Inheritance of Oleic and Linolenic Acid in Soybean Seeds

Abstract

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.