The ozone-sensitive and ozone-tolerant snap bean (Phaseolus vulgaris L.) lines were originally derived from a cross between Wade Bush (ozone-tolerant) and Oregon 91 (ozone-sensitive) (Reinert and Eason 2000).  Progeny were screened in ambient-air field studies and ozone sensitivity was found to be a dominant genetic trait.  Screening of selfed generations allowed selections of extremes in ozone sensitivity (KO Burkey, pers. comm.).

Sensitive line - S156;  Resistant lines - R123, R331

Ozone-sensitive (S156) and ozone-tolerant (R123) snap beans
following exposure to ambient ozone in Phytotron chambers for 20 days.

Reinert, RA and G Eason. 2000. Genetic control of ozone sensitivity in a cross between two cultivars of snap bean.  J. Am. Soc. Hort. Sci. 125:222-227.