Submitted to: Plant Genetic Resources: Characterization and Utilization
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/24/2014
Publication Date: 4/1/2015
Citation: Seiler, G.J. 2015. Comparison of fatty acid composition of oil from original and regenerated populations of wild Helianthus species. Plant Genetic Resources: Characterization and Utilization. 13(1):83-89. DOI:10.1017/S1479262114000677.
Interpretive Summary: Plant genetic resources management comprises several phases including germplasm collection and maintenance. Collection is the first step to gather the germplasm into the genebank for safe keeping. The next important step is to maintain the genetic integrity in the germplasm collection. This is a priority when regenerating populations for increasing seeds for distribution. The wild sunflower germplasm collection is stored and maintained at the USDA Agricultural Research Service, North Central Regional Plant Introduction Station, Ames, IA. Fatty acid composition of sunflower oil is an important quality factor for the sunflower crop. Several accessions have been evaluated for fatty acid composition of the oil. These evaluations were performed on the oil from seeds from the original populations. Since we know that fatty acids in sunflower are environmentally influenced, we designed a study to evaluate the fatty acid composition in populations that had been regenerated for seed increase in the routine maintenance of the collection. The largest number of populations of a species examined was from the wide ranging common wild annual sunflower. This species had a significant decrease in palmitic and stearic acids, and an increase in oleic acid, and no change in linoleic acid for the regenerated populations compared to the original populations. For the perennial species evaluated, only Nuttall’s sunflower had a significant increase in oleic and significant decrease in linoleic acids between the original and regenerated populations. It appears that selection for specific fatty acids in oil of certain species will require analyzing both the original and regenerated populations before determining which populations should be utilized in a selection and breeding program.
Technical Abstract: Monitoring and protecting germplasm in genebanks using in situ collections while preserving its original genetic integrity is a priority of germplasm curation. Many germplasm accessions need to be regenerated from seed due to demand and/or seed condition. The regeneration of wild Helianthus species poses several challenges due to the diversity of the 52 species. Fatty acid composition of sunflower oil is an important quality factor for the crop. Since oil quality is environmentally influenced, and evaluation for this trait is usually performed on oil from achenes from the original populations of wild sunflowers, a study was conducted on 72 accessions of eight annual and four perennial taxa of wild sunflowers to compare oil quality of original vs. accessions regenerated for genebank maintenance. From the study, it was apparent that the differences in fatty acid composition between achenes from the original and the regenerated accessions are not equivalent. It appears that selection for a specific fatty acid in certain species will require analyzing both populations to identify germplasm for use in breeding programs. One thing to keep in mind is that wild species accessions are open-pollinated segregating populations, so one would expect a certain amount of variability in each of the succeeding generations. While there may be differences between the original and regenerated accessions, the trend is similar to other wild and cultivated sunflower, so selections from either would be suitable for breeding. As more regenerated populations become available to evaluate, a more precise relationship between original and regenerated accessions will emerge.