Poster: Seed biology

Abs # 708: Long living lotus (Nelumbo nucifera, China Antique): biomechanical and biochemical properties of pericarps and cotyledons in old (380 and 544 y) and new fruits

Presenter:	Jane, Shen-Miller , shenmiller@biology.ucla.edu
Authors	Jane, Shen-Miller  (A)   Allen, Murray K. (B)   Louis, Aung H. (C)   Jeff, Turek R. (D)
Affiliations:	(A): Univ CA, Los Angeles (B): Glycozyme, Inc., Irvine, CA (C): Posharvest Quality & Genetics Res Unit, USDA-ARS, Parlier, CA (D): Hysitron, Inc., Minneapolis, MN

Lotus holds the world's record of seed viability, 1300 y. Its seamless pericarp prevents entry of water, air, and infestation. The penetration force of the coat by Instron is ~105 Newton, similar to that of coconut. The hardness and reduced modulus of the pericarp measured by nanoindentation is respectively, 0.06 and 1.97 GPa (giga Pascal). Carbohydrate analyses yield inositol, arabinose, glucose & fructose (cold-water extract), same in hot-water and weak-acid extracts except no arabinose. No differences, qualitative or quantitative, are found in old & new coats including the acetic-nitric acid (ANA)-soluble fraction. However, differences in quantity do occur in hydrolysates of ANA-insoluble fractions of old & new coats. In cotyledons, the quantitative difference in ratios of oligosaccharides of old & new seeds in all fractions suggest interconversions during aging. Acid hydrolysis of an ANA-soluble fraction yields rhamnose, arabinose, galactose, glucose & mannose. Alcohol-soluble, cold & hot water-extractable sugars are stachyose, sucrose, raffinose, some verbascose & fructose, additionally, inositol & glucose in water extracts (more in old than in new seeds). The coat properties and the possible vitreous sugars in seeds may contribute to lotus longevity and germination.