Clonal plants differ from many familiar types of plants and animals, in that they are made up of a number of genetically identical individuals that are interconnected with each other. Increase in population size results from the production of new plants from those that already exist rather than from production of seed. The principal goals of the proposed research are to determine to what degree individual plants that comprise a clone are physiologically linked to each other, what affect the amount of linkage has on the production of new plants, and how the presence or absence of linkage influences the pattern of population growth, and hence, persistence of the clone. Manipulations of resource availability will be performed in the field, and the short-term and long-term developmental consequences of these manipulations studied. Radioactive carbon labeling experiments and tissue nutrient analyses will reveal patterns of resource movement and utilization within clones, and whether they vary through the year. The proposed studies will increase our understanding of the relationship between physiological integration and clonal demography, and contribute to our understanding of the costs of reproduction and the appropriate unit of selection in this and other clonal plants. Many commercially important plants (forage grasses, strawberries), and commercially costly weeds (water hyacinths, crabgrass) grow clonally. Podophyllum peltatum, the subject of this study, is the source of a drug used in cancer treatment, podophyllin, an anti-mitotic agent. Understanding how the environment affects the growth of such plants, and how the degree of physiological integration among the components of such clones may ameliorate these environmental affects, is a critical step in learning how to manage the growth of clonal plants effectively.
