High Stearic Acid Research Articles

Inheritance of Palmitic and Stearic Acid Mutants of Soybean

Soybean [Glycine max (L.) Merr.] cultivars with increased levels of palmitic or stearic acid in the seed oil could reduce the need for chemical modifications during processing for some vegetable oil products. Mutants with altered levels of the fatty acids were developed by artificial mutagenesis with ethyl methane sulfonate (EMS). Four of the mutants had 128 to 182 g kg−1 palmitic acid compared with 90 to 100 g kg−1 in their parents, and four mutants had 132 to 301 g kg−1 stearic acid compared with 33 to 51 g kg−1 in their parents. The objective of this study was to determine the inheritance of palmitic or stearic acid in the seed oil of the eight mutants. Reciprocal crosses were made between each mutant and the cultivar Coles, among three of the palmitic mutants, and between the high‐stearic acid line A6 and the four stearic mutants. Fatty acid analysis of the parents and F1, F2, and F3 generations indicated that the allele controlling low palmitic and low stearic acid in Coles exhibited partial dominance to the alleles in PA1, PA2, PA3, ST1, ST2, ST3, and ST4 and no dominance to the allele in PA4. The crosses between A6 and the stearic mutants indicated that the alleles controlling high stearic acid in ST1, ST3, and ST4 occurred at the same locus as the fasa allele in A6 and that the allele in ST2 may occur at a different locus. Significant maternal and cytoplasmic effects on palmitic and stearic acid content were not confirmed in any of the mutants.

Association of Alleles for High Stearic Acid with Agronomic Characters of Soybean1

Alleles that control four to sevenfold increases in the content of stearic acid in soybean [Glycine max (L.) Merr.] oil have been obtained by artificial mutagenesis. The objective of this study was to evaluate the association of three alleles for high stearic acid with agronomic and chemical characters of soybean. Three mutant lines, A6 with 282 g kg−1 stearic acid, A9 with 163 g kg−1 stearic acid, and A10 with 146 g kg−1 stearic acid, each with a different allele at a single locus controlling stearic acid content in the seed oil, were crossed to one of three high‐yielding genotypes with stearic acid content of about 40 g kg−1. The F1 plants of each mating were backcrossed without selection to the high‐yielding parent. Pairs of highand low‐stearic‐acid lines were selected from BC1F2‐derived lines segregating for a high‐stearic‐acid allele. The pairs of lines were evaluated in a replicated test at three Iowa locations. There were no significant differences in the average yield of the high‐ and the low‐stearic‐acid lines from the A9 and A10 crosses. In the A6 cross, the low‐stearic‐acid lines had significantly greater seed yield than high‐stearic‐acid lines by an average of 7.7%. For the other characters measured, the maximum differences between the mean performance of high‐ and low‐stearic‐acid lines for any of the three crosses were 2.9 days for time of maturity, 4 cm for plant height, 0.3 units for lodging score, 8 mg seed−1 for seed weight, 13 g kg−1 for seed protein, and 1 g kg−1 for seed oil. The stearic acid contents of the BC1F3‐derived lines generally were less than those of their donor parent, which indicated that modifying genes may influence this character.

Inheritance of Three Stearic Acid Mutants of Soybean1

Three mutant lines of soybean [Glycine max (L.) Merrill] were identified that had three‐ to six‐fold increases in stearic acid content in the seed oil compared with their parents. Our objective was to determine the inheritance of high stearic acid in the three mutants. Reciprocal crosses were made between each mutant and its parent and among the three mutants. Fatty acid analysis of the seed oil of the parents and the F1, F2, and F3 generations indicated that high stearic acid in the mutants was controlled by a single locus. The Fas allele for low stearic acid in each parent was partially dominant to the allele for high stearic acid in the mutant derived from it. Crosses among the mutants indicated that each possessed a different allele at the same locus. The allele fasa, in the mutant A6, and fas6, in the mutant FA41545, were not dominant to each other. Both fasa and fasb were completely dominant to thefas allele in the mutant A81‐606085. None of the segregates from the mutant ✕ mutant crosses had a stearic acid content outside the range of the parents. Maternal and cytoplasmic effects were not important in the control of stearic acid content in these mutants.

Fatty acid development in a soybean mutant with high stearic acid

AbstractThe fatty acid composition of developing soybean (Glycine max [L.] Merrill) seeds was evaluated in the mutant line, A6, and its parent, FA8077. Seeds of both lines were harvested at 2‐day intervals from 15 to 39 days after flowering (DAF) and at 4‐day intervals from 39 DAF until maturity. Significant differences between the two lines were observed for stearic and oleic acid percentages at 19 DAF. The maximum difference between the lines was at 25 DAF, when A6 had 45.4% and FA8077 had 4.1% stearic acid. The increase in stearic acid percentage in A6 was accompanied by a decrease in oleic acid to 16.8% at 25 DAF, compared with 53.7% oleic acid for FA8077. The two lines did not differ in development of palmitic, linoleic and linolenic acids. The protein and oil content of mature seeds were similar for the two lines.

Fatty acid composition of oil synthesized by Aspergillus nidulans.

The filamentous fungus Aspergillus nidulans Eidam strain 300 was found to be capable of synthesizing 24.9% oil or remarkably low free fatty acidity, in a chemically defined medium with 34% glucose as sole carbon source. although the total content of oil synthesized was less, utilization of the carbon source is better as shown by the high (8.4) fat coefficient. The major component fatty acids of the oil were palmitic, stearic, oleic and linoleic and are influenced by the source of carbon. Palmitoleic acid is present in traces, confirming thereby the general observation that high oil formers produce oil of low hexadecenoic acid content. The relatively high stearic acid content of the oil distinguishes it from those of other microorganisms and resembles the oil produced by certain tropical plants, such as Madhuca latifolia.

Intravenous Infusions Into Human Subjects of Fractionated Coconut Oil Emulsions

Summary1. Emulsions of the glycerides of the short chain fatty acids were toxic when injected intravenously into human subjects.2. The glycerides of the high molecular weight fatty acids, lauric, myristic, palmitic and stearic acids were non-toxic when injected jin emulsion form. 3. Inclusion with the latter of small concentrations of the fatty acid esters of the type of oleic and linoleic acids did not affect the toxicity of the emulsions.