Kalindi LaTorre

Honors in Biology

Major: Biology

Supervisor: Ann Stapleton, Biology and Marine Biology

Multiple Stress Dose Response Comparison of Two Genotypes

Combinations of stress factors normally occur in the field, and both crop stress and general environmental ecological data suggest that combination stress effects are not easy to predict from single stress experimental analyses. Stress-combination differences may also explain why correlation of specific climate variables with QTL across environments has been difficult. In this study, the difference in compounded UV/drought stress response between B73 and MO77 maize genotypes was tested. The two genotypes, B73 and the IBM RI line MO77, were divided into test groups: a control group, groups with varying levels of compounded UV and drought, a group with UV but not drought, and a group with drought but no UV. Stress was applied to the plants in a week long trial, and then differences in plant height before and after stress treatments were measured. Total shoot mass and total root biomass were also measured after the stress treatments. An ANOVA test was conducted on the three experimental variables. Response surfaces were fit in order to compare the stress reaction of the two genotypes to one another. This comparison will allow us to select a suitable drought and UV combination dose for QTL mapping.