Effects of Shade on Holy Basil (Ocimum sanctum).


Search abstracts:

Landon Dillingham
Committee: Steve Cartier, Alisa Hove, Jeff Holmes

In this study, I investigated the role of photosynthesis in eugenol production in Holy basil (Ocimum sanctum). Objectives included cultivating forty plants, 20 in full sun (control) and 20 in shade (treatment), then quantifying and comparing the photosynthetic efficiency and eugenol content of each plant. Methods included using the LI-COR 6000 to measure gas exchange in a leaf of each individual, and HPLC was used to measure constituent concentration of each individual. A Wilcoxon rank sum analysis was used to compare the data from the treatment groups. The full sun (control) group had increased photosynthetic efficiency compared to the shade (treatment) group with a p<.001. HPLC analysis results were inconclusive regarding shade plants as concentrations were too low to detect. The analysis succeeded in measuring eugenol concentration of all the full sun (control) group, the average concentration was 28 ppm by dry mass. Additionally, the full sun (control) group’s photosynthetic data and eugenol concentration were compared using a linear regression test with no correlation found R 2 = .087 and p>.005. Results show that Ocimum sanctum has greater photosynthetic efficiency in full sun compared to plants grown in 80% shade. The comparison of photosynthesis to constituent production showed no correlation.