Submitted to: California Separation Science Society
Publication Type: Abstract Only
Publication Acceptance Date: August 1, 2002
Publication Date: August 18, 2002
Citation: Saunders, J.A., Loor, R., Mischke, B.S. 2002. The use of capillary electrophoresis for dna fingerprinting in cacao [abstract]. California Separation Science Society.
DNA fingerprinting, a tool that has been widely used in forensic science, is also useful in plants to identify specific types of genotypes for breeding populations. We have applied Simple Sequence Repeat (SSR) DNA analysis to samples of Theobroma cacao grown in several tropical locations including Puerto Rico, Costa Rica, Ecuador and Trinidad and Tobago. This technique utilizes PCR amplification to produce multiple DNA fragments, which are separated with a one base pair resolution by multichannel capillary electrophoresis. We have analyzed supposedly identical samples held in germplasm collections in the various countries and found that a significant number of errors exist in the identification of cacao trees. Elite populations of high quality cacao found in Ecuador were also analyzed using 15 different SSR primer pairs to investigate the genetic diversity of these samples. When these Ecuadorian Ariba type cacao trees were analyzed in this manner they demonstrated the limited genetic diversity of this collection compared with the cacao samples taken at random from other sources. The utility of the capillary electrophoresis separation systems allows for high throughput DNA fingerprinting of these samples for essential identity studies. This technique can now be used in a routine manner to assess the genetic diversity of T. cacao collections from world populations.