Skip to main content
ARS Home » Research » Publications at this Location » Publication #124543


item Saunders, James
item Mischke, Barbara

Submitted to: DNA Sequence
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2002
Publication Date: N/A
Citation: N/A

Interpretive Summary: Living germplasm collections of Theobroma cacao, the chocolate tree, 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 molecular tools for DNA fingerprinting techniques, in order to utilize these collections effectively. AFLP DNA analysis techniques were performed on T. cacao germplasm to evaluate the utility of this procedure for DNA fingerprinting of the tree crop. Using these procedures, DNA fragment patterns were consistent within a common varietal genotype, while differentiating separate genotypes. Based on this study, individual plants can be obtained and screened for disease resistance to identify plants that can survive disease pressure in South America. These chocolate plants can then be used as an alternative cash crop for opium poppy and coca in narcotic producing countries.

Technical Abstract: DNA fingerprinting, a tool which has been widely used in forensic science, is also useful in a variety of applications with plants. It is used to identify genetic diversity within breeding populations, to positively identify and differentiate accessions, cultivars, and species that might be difficult to characterize due to similar morphological characteristics or indistinct traits, and to identify plants containing genes of interest such as the confirmation of transformation events. A number of molecular tools and procedures are being employed to establish DNA fingerprinting profiles and each of these procedures have its strengths and weaknesses. Amplified restriction Fragment Length Polymorphic (AFLP) DNA analysis, is a useful procedure for DNA fingerprinting, especially when very little information is known about the genome of the plant under study. AFLP DNA analysis of plants is also a useful procedure for quickly assessing the genetic background of selected lines or populations of cacao.