Oil concentration and fatty acid profile of naturalized wild annual Helianthus annuus populations from Australia

Authors: Seiler, Gerald; GULYA, THOMAS - Retired ARS Employee; KONG, GARY - University Of Canberra; THOMPSON, SUE - University Of Southern Queensland; MITCHELL, JEFFERY - Queensland Department Of Primary Industries & Fisheries

Submitted to: Genetic Resources and Crop Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/21/2018
Publication Date: 9/4/2018
Citation: Seiler, G.J., Gulya, T., Kong, G., Thompson, S., Mitchell, J. 2018. Oil concentration and fatty acid profile of naturalized wild annual Helianthus annuus populations from Australia. Genetic Resources and Crop Evolution. https://doi.org/10.1007/s10722-018-0686-6.
DOI: https://doi.org/10.1007/s10722-018-0686-6

Interpretive Summary: Collection and the preservation of crop wild relatives (CWR) of important crop species such as sunflower provide the basic foundation to promote and sustain the crop, and are the biological basis of global food security. Management of sunflower CWR encompasses several different phases including germplasm collection, maintenance, and evaluation. Collection is the first step to gather the wild sunflowers and put them into the genebank for safe keeping. The next important step is to maintain the genetic integrity of the germplasm. The third step is to evaluate the germplasm for biotic and abiotic traits for the improvement of the sunflower crop. Sunflower is one of the few native USA crops originating in the Mississippi River Valley in the vicinity of present-day Arkansas. Over time, the sunflower CWR have become naturalized in other parts of the world. Their translocation put them in a different environment, so one might logically expect them to adapt to their local environment. Since wild annual sunflower was naturalized in Australia, it would be interesting to see if the oil content and quality, important traits of the cultivated sunflower has changed during naturalization, and if they differ in oil content and quality from their native progenitors in the eastern USA. The populations of wild annual sunflower from Australia did not differ from their native ancestors in oil content and quality. While the oil content of the Australian populations was half that of the cultivated sunflower, the oil quality was similar. Based on this fact, there should be little concern about the lower oil content of these naturalized crop wild relatives when used as a source for other unique traits, such as disease resistance, salt tolerance, and insect resistance for cultivated sunflower improvement.

Technical Abstract: While wild annual sunflower (Helianthus annuus L.) is indigenous to North America, it has been inadvertently and intentionally introduced into countries, such as Australia, where they have become naturalized. Prior to this research, there were no collections of naturalized wild annual H. annuus sunflower from Australia in the USDA National Plant Germplasm System gene bank. Since this species has been naturalized in Australia, the possibility exists that it may contain distinct traits such as oil content and fatty acid composition differing from their North American progenitors due to the different environments, diseases, and insect pest complexes. The objective of the study was to collect wild naturalized H. annuus populations from the five states of Australia and to analyze them for oil content and fatty acid composition. Fifty-six populations were collected throughout the broad distributional range of the wild annual species and analyzed for oil content and fatty acid composition. The mean oil content of the wild H. annuus populations was 28%, ranging from a low of 19% to a high of 31%, similar to populations of this wild species collected in its native habitat. Fatty acid profiles were also similar for the native, naturalized wild and cultivated sunflower. Oil concentration of interspecific hybrids can be rapidly increased to acceptable levels by backcrossing with cultivated sunflower. Based on this fact, there should be little concern about the lower oil content of this wild species when it is used as a source of other unique traits for cultivated sunflower improvement.