Biomonitoring plants are used to demonstrate and understand how ozone and other air pollutants affect plant appearance, growth and yield.  Biomonitoring plants developed by the USDA-ARS Plant Science Research group include ozone-sensitive and ozone-resistant clover clones and snap bean lines.  Examples of projects involving snap bean include multi-site ozone-environment modeling studies, physiological studies, and educational activities. 

Effect of ambient ozone on field-grown ozone-sensitive (S156, left) and ozone-resistant (R331, right) snap bean lines.	Ozone injury on sensitive (S156, left) and resistant (R123, right) snap bean plants treated in chambers in the Phytotron.
Ambient ozone injury on an ozone-sensitive (S156) snap bean leaf.	Ozone treatment chambers used in controlled-environment studies.