Global warming is an increasing problem in today’s society. Thus, it is important to know how plants, specifically those that are cultivated for human consumption, react to rising average temperatures. This experiment tested how the leaf size of a common crop plant, Raphanus sativus (radish), is affected by two different temperatures. It is hypothesized that as temperature rises, the leaf size will increase, giving the leaf greater ability to cool via transpiration because of an larger surface area for stomatal conductance. This hypothesis was tested by growing two samples of plants in separate incubators. One sample was grown at a normal atmospheric temperature, and the other at a temperature 6 degrees Celsius higher. The average leaf area of each sample was measured using the Leaf Area Meter. Comparing the average leaf sizes of the group of radishes grown in warmer versus cooler temperatures showed a significant increase in both growth rates and final leaf sizes for the plants grown in the warmer incubator. Therefore, radishes clearly show phenotypic plasticity of their leaf sizes in response to changing temperatures. This morphological adaptation may increase the plant’s physiological fitness in its new environment, giving hope that common crop plants can make some adaptations to the world’s changing climate, mitigating some of the negative effects of global warming for those who rely on such crops for subsistence.
Fleming, Matthew and McCormack, Michael, "Effect of Ambient Air Temperature on Leaf Size in Raphanus sativus" (2012). Pepperdine University, Featured Research. Paper 50.