Acid Content In Soybean Research Articles

Genetic Variation for Modifiers Controlling Reduced Saturated Fatty Acid Content in Soybean

Soybean [Glycine max (L.) Merr.] oils with reduced palmitic acid concentrations should comply with U.S. Food and Drug Administration (FDA) regulations for vegetable oils with lower saturated fatty acid contents. This study was designed to investigate the genetic basis for reduced palmitic and stearic acid contents in the seed oil of reduced palmitic add germplasm, N87-2122-4. Crosses between N87-2122-4 and Midwest-adapted cultivars, Kenwood and P9273, revealed frequencies of reduced and normal palmitic acid among F 2 progeny consistent with segregation at a single major locus. There was a large phenotypic variation (15-30 g kg -1 ) for palmitic acid content measured on progeny homozygous for either reduced or normal palmitic acid alleles, however. Repeatability of this variation was examined in 87 reduced and normal palmitic F 5:7 lines randomly sampled from each cross. Reduced palmitic acid lines ranged between 54 and 72 g kg -1 , and normal palmitic acid lines between 90 and 119 g kg -1 for both crosses. No line produced significantly less palmitic acid than N87-2122-4 but 55% of the reduced palmitic acid lines were significantly greater (P 80%) for palmitic and stearic acid contents suggest that total saturates may be reduced by selection in few environments for major and modifier genes controlling reduced palmitic acid content.

Inheritance of reduced linolenic acid content in soybean seed oil

Linolenic acid is the unstable component of soybean [Glycine max (L.) Merr.] oil that is responsible for the undesirable odors and flavors commonly associated with poor oil quality. Two mutants, M-5 and KL-8, have been identified that have lower linolenic acid levels in the seed oil than the ‘Bay’ cultivar. Our objective was to determine the relationships between the genetic systems controlling linolenic acid in these mutants. Reciprocal crosses were made between the mutants and ‘Bay’, and between the two mutants. No maternal effect for linolenic acid content was observed from the analysis of F1 seeds in any of the crosses. The data for linolenic acid content in F2 seeds of M-5בBay’ and KL-8בBay’ crosses satisfactorily fit a 1 : 2 : 1 and 3 : 1 ratio, respectively. For the M-5×KL-8 cross, segregation observed from the analysis of F2 seeds for linolenic acid content satisfactorily fit a ratio of 3 more than either mutant: 12 within the range of the two mutants: 1 less than either mutant. The segregation ratio of F2 seeds and the segregation of F3 seeds from F2 plants indicated that M-5 and KL-8 have alleles at different loci that control linolenic acid content. The allele in KL-8 has been designated as fanx (KL-8) to distinguish it from fan (M-5). The low linolenic acid segregates with the genotype fanfanfanxfanx provide additional germplasm to reduce the linolenic acid content from the seed oil of soybean.

Phenotypic variation for saturated fatty acid content in soybean

Concern over high saturates in human diets has prompted the development of soybean [Glycine max (L.) Merr.] lines producing oil with reduced saturated fatty acid concentration. To better understand those factors that influence phenotypic expression for palmitic and stearic acid content in soybean, thirty soybean lines random for saturated fatty acid content were grown in eight field environments contrasting for mean temperature during seed-filling. Palmitic and stearic acid content varied significantly (P<0.01) both among genotypes and across environments, while genotype x environment interactions were reflected in changes in line variance and ranking for both traits. Therefore selection of a superior genotype for saturated fatty acid composition may not correlate well from one environment to another. In general, early-maturing lines were less sensitive than later-maturing lines in their response to changes in mean daily temperature for palmitic concentration. However, factors in addition to temperature appeared to influence genotype response for stearic acid content. It appears that genetic systems conditioning palmitic and stearic acids are independent, and that separate breeding strategies need be adopted to make simultaneous improvement for these two oil traits. In summary, development of soybean lines with low or high saturated fatty acid content may be accomplished through evaluation and selection in a few environments contrasting for temperature.

Interactions between stem termination type and linolenic acid content in soybean

Three determinate (dt1/dt1) soybean (Glycine max (L.) Merr.) lines: Hoyt, HC 80-1742 and HC 80-1756, with a "standard" linolenic acid content (Fan/Fan) were crossed to the indeterminate (dt1/dt1), "low" linolenic acid (fan/fan) line G-LLA-F3. The F2 plants descended from these crosses were grown in the field at Harrow in 1988 and the F2:3 plants were grown at Harrow and Ridgetown, Ontario in 1989. In the F2 progeny, the mean linolenic acid content of the determinate plants was not different from the mean of the indeterminate plants for the "standard" class (8.5 and 8.6%) or for the "low" class (4.1 and 4.2%). In the F2:3 progeny, for the "standard" class, the determinate plants (9.4%) had a significantly (P &lt; 0.05) higher mean linolenic acid content than the indeterminate plants (9.1%). For the "low" class, the mean linolenic acid content of the determinate plants (4.9%) was significantly (P &lt; 0.05) lower than the mean of the indeterminate plants (5.2%) at Ridgetown, but was not different (4.7 and 4.7%) at Harrow. The differences in linolenic acid content between stem types were less than the differences between lines or between locations. Overall, there was no pattern associated with stem termination type and linolenic acid content for soybean plants grown in short season areas. Key words: Soybean, Glycine max (L.) Merr., determinate, indeterminate, linolenic acid

Linolenic Acid Content in Soybean Improved by X-Ray Irradiation

Linolenic Acid Content in Soybean Improved by X-Ray Irradiation

Linolenic acid content in soybean improved by X-ray irradiation.

Dry seeds of soybean [Glycine max (L.) Merr. cv. Bay] were irradiated with X-rays (21.4 kR) and the M2 progeny was evaluated for linolenic acid (18:3) content in the oil. A significant amount of genetic variability was observed for linolenic acid content in the oil of Bay cultivar after X-ray irradiation compared with the control. Out of 3,000 M2 plants, a mutant was identified, M923, in which the linolenic acid content accounted for 4.4 percent, about half the amount of the original variety. An inverse relationship between linoleic acid and linolenic acid contents was observed. The mutant M923 always had lower linolenic acid content in different environmental conditions in the M3 generation.

Inheritance of oleic and linolenic acid in soybean seeds.

The experiment was carried out to make clear the inheritance of oleic acid and linolenic acid content in soybean seed oil. The materials used were cultivar Orihime (P1) and Matsuura (P2) as parents and their hybrid populations i. e. F1, F2, B1 and B2. The partitioning method developed by POWERS Was applied. The parental varieties were supposed to differ by two gene pairs. Namely, Orihime (P1) was symbolized as AAbb having 44.0% of oleic acid content, so was Matsuura (P2) as aaBB having 51.5%, and F1 as AaBb having 45. 6%. The mean and standard deviation for single determination were estimated in the population of AABb and Aabb in B1, AaBB and aaBb in B2, AABB and aabb in F2, A good fitness was found between observed and expected frequency distributions for oleic acid content in B1, F2 and B2 populations, hence these data supported the hypothesis of genotypes mentioned above. These two pairs of genes are controlling oleic acid content additively with a slight partial dominance towards low content. AABB expresses lower content of oleic acid of 32.7%, and aabb higher content of 56.6%. Application of the method of HAYMAN showed that the action of additive genes was more important than that of dominance gene. Significant additive by dominance epistasis was also recognized. A negative correlation was found between oleic acid and linoleic acid content (r=-0.988). It might be suggested that the same genes are controlling contents of both oleic and linoleic acid.