The effect of fatty acid profiles on peanut seed germination at low soil temperatures
Jungman, Brett S.
MetadataShow full item record
An experiment was set up to determine if altering the fatty acid composition would affect the germination of the peanut seed in cooler environments. Nine breeding lines of Dr. Olin Smith (deceased) were selected based on the oleic to linoleic acid (O/L) ratio. The lines (entries) were selected to give a range of oleic to linoleic (O/L) content that was classified as low (<3), medium (3-10), and high (>10), with Tamspan 90, a low O/L line, used as a control variety in the study. Germination percentage of entries were evaluated based on the O/L ratio, as well as the unsaturated to saturated (U/S) ratio. The unsaturated to saturated ratio was calculated by dividing the sum of oleic and linoleic acids by the sum of palmitic and stearic acids. These were not isogenic lines, so there may be other genetic traits, besides the fatty acid content, that were involved with germination differences. The lines were all of the Spanish type which is well adapted to the West Texas growing area. Fatty acid composition of the seed oil was measured on each of the selected lines by forming methyl esters of the oil and analyzing them by gas chromatography. Seeds were germinated in a controlled chamber at five different temperatures: an alternating 30°C for eight hours and 20°C for sixteen hours, and constant temperatures of 20°C, 18°C, 16°C, and 14°C. Germination counts were taken at 4, 10, and 12 days based on AOSA germination procedures for Spanish variety peanuts. Germination decreased as O/L and U/S ratios increased, especially at lower (16°C and 14°C) temperatures. This trend was not solely a factor of the O/L ratio, but also appeared to be related to the U/S ratio.