Deciphering the nearest living relatives of non-chlorophytic parasitic plants has been difficult; scientists looking at plant relationships often use changes within the DNA of the chloroplasts to determine how plants are related. Researchers at Western Michigan University, Universiti Kebangsaan Malaysia and Sabah Parks (Malaysia) instead looked at mitochondrial DNA (mtDNA), which is not often used, and were able to determine that Rafflesia (the plant with the largest flower) and Mitrastema are not closely related. This suggests that parasitism has evolved multiple times in different lineages of plants.
World's Largest Flower Mystery Solved from the Discovery Channel, which concentrates on the story behind determining the relatives of Rafflesia and concludes on the depressing suggestion that the largest known flowers may soon become extinct.
Mitochondrial DNA sequences reveal the photosynthetic relatives of Rafflesia, the world's largest flower - link to the Proceedings of the National Academy of Sciences journal abstract (Barkman et al., 2004, Proc. Nat. Acad. Sci. 101:3, 787-792). Those with subscriptions can read the full article online as well.
Posted by Daniel Mosquin at 05:20 PM on January 20, 2004