Re: "Living geiger counters"

[GACarlson@aol.com]

A few excerpts from the results of a Hotbot search for "spiderwort" and 
"radiation."

"Another interesting plant to observe notable phenotypic changes in is the 
spiderwort, Tradescantia.  Carolina has written a nice Carolina Facts handout 
on this.  The cells of the anther turn colors with exposure to radiation.  It 
can be seen under the light microscope,
counted and quantitated.  Years ago I had a student do a science fair poject 
on this.  If I remember correctly, they turned from blue to pink. She exposed 
the plants to Xray at a vet's office."  
http://sun.simmons.edu/archives/plants/msg00005.html

"The influence of microgravity on the effects of low-LET radiation has been 
reviewed by Horneck (60) and was discussed by Nelson (61).  Most experiments 
showed negligible or small effects of microgravity on radiation-induced 
changes. Typical changes observed had to do with increased chromosomal 
alterations in fruit flies and in Tradescantia (the spiderwort plant) 
following irradiation before liftoff. Horneck suggests that changes in 
chromosomal structure or position in microgravity could have prevented 
effective rejoining of chromosomes."  http://www.nas.edu/ssb/csbmch11.htm

"Spiderwort: Nature's Geiger Counter. 'Well-Being,' No. 50, December 1979."  
http://www.stevenfoster.com/text/publications/consumer.html

"Unusual features of Spiderwort flowers are the bow-tie shaped anthers and 
the furry filaments. The flowers can be of different colors, depending on 
soil pH and other environmental factors. The cells of the filament hairs 
mutate easily and the plants have been grown near nuclear plants as a 
biological radiation detector." http://csdl.tamu.edu/FLORA/LCP/LCP2B.HTML

Glenn
GACarlson@aol.com

In a message dated 04/07/99 10:33:17 AM Central Daylight Time, 
GACarlson@aol.com writes:

> Subj:	 "Living geiger counters"
>  
>  On page 391 of the March 1983 issue of National Geographic magazine is a 
>  photograph of a flower apparently identified as Tradescantia virginiana .  
>  Below the photograph is the caption:
>  
>  "Living geiger counters, the stamen hairs of spiderworts change from blue 
to 
>  pink when exposed to radiation and air pollutants."
************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html