Fatty acid and elemental composition of mature seeds of beach pea [Lathyrus maritimus (L.) Bigel.]

This study was conducted to determine the fatty acid composition of phospholipids (PL), monoglycerides (MG), diglycerides (DG), free fatty acids (FFA) and triglycerides (TG) of mature beach pea seeds and the elemental composition of mature beach pea seed coats and embryos. In beach pea seeds, PL were dominated by C18:2 and C16:0 and MG contained high quantities of C18:2, C16:0 and C18:1. Diglycerides showed high C18:0, C16:0 and C18:2. Free fatty acids were dominated by C18:2, C16:0, C18:1 and C18:0, and TG were dominated by C18:1, C18:0 and C16:0. Energy dispersive X-ray microanalysis revealed K as the most abundant element in whole seed, seed coat and embryo. However, embryos showed significantly higher relative weight percentage of K than whole seeds and seed coats. Whole seeds and embryos contained higher P, S and Cl relative weight percentages than seed coats. Seed coats contained higher Ca, Na a nd Mg relative weight percentages than embryos. Aluminium, Si, Mn, Fe, Cu and Zn distribution between seed coat and embryo was uniform. Key words: Beach pea, element, fatty acid, Lathyrus maritimus L., lipid, seed

The pattern of seed development and maturation in beach pea (Lathyrus maritimus)

The developmental patterns of seed, seed coat, and hardseededness were studied in naturally growing crop plants of beach pea (Lathyrus maritimus (L.) Bigel.) at six reproductive growth stages (S1–S6). Grass pea (Lathyrus sativus L.) seeds were used for comparison in some experiments. The accumulation of fresh and dry weight in pod shell and seed of beach pea and pod shell of grass pea followed an almost sigmoidal pattern. However, grass pea seed showed a linear pattern of weight accumulation. During maturation, moisture content of pod shells and seeds decreased because of dehydration. Beach pea seeds were able to germinate precociously at S4. Seeds collected between S1 and S3 failed to germinate because of immaturity, whereas the development of hard seed coats prevented germination in seeds gathered at S5 and S6. An imbibition test revealed that hardseededness completely prevented water absorption of S5 and S6 seeds even after 24 days of soaking. In grass pea, precocious seed germination was observed at S3. However, speed of germination, germination percentage, seedling length and dry weight increased as seeds approached maturity. Lipid and protein accumulation in seeds of both species increased progressively with maturity and showed a positive correlation with seed weight accumulation. In both beach pea and grass pea seeds, S6 was identified as a physiological maturity stage.Key words: beach pea, grass pea, hard seed, imbibition, Lathyrus, seed coat, seed development, water impermeability.