Intraspecific comparisons reveal differences in the pattern of ultraviolet radiation responses in four maize (Zea mays L.) varieties.

Four maize (Zea mays L.) varieties were examined for ultraviolet radiation-induced changes in leaf rolling, biomass, fluctuating leaf asymmetry and DNA damage. Short-term dose-response curves for each response were constructed and responses in each line compared. The four varieties each exhibited a different pattern of tolerance and reactivity, ranging from B73, which was tolerant in all four measures, to TS1, which was affected in DNA damage levels and leaf rolling but unaffected in biomass accumulation and fluctuating leaf asymmetry. The pattern of ultraviolet radiation responses allows us to narrow the possibilities for the source of the defect in reactive varieties. The four varieties tested include inbred parents that have been used to construct recombinant inbred lines and a variety that is found in the background of the engineered RescueMu transposon mutagenesis lines. These dose-response curves and variety comparisons provide the foundation for genetic dissection of the mechanisms of ultraviolet radiation responses in maize.