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ARS Home » Southeast Area » Griffin, Georgia » Plant Genetic Resources Conservation Unit » Research » Publications at this Location » Publication #312412
Title: The complex tale of the high oleic acid trait in peanut (Arachis hypogaea L.)

Author
item Anglin, Noelle
item KLEVORN, C - NORTH CAROLINA STATE UNIVERSITY
item Hendrix, Keith
item Dean, Lisa

Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/11/2014
Publication Date: 1/10/2015
Citation: Barkley, N.L., Klevorn, C.M., Hendrix, K., Dean, L.L. 2015. The complex tale of the high oleic acid trait in peanut (Arachis hypogaea L.). Plant and Animal Genome Conference Proceedings. Paper No. 16750.

Interpretive Summary: Fatty acid composition of oil extracted from peanut (Arachis hypogaea L.) seed is an important quality trait. In particular, a high ratio of oleic (C18:1) relative to linoleic (C18:2) fatty acid (O/L = 10) results in a longer shelf life. Previous reports suggest that the high oleic (~80%) trait was controlled by recessive alleles of ahFAD2A and ahFAD2B, the former of which is thought to have a high frequency in US runner- and virginia-type cultivars. Markers were developed to detect the genotypes to aid in marker assisted breeding. Genotyping and phenotyping of crosses made between high and normal oleic peanuts demonstrated that dominance was incomplete and both loci showed significant additive effects. Analyzing the ahFAD2 genotypes and fatty acid compositions of these segregating peanut populations clearly demonstrated that the fatty acid contents are quantitative in nature. Segregation and characterization of the normal and high oleic seeds is important for breeding programs to develop high oleic lines and in processing of food products for the peanut industry. Mixtures in high oleic cultivars has been increasing; therefore, more research has been ongoing to determine the source of the contamination. Utilizing the developed markers to genotype individual seed lots produced from F7 lines in a breeding program demonstrated a lack of purity for ahFAD2 genotypes suggesting that more generations may be necessary to achieve pure lines. Further, individual seeds from single high oleic peanut plants have been analyzed and found to have a range of oleic phenotypes indicating that maturity plays a significant role in the oil composition of peanut. The collected data has shown that maintaining pure high oleic seed lots will be more difficult than previously imagined.

Technical Abstract: Fatty acid composition of oil extracted from peanut (Arachis hypogaea L.) seed is an important quality trait. In particular, a high ratio of oleic (C18:1) relative to linoleic (C18:2) fatty acid (O/L = 10) results in a longer shelf life. Previous reports suggest that the high oleic (~80%) trait was controlled by recessive alleles of ahFAD2A and ahFAD2B, the former of which is thought to have a high frequency in US runner- and virginia-type cultivars. Markers were developed to detect the genotypes to aid in marker assisted breeding. Genotyping and phenotyping of crosses made between high and normal oleic peanuts demonstrated that dominance was incomplete and both loci showed significant additive effects. Analyzing the ahFAD2 genotypes and fatty acid compositions of these segregating peanut populations clearly demonstrated that the fatty acid contents are quantitative in nature. Segregation and characterization of the normal and high oleic seeds is important for breeding programs to develop high oleic lines and in processing of food products for the peanut industry. Mixtures in high oleic cultivars has been increasing; therefore, more research has been ongoing to determine the source of the contamination. Utilizing the developed markers to genotype individual seed lots produced from F7 lines in a breeding program demonstrated a lack of purity for ahFAD2 genotypes suggesting that more generations may be necessary to achieve pure lines. Further, individual seeds from single high oleic peanut plants have been analyzed and found to have a range of oleic phenotypes indicating that maturity plays a significant role in the oil composition of peanut. The collected data has shown that maintaining pure high oleic seed lots will be more difficult than previously imagined.