Avocado Leaf Plasticity
DIFFERENCES IN SUN AND SHADE LEAVES OF AVOCADO TREES BY PHENOTYPIC PLASTICITY
INTRODUCTION: Phenotypic plasticity, or differing phenotypes from one genotype in different environmental conditions, is a way for sessile organisms to adapt to changing environmental conditions (Valladares et al., 2007). Plasticity was expected to be abundant, however, it did not occur as often in nature due to resource limitations and environmental stress (Valladares et al., 2007). An experiment by Matos tested the phenotypic plasticity to light availability in shade and sun leaves of coffee trees (Matos et al., 2009). Their research indicated that "compared [to] sun leaves, shade leaves had a lower stomatal density, a thinner palisade mesophyll, a higher specific leaf area, and improved light capture…" (Matos et al., 2009). The sun leaves were described as "generally thicker with an enhanced quantity of palisade mesophyll" (Matos et al., 2009). Our objective was the presence of phenotypic plasticity in avocado trees based on the differences in the morphology of shade and sun leaves. In our study, we asked whether there is a difference in surface area, length-to-width ratio, mass, specific leaf mass, and color between shade leaves and sun leaves in avocado trees. We hypothesized that there would be no significant differences in surface area, length-to-width ratio, mass, specific leaf mass, and color between shade leaves and sun leaves.
METHODS:
We collected our seventy samples of avocado tree (Persea americana) leaves, in equal amounts of sun and shade leaves, at an avocado tree grove located north of Building 3 and University Drive at Cal Poly Pomona on Thursday, October 24, 2013 at 9:00 am. They were randomly and interspersedly collected throughout the grove. We split the grove into five areas, split into five teams of two, and was assigned to one of the five areas. Each team picked a number for the trees in their region and a random number was selected from a random
INTRODUCTION: Phenotypic plasticity, or differing phenotypes from one genotype in different environmental conditions, is a way for sessile organisms to adapt to changing environmental conditions (Valladares et al., 2007). Plasticity was expected to be abundant, however, it did not occur as often in nature due to resource limitations and environmental stress (Valladares et al., 2007). An experiment by Matos tested the phenotypic plasticity to light availability in shade and sun leaves of coffee trees (Matos et al., 2009). Their research indicated that "compared [to] sun leaves, shade leaves had a lower stomatal density, a thinner palisade mesophyll, a higher specific leaf area, and improved light capture…" (Matos et al., 2009). The sun leaves were described as "generally thicker with an enhanced quantity of palisade mesophyll" (Matos et al., 2009). Our objective was the presence of phenotypic plasticity in avocado trees based on the differences in the morphology of shade and sun leaves. In our study, we asked whether there is a difference in surface area, length-to-width ratio, mass, specific leaf mass, and color between shade leaves and sun leaves in avocado trees. We hypothesized that there would be no significant differences in surface area, length-to-width ratio, mass, specific leaf mass, and color between shade leaves and sun leaves.
METHODS:
We collected our seventy samples of avocado tree (Persea americana) leaves, in equal amounts of sun and shade leaves, at an avocado tree grove located north of Building 3 and University Drive at Cal Poly Pomona on Thursday, October 24, 2013 at 9:00 am. They were randomly and interspersedly collected throughout the grove. We split the grove into five areas, split into five teams of two, and was assigned to one of the five areas. Each team picked a number for the trees in their region and a random number was selected from a random
References: Matos, F.S., R. Wolfgramm, F.V. Goncalves, P.C. Cavatte, M.C. Ventrella, and F.M. DaMatta. 2009. Phenotypic plasticity in response to light in the coffee tree. Environmental and Experimental Botany 67:421-427. Valladares, F., E. Gianoli, and J.M. Gomez. 2007. Ecological limits to plant phenotypic plasticity. New Phytologist 174:749-763.