Genetic relationships within Tripsacum as detected by RAPD variation

Abstract

Genetic diversity within species of Tripsacum was surveyed based on randomly amplified polymorphic DNA (RAPD) variation, as detected with the polymerase chain reaction (PCR). Thirteen of the 16 Tripsacum species, including both temperate and tropical species, were included in this study using 56 decamer oligonucleotide primers. All of the 56 primers generated repeatable RAPD profiles and 53 of them detected polymorphic bands among the Tripsacum species. These 53 primers generated 350 repeatable bands ranging in size from 150-1600 bp, each primer generating an average of seven scoreable bands. Cluster analysis of polymorphic RAPDs indicated four major clusters. Cluster 1 consists of North American Tripsacum species, cluster 2 consists of South American Tripsacum species, cluster 3 includes T. zopilotense and T. latifolium from Mexico, and cluster 4 consists of Mesoamerican Tripsacum species. Cluster analysis does not reveal the division of two taxonomic sections (Fasciculata and Tripsacum).