抄録
Changes in lipid components during soybean seed (Glycine max.) development were studied to clarify differences in lipid accumulation among three cultivars (Harosoy 63, Enrei and Koitozairai) and also among the individual parts of a seed (cotyledon, hypocotyl and seed coat).
1. Changes in the lipid components of the three cultivars. The dates of flowering and lengths of maturation periods differed among the three cultivars even though they were all planted on the same day. The weight of a hundred seeds and lipid content also differed. Differences in lipid accumulation and in changes of fatty acid composition, sterol content in lipid, and sterol composition among the three cultivars were essentially the same. The cultivars all showed similar accumulation patterns of lipid components, except tocopherol.
2. Changes in the lipid components of cotyledon, hypocotyl and seed coat.
(a) Cotyledon : In each case, this part showed a lipid accumulation patterns similar to that of the whole seed and nearly the entire lipid content of the seed was present in the cotyledon.
(b) Hypocotyl : The lipid content of this part reached a constant level in the early stage of seed development. The ratio of cis-vaccenic acid to oleic acid was greater in this part than in cotyledon. α-Tocopherol content in the lipid component became quite high in the late stage of seed development. Sterol content in lipid and the percentage of sitosterol were higher in hypocotyl than in cotyledon. They showed little change during seed development.
(c) Seed coat : This part showed the complicated changes in fatty acid composition and the ratio of cis-vaccenic acid to oleic acid was high. Sterol content in the lipid was also high.
Based on the results of the present study, it became clear that lipid composition and its changes during seed development differ considerably for each part of a seed.
