wild and Cultivated Sesame

Author
item Chen, Zhenbang - University Of Georgia
item Tonnis, Brandon
item Morris, John - Brad
item Wang, R - University Of Georgia
item Zhang, Amy - University Of Georgia
item Pinnow, David
item Wang, Ming

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/11/2014
Publication Date: 11/11/2014
Citation: Chen, Z., Tonnis, B.D., Morris, J.B., Wang, R.B., Zhang, A., Pinnow, D.L., Wang, M.L. 2014. Variation in Seed Fatty Acid Composition, and Sequence Divergence in the FAD2 Gene Coding Region between Wild and Cultivated Sesame. Journal of Agricultural and Food Chemistry. 62:11706-11710.

Interpretive Summary: Sesame germplasm harbors genetic diversity which can be useful for sesame improvement in breeding programs. Seven accessions with different levels of oleic acid were selected from the entire USDA sesame germplasm collection and planted for morphological observation and re-examination of fatty acid composition. The coding region of the FAD2 gene for fatty acid desaturase in these accessions was also sequenced. Cultivated sesame accessions flowered and matured earlier than the wild species. The cultivated sesame seeds contained a significantly higher percentage of oleic acid (40.4%) than the seeds of the wild species (26.1%). Nucleotide polymorphisms were identified in the FAD2 gene coding region between wild and cultivated species. Some nucleotide polymorphisms led to amino acid changes, one of which was located in the enzyme active site and may contribute to the altered fatty acid composition. Based on the morphology observation, chemical and sequence analysis, it was determined that two accessions were misnamed and need to be reclassified. The results obtained from this study are useful for sesame improvement in molecular breeding programs.

Technical Abstract: Sesame germplasm harbors genetic diversity which can be useful for sesame improvement in breeding programs. Seven accessions with different levels of oleic acid were selected from the entire USDA sesame germplasm collection (1232 accessions) and planted for morphological observation and re-examination of fatty acid composition. The coding region of the FAD2 gene for fatty acid desaturase (FAD) in these accessions was also sequenced. Cultivated sesame accessions flowered and matured earlier than the wild species. The cultivated sesame seeds contained a significantly higher percentage of oleic acid (40.4%) than the seeds of the wild species (26.1%). Nucleotide polymorphisms were identified in the FAD2 gene coding region between wild and cultivated species. Some nucleotide polymorphisms led to amino acid changes, one of which was located in the enzyme active site and may contribute to the altered fatty acid composition. Based on the morphology observation, chemical and sequence analysis, it was determined that two accessions were misnamed and need to be reclassified. The results obtained from this study are useful for sesame improvement in molecular breeding programs.