Peter, thank you for your reply and for pointing me to the work of P.T. Seaton and H.W.Pritchard. I managed to find a relevant paper from 2000 by P.T. Seaton, at this address:
<http://www.phytosophy.org/resources/Art001-En/Art001-En.html> The author cautions against overdrying as it may lead to a catastrophic decline in seed viability. This makes sense to me. The last few % of humidity probably consist of water molecules directly linked to proteins, polysaccharides, nucleic acids and lipid bilayers via hydrogen bonds. If you dehydrate these cell components their structure will be altered, perhaps irreversibly. That's why freeze-dried preparations of biological molecules use sucrose or trehalose, which are multiple hydrogen bond donors/acceptors and replace water as it evaporates. This paper includes an illustration of the desiccation method you describe, and mentions that a saturated solution of lithium chloride was also used with positive results. - Norbert _______________________________________________ the OrchidGuide Digest (OGD) orchids@orchidguide.com http://orchidguide.com/mailman/listinfo/orchids_orchidguide.com
