Tags

Type your tag names separated by a space and hit enter

Genotypic effect of ahFAD2 on fatty acid profiles in six segregating peanut (Arachis hypogaea L) populations.
BMC Genet. 2013 Jul 17; 14:62.BG

Abstract

BACKGROUND

Fatty acid composition of oil extracted from peanut (Arachis hypogaea L.) seed is an important quality trait because it may affect the flavor and shelf life of resulting food products. 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. Functional mutations, G448A in ahFAD2A and 442insA in ahFAD2B eliminate or knock down desaturase activity and have been demonstrated to produce peanut oil with high O/L ratios. In order to employ marker assisted selection (MAS) to select a high oleic disease resistant peanut and to evaluate genotypic and phenotypic variation, crosses were made between high oleic (~80%) and normal oleic (~50%) peanuts to produce segregating populations.

RESULTS

A total of 539 F2 progenies were randomly selected to empirically determine each ahFAD2 genotype and the resulting fatty acid composition. Five of the six crosses segregated for the high oleic trait in a digenic fashion. The remaining cross was consistent with monogenic segregation because both parental genotypes were fixed for the ahFAD2A mutation. Segregation distortion was significant in ahFAD2A in one cross; however, the remaining crosses showed no distortion. Quantitative analyses revealed that dominance was incomplete for the wild type allele of ahFAD2, and both loci showed significant additive effects. Oleic and linoleic acid displayed five unique phenotypes, based on the number of ahFAD2 mutant alleles. Further, the ahFAD2 loci did exhibit pleiotropic interactions with palmitic (C16:0), oleic (C18:1), linoleic (C18:2) acids and the O/L ratio. Fatty acid levels in these progeny were affected by the parental genotype suggesting that other genes also influence fatty acid composition in peanut. As far as the authors are aware, this is the first study in which all of the nine possible ahFAD2 genotypes were quantitatively measured.

CONCLUSIONS

The inheritance of the high oleic trait initially was suggested to be controlled by dominant gene action from two homoeologous genes (ahFAD2A and ahFAD2B) exhibiting complete recessivity. Analyzing the ahFAD2 genotypes and fatty acid compositions of these segregating peanut populations clearly demonstrated that the fatty acid contents are quantitative in nature although much of the variability in the predominant fatty acids (oleic, linoleic, and palmitic) is controlled by only two loci.

Links

PMC Free PDF
PMC Free Full Text
FREE Publisher Full Text

Authors+Show Affiliations

Barkley NA
USDA ARS Plant Germplasm Resources Conservation Unit, 1109 Experiment Street, Griffin, GA 30223, USA. Elle.Barkley@ars.usda.gov
Isleib TG
No affiliation info available
Wang ML
No affiliation info available
Pittman RN
No affiliation info available

MeSH

AnimalsArachisBase SequenceDNA PrimersFatty Acid DesaturasesFatty AcidsGenotypeNematodaPhenotypePolymerase Chain Reaction

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

23866023

Citation

Barkley, Noelle A., et al. "Genotypic Effect of ahFAD2 On Fatty Acid Profiles in Six Segregating Peanut (Arachis Hypogaea L) Populations." BMC Genetics, vol. 14, 2013, p. 62.
Barkley NA, Isleib TG, Wang ML, et al. Genotypic effect of ahFAD2 on fatty acid profiles in six segregating peanut (Arachis hypogaea L) populations. BMC Genet. 2013;14:62.
Barkley, N. A., Isleib, T. G., Wang, M. L., & Pittman, R. N. (2013). Genotypic effect of ahFAD2 on fatty acid profiles in six segregating peanut (Arachis hypogaea L) populations. BMC Genetics, 14, 62. https://doi.org/10.1186/1471-2156-14-62
Barkley NA, et al. Genotypic Effect of ahFAD2 On Fatty Acid Profiles in Six Segregating Peanut (Arachis Hypogaea L) Populations. BMC Genet. 2013 Jul 17;14:62. PubMed PMID: 23866023.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Genotypic effect of ahFAD2 on fatty acid profiles in six segregating peanut (Arachis hypogaea L) populations. AU - Barkley,Noelle A, AU - Isleib,Thomas G, AU - Wang,Ming Li, AU - Pittman,Roy N, Y1 - 2013/07/17/ PY - 2012/11/07/received PY - 2013/06/28/accepted PY - 2013/7/20/entrez PY - 2013/7/20/pubmed PY - 2013/10/18/medline SP - 62 EP - 62 JF - BMC genetics JO - BMC Genet VL - 14 N2 - BACKGROUND: Fatty acid composition of oil extracted from peanut (Arachis hypogaea L.) seed is an important quality trait because it may affect the flavor and shelf life of resulting food products. 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. Functional mutations, G448A in ahFAD2A and 442insA in ahFAD2B eliminate or knock down desaturase activity and have been demonstrated to produce peanut oil with high O/L ratios. In order to employ marker assisted selection (MAS) to select a high oleic disease resistant peanut and to evaluate genotypic and phenotypic variation, crosses were made between high oleic (~80%) and normal oleic (~50%) peanuts to produce segregating populations. RESULTS: A total of 539 F2 progenies were randomly selected to empirically determine each ahFAD2 genotype and the resulting fatty acid composition. Five of the six crosses segregated for the high oleic trait in a digenic fashion. The remaining cross was consistent with monogenic segregation because both parental genotypes were fixed for the ahFAD2A mutation. Segregation distortion was significant in ahFAD2A in one cross; however, the remaining crosses showed no distortion. Quantitative analyses revealed that dominance was incomplete for the wild type allele of ahFAD2, and both loci showed significant additive effects. Oleic and linoleic acid displayed five unique phenotypes, based on the number of ahFAD2 mutant alleles. Further, the ahFAD2 loci did exhibit pleiotropic interactions with palmitic (C16:0), oleic (C18:1), linoleic (C18:2) acids and the O/L ratio. Fatty acid levels in these progeny were affected by the parental genotype suggesting that other genes also influence fatty acid composition in peanut. As far as the authors are aware, this is the first study in which all of the nine possible ahFAD2 genotypes were quantitatively measured. CONCLUSIONS: The inheritance of the high oleic trait initially was suggested to be controlled by dominant gene action from two homoeologous genes (ahFAD2A and ahFAD2B) exhibiting complete recessivity. Analyzing the ahFAD2 genotypes and fatty acid compositions of these segregating peanut populations clearly demonstrated that the fatty acid contents are quantitative in nature although much of the variability in the predominant fatty acids (oleic, linoleic, and palmitic) is controlled by only two loci. SN - 1471-2156 UR - https://www.unboundmedicine.com/medline/citation/23866023/Genotypic_effect_of_ahFAD2_on_fatty_acid_profiles_in_six_segregating_peanut__Arachis_hypogaea_L__populations_ L2 - https://bmcgenet.biomedcentral.com/articles/10.1186/1471-2156-14-62 DB - PRIME DP - Unbound Medicine ER -