Effect of different light wavelengths on the overall growth of Arabidopsis thaliana seedlings.

Abstract

This project focused on the effect of different wavelengths of light on the overall growth rate of the Arabidopsis thaliana plant species during their germinating stage. As for any plant species, light is an important factor in the survival and growth of A. thaliana, it must therefore be able to adapt to the varied sources and wavelengths of light available to them in nature. To investigate this, seeds were grown in a controlled laboratory environment under red, green, and blue light, as well as unfiltered lighting (which, in this experiment, was fluorescent lighting with a clear filter), and in darkness, over a span of 11 days. Our alternate hypothesis was that increasing wavelength of light will have a significant positive impact on hypocotyl growth, and the null hypothesis was that increasing wavelengths of light will have no impact or will impede hypocotyl growth. We found that seeds grown in darkness (the positive control treatment) had grown most rapidly. For the coloured treatments, we found that red light had the most growth, followed by the green light, and blue light having the slowest growth rate. The clear plastic treatment was found to have growth similar to the red and green treatments. The results of an ANOVA test done on red, green, and blue light treatments produced a p-value of less than 0.00001, which led us to infer that there is a significant difference in the growth rates of the 3 treatments. This allowed us to reject our null hypothesis and provide support for our alternate hypothesis.