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Bouncing bet growth patterns

J’Nai Macklin and Khadijah Crosby
Independent research, BIO 490, Biology Department, DePauw University
Spring semester 2016

The goal of our study was to compare leaf size of eight clonal genotypes of Saponaria officinalis in the sun vs. shade.  We were interested in assessing the extent of genetic variation and phenotypic plasticity of the plants. 

There were 30 clones of 8 genotypes of plants grown in an experimental garden outside the Manning Environmental Field Station in the DePauw Nature Park.  The garden included 5 sun plots and 5 shade plots.  We collected 24 leaves from each plot.  We weighed the leaves and measured their area using a leaf area meter.  We calculated specific leaf area (leaf area divided by dry mass) and leaf dry matter content (saturated mass divided by dry mass). 

Results and Discussion
Leaves in the sun were thicker and weighed more whereas leaves in the shade covered a larger surface area.  We found significant differences among the genotypes; genotype B tended to have smaller leaves than genotype D in both the sun and shade.   Our results indicate that the plants showed genetic variation and phenotypic plasticity in response to sun and shade.