Location: Crop Genetics and Breeding ResearchTitle: Soil moisture affects fatty acids and oil quality parameters in peanut) Author
Submitted to: Journal of Plant Production Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/20/2014
Publication Date: 5/10/2014
Citation: Chaiyadee, S., Jogloy, S., Songsri, P., Singkham, N., Vorasoot, N., Sawatsitang, P., Holbrook Jr, C.C., Patanothai, A. 2014. Soil moisture affects fatty acids and oil quality parameters in peanut. Journal of Plant Production Science. 7:81-96. Interpretive Summary: Drought reduces yield of peanut, but its effect on oil quality (oleic and linoleic fatty acid compostion) is unknown. The objective of this study was to determine the effect of drought on oil quality. Six genotypes with varying levels of drought tolerance were grown under three levels of drought stress for two years. Drought stress resulted in improved oil quality due to an increase in oleic acid and a reduction in linoleic acid levels. Peanut genotypes with different levels of drought resistance displayed similar results in oil quality under drought conditions.
Technical Abstract: Drought affects yield of peanut, but its effect on oleic and linoleic acids that influence its oil quality of peanut genotypes with different levels of drought resistance has not been clearly investigated. Therefore, the aims of this research were to determine whether soil water levels could affect oil quality by changes in fatty acid compositions of peanut, and to investigate the changes in oil characters in peanut genotypes with their potential drought resistance under different water regimes. Field experiments were conducted in split-plot designs with four replications during dry season for two years (2003/04 and 2005/05). Three water regimes [field capacity (FC), 2/3 available soil water (2/3 AW) and 1/3 available soil water (1/3 AW)] were assigned as main-plots, and six peanut genotypes were assigned as sub-plots. The data were recorded at maturity for fatty acid compositions and % oil. The data were recorded at maturity for fatty acid compositions and % oil. Seed samples were analyzed for % oil by Soxtec System HT, and fatty acid composition were analyzed by gas liquid chromatography. Differences among water regimes and peanut genotypes were significant for oleic and linoleic acids content and their ratio (O/L ratio), unsaturated to saturated fatty acid ratio (U/S ratio) and iodine value (IV). Genotype x water regime interactions were also significant for all characters. Drought improved the oil quality by significant increase in oleic acid and O/L ratio, and reduced the linoleic acid, IV and U/S ratio. Peanut genotypes with different levels of drought resistance displayed similar tendency in fatty acid characters under drought conditions.