Akshay R. Menon

Major: Biology Minor: Religion

University Honors and Honors in Biology

Supervisor: Dr. Ann E. Stapleton

A COMBINATION STRESS OF DROUGHT AND ULTRAVIOLET RADIATION

PRODUCED A LESS THAN ADDITIVE CATALASE ACTIVITY

RESPONSE IN TWO MAIZE GENOTYPES

This study was undertaken to better understand the effect of combination stresses in comparison to individual stresses, specifically the effects of drought and UV, on the maize genotypes Mo17 and B73. Plants of both genotypes were put through treatments of UV drought plus UV, their response to the treatment was measured quantitatively by measuring the activity of the antioxidant enzyme catalase. Variations in catalase responses were analyzed statistically through the use of a factorial ANOVA test. For UV treatment there was a trend toward a more pronounced difference between the treatment and control groups in the MO17 genotype. For the drought treatment there was a trend toward a more pronounced difference between the treatment and control groups in the B73 genotype. However, when exposed to both stresses both the genotypes responded in a similar fashion. This suggests the existence of separate loci for the response to a combined stress treatment.