Title: Variation in seed lipids in Calendula germplasm Authors
Submitted to: Association for the Advancement of Industrial Crops Conference
Publication Type: Abstract Only
Publication Acceptance Date: July 1, 2011
Publication Date: September 11, 2011
Citation: Widrlechner, M.P., Isbell, T. 2011. Variation in seed lipids in Calendula germplasm [abstract]. In: Johnson, B.L. and Berti, M.T., editors. 23rd Annual Association for the Advancement of Industrial Crops Meeting-Challenges and Opportunities for Industrial Crops: Program and Abstracts, September 11-14, 2011, Fargo, North Dakota. p. 47. Technical Abstract: Calendula officinalis (pot marigold) has considerable promise as an industrial crop, with a long history as an ornamental and medicinal plant. It is also marketed as an ingredient in cosmetics and a colorant. It produces unusual seed lipids, which can provide an additional market for commercial Calendula producers. More than 80 Calendula accessions, including wild relatives, have been assembled at the North Central Regional Plant Introduction Station (NCRPIS). The objective of our study was to sample all available Calendula seedlots, primarily grown at the NCRPIS, but including some lots received from other sources for comparison, with a goal to document variation in seed-oil percentage and fatty-acid composition. We extracted 88 samples and used pulsed NMR to determine total oil percent on a dry weight basis. Fatty acid methyl esters were made from the seeds with 0.5M sodium methoxide and anaylzed by gas chromatography. Our Calendula samples generally were low in total seed oil at 5.7 to 16.5%, due in part to their extensive seed coats. However, the primary fatty acid was the unusual omega-6 compound, calendic acid, at 31.7 to 67.8% of total seed oil. In five comparisons between paired samples of accessions grown at the NCRPIS with those grown elsewhere, four NCRPIS samples displayed 6.3 to 15.7% lower proportions of calendic acid, compensated by increases in linoleic and/or oleic acids. Wild Calendula species often presented fatty-acid profiles beyond values found among 40 C. officinalis samples. For example, the highest proportion of calendic acid (67.8%) was found in C. maroccana, linoleic acid (39.6%) in C. arvensis, and oleic acid (24.0%) in C. stellata. These wild taxa may be useful in breeding Calendula cultivars with modified fatty-acid profiles.