MRI: Development of a Phytotron Facility for Vassar College Biological and Environmental Sciences

Vassar College, Poughkeepsie NY

Investigators

Abstract

A grant has been awarded to Dr. A. Marshall Pregnall at Vassar College develop a phytotron facility in the Biology Department in order to enhance faculty research and student research training in biology and environmental science. By acquiring seven new controlled environment chambers, the Biology Department will increase its growth chamber capacity from five to 12, which will expand the number of concurrent research projects and improve treatment replication for controlled-environment experiments on seagrass and algal physiological ecology, plant-mycorrhizal interactions, and plant reproductive ecology. Moreover, the Biology Department will be able to maintain long-term selection lines for student research on quantitative genetics, better control conditions for student experiments in plant physiology, and enhance research training for upperclassmen in biological and environmental sciences. Dr. Pregnall will utilize the phytotron facility in several research projects. Growth chambers will be used to determine seasonal and environmental cues that regulate inorganic nitrogen assimilation by the seagrass Zostera marina. Dr. Pregnall will create a matrix of photoperiod-times- temperature-times- nitrate enrichment treatments to isolate the discrete and interactive effects of winter vs. summer conditions of light and temperature along with variable nitrogen availability. Dr. Pregnall will also measure the tolerance and physiological responses of coastal macroalgae to pulsed episodes of hypoxia and anoxia by manipulating temperature, aeration and the presence of sediments. Additionally, he will assess the contribution of water-column and sediment microbial nitrification to the inorganic nitrogen cycling in a watershed. Dr. Margaret Ronsheim will use the phytotron in her studies of the interactions between plant genotype, mycorrhizal associations, and soil pathogens on reproductive allocation and success in Allium vineale. Dr. Mark Schlessman will perform experimental tests of hypotheses relating optimal plant size and flowering time using rapid-cycling Brassica rapa. Additionally, undergraduate students will utilize the phytotron facility for research projects in 200- and 300-level courses in Biology and Environmental Science, for independent honors projects and during summer research internships with individual faculty. In each of these studies, students would work with experimental designs and statistical analyses utilizing split-plot, factorial, repeated measures ANOVA, thus gaining important experience with assessing primary and interaction effects and dependence of time responses on initial conditions. The development of the phytotron facility at Vassar College will greatly expand faculty and student research in physiological ecology, plant reproductive ecology and environmental sciences by permitting statistically powerful experimental designs while simultaneously supporting long-term manipulations and organism growth in controlled conditions. Precise control of temperature, humidity, daylength, and light intensity in multiple growth chambers will allow experiments to consider more than one factor and their possible interactions as the organisms respond through time to the different treatments. Since organism and ecosystem responses are usually sensitive to multiple factors, use of the phytotron by faculty and students will allow more complex, realistic experiments with sufficient replication to achieve valid testing of hypotheses.