8:	The Charms of Duckweed.

Authors:	Cross, John, W.(A)
Affiliations:	(A): Universities Space Research Association
Presenter:	Cross, John W., jwcross@usra.edu

The duckweeds (Lemnaceae) are the smallest flowering plants. Researchers have used these plants to study plant biochemistry, plant development, photosynthesis, phytotoxicology, and much more. Duckweeds find application in bioremediation and aquaculture. I like to call the duckweeds "The Other Model System." Duckweeds have many recognized advantages as a model system: ease of handling, rapid growth, ability to absorb chemicals from their medium directly into the plant thallus, growth in liquid medium without physical supports, low contents of fiber and enzyme inhibitors. Most of regulatory and develomental pathways of higher plants are available for study: induction of flowering, development of floral organs, phytochrome regulation, induction and breaking of dormancy, hormonally regulated development, etc. Duckweed genetics has not been thoroughly studied, but inbred lines have been developed and mutations have been identified and studied in Lemna gibba. Several laboratories have cloned genes and studied their genetic regulation. To encourage use of duckweeds in teaching I am developing a web site, The Charms of Duckweed, http://www.usra.edu/~jwcross/duckweed.htm. My target viewers are high school and college students and their teachers. Topics include duckweed biology, practical uses and suggestions for experiments and projects. To increase interest, I provide links to "curious facts" and colorful illustrations. Many of the illustrations and links are drawn (with credit) from other sites. This enriches my site and encourages visitors to explore sites with related information. Success of the site may be gauged by the increasing flow of visitors, 352 in the week of 2/21/99. Visitors come from over 32 countries world-wide.