Submitted to: Genetic Analysis Techniques and Applications
Publication Type: Proceedings
Publication Acceptance Date: 5/7/2001
Publication Date: 5/15/2001
Citation: Saunders, J.A., Mischke, B.S. 2001. Dna fingerprinting of chocolate and other crops. Genetic Analysis Techniques and Applications.
Technical Abstract: Living germplasm collections of Theobroma cacao genotypes are maintained in several international collections scattered throughout Central and South America and Caribbean Islands. The United States Department of Agriculture has begun a program to identify and describe the genetic diversity of these collections using state of the art molecular fingerprinting techniques. Two separate molecular analysis techniques, AFLP DNA analyses and SSR DNA analysis were performed on T. cacao germplasm to evaluate the utility of these procedures for DNA fingerprinting of this tree crop. DNA fragments were selectively amplified, labeled with fluorescent dyes and separated by capillary electrophoresis using two different models of DNA analyzers (an ABI/Perkin Elmer 310 single capillary injector and a Beckman CEQ 2000 eight channel capillary DNA analyzer). Using either procedure, electopherograms of DNA fragment patterns were reproducible and consistent within a common genotype, while differentiating separate genotypes. Similarity dendrograms were based on the combined cluster analysis of AFLP primer sets of polymorphic peaks or from SSR primers selectively amplified with PCR technology. Based on this study, 15 primers for SSR markers have been selected as an international standard technique for T. cacao molecular characterization.