Evolutionary relationships among parasitic flowering plants are very poorly known because of frequent morphological reductions in floral and vegetative features. The group of parasitic plants that will be examined in this project by Dr. Daniel Nickrent of University of Illinois is called the Santalales, an order that includes sandalwood, the familiar Christmas mistletoe, and several less familiar aerial and root parasites. Evolutionary relationships within representatives of several families in the order will be determined by comparison of DNA sequences that code for ribosomal RNA (rDNA). This will be accomplished by using a new technique called PCR which allows for amplification of the amount of DNA in a sample, thus providing a high enough concentration for sequencing. Generation of rDNA sequences is rapid and efficient and provides a large number of characters (nucleotide bases) useful in determining relationships. In addition to representatives of the five families in the Santalales, sequences of other plants doubtfully included in this order will be determined to ascertain their correct taxonomic placement. This second group of parasites includes the enigmatic and spectacular Rafflesia which has the largest flower among all flowering plants, as well as some tiny-flowered parasites originally (and incorrectly) classified with the fungi. Representatives from other orders thought to be related to these parasites will also be sequenced thus providing information relating to the origin of parasitism in the flowering plants.
