Genetic Relationships within Tripsacum as Detected by RAPD Variation

Genetic diversity within species of Tripsacum was surveyed basedon randomly amplified polymorphic DNA (RAPD) variation, as detectedwith the polymerase chain reaction (PCR). Thirteen of the 16Tripsacum species, including both temperate and tropical species,were included in this study using 56 decamer oligonucleotideprimers. All of the 56 primers generated repeatable RAPD profilesand 53 of them detected polymorphic bands among the Tripsacumspecies. These 53 primers generated 350 repeatable bands rangingin size from 150–1600 bp, each primer generating an averageof seven scoreable bands. Cluster analysis of polymorphic RAPDsindicated four major clusters. Cluster 1 consists of North AmericanTripsacum species, cluster 2 consists of South American Tripsacumspecies, cluster 3 includes T. zopilotense and T. latifoliumfrom Mexico, and cluster 4 consists of Mesoamerican Tripsacumspecies. Cluster analysis does not reveal the division of twotaxonomic sections (Fasciculata and Tripsacum). Copyright 1999Annals of Botany Company Tripsacum, RAPD, genetic relationships, genetic diversity.