1996-1997 Research Project

The research project for the 1996/1997 WSSP focused on which wild plant gave rise to domesticated onions, or to put it another way, which species is the Mother-Of-All-Onions?   The goal of this project was to construct a phylogenetic tree of the onion family using DNA sequences generated from the chloroplasts of different onion species.  Students first used a DNA extraction kit to isolate genomic DNA from different onions they found in the store or in the wild.  They then used Polymerase Chain Reaction (PCR) to amplify a specific fragment of the onion chloroplast genome, cloned the fragment into a plasmid vector, and then transformed bacteria.  Students then purified the plasmid DNA and the region containing the onion gene fragment was sequenced.  These sequences were used to search for matches in the NCBI database using the BLASTN program and the information from these analyses allowed students to determine the location of their sample on the onion phylogenetic tree.  In the course of these studies, students, teachers, and research scientists worked together, using the basic principles of molecular biology and genetic engineering to try to solve this research problem. By actually doing science, teachers and students gained an understanding of how science operates.