Systematics Section / ASPT
Crawford, Daniel J. , Mort, Mark E. , Santos-Guerra, Arnoldo .
Allozyme Diversity in Tolpis laciniata (Asteraceae: Lactuceae), a Species Endemic to the Canary Islands.
Tolpis laciniata is endemic to the Canary Islands, where it occurs on four of the seven islands. The species is morphologically variable, especially in leaf dissection and pubescence, and in the capitulescence. The species is diploid (2n=18), and occupies a variety of habitatsranging from rocks at sea level to humid forests in the high mountains. . Enzyme electrophoresis was used to assess genetic diversity at18 loci within and among 17 populations from the islands of El Hierro, La Gomera, and La Palma. The level of allozyme diversity in T. laciniata is much higher than the average for most species endemic to oceanic islands, with over half of the loci polymorphic at the species level. Diversity in populations from La Palma is about fifty percent higher than for populations on La Gomera and nearly three times greater than populations sampled from El Hierro. Alleles found in populations in El Hierro and La Gomera represent almost exclusively a subset of the alleles detected in plants from La Palma, suggesting that the center of diversity for the species is La Palma, with possible dispersal to the other two nearby islands. The level and apportionment of diversity will be discussed in the context of the ages of the islands, the volcanic history of the islands, distances between islands, and possible agents for dispersal of fruits among the islands.
1 - Jardin de Aclimatacion de la Orotava, Calle Retama Numero 2, Puerto de la Cruz, Teneri, Canary Islands, E-38040, Spain
2 - University of Kansas, Dept. Ecol. & Evol. Biol. and Natural History Museum, 1200 Sunnyside Ave., Lawrence, Kansas, 66045-7534, USA
Presentation Type: Poster
Location: Special Event Center (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 12:30 PM