Development, fatty acid composition, and storage of drupes and seeds from the endangered pondberry (Lindera melissifolia)
Pondberry (Lindera melissifolia [Walt.] Blume: Lauraceae) is an endangered, dioecious, clonal shrub that grows in bottomland hardwood forests in the southeastern United States. Prior work has emphasized vegetative reproduction associated with the clonal nature of this species. Little has been published about the early morphological and biochemical characteristics of the fruit as they mature. Fruits, drupes originating from the axillary buds, were collected every 30 days after anthesis and examined for seed structure development and fatty acid composition of the fruit and seed. Sixty days after anthesis, fruits had not formed an organized embryo/cotyledon, weighed 0.1 i 0.001 g, and measured 7.1 * 0.04 mm x 4.3 * 0.03 mm. Ninety days after anthesis, a complete seed had formed within the drupe. Of the total drupe weight (average 0.23 i 0.01 g), the seed comprised 33% of the mass gained from 60 days after anthesis. Overall composition of the seed and pulp lipids changed significantly over the course of development. Myristic, palmitic, steric, oleic, linoleic, and linoleic fatty acids were revealed by the lipid analyses. Lauric acid was not found in any of the early seed lipid samples but it increased in quantity as seed matured to become the dominant fatty acid in this tissue. Conversely, pulp contained only small amounts of lauric acid; its fatty acid profile was dominated by oleic acid. Fully hydrated seeds stored well for 16 months at both 4 oC and -2 oC. Although drying had a deleterious effect on germination when dried seeds were conventionally stored at 4 oC, seeds that had been dried for 24 h to a moisture content of 8.6% were successfully stored in liquid nitrogen.