ARS | Publication request: Development of a high throughput SNP assay for marker-assisted breeding of Theobroma cacao in cacao producing countries

Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: September 29, 2006
Publication Date: January 13, 2007
Citation: Kuhn, D.N., Motamayor, J.C., Schnell Ii, R.J. Development of a high throughput SNP assay for marker-assisted breeding of Theobroma cacao in cacao producing countries. Plant and Animal Genome VX Conference Abstracts.

Technical Abstract: Two commercially important diseases of Theobroma cacao are witches' broom (Moniliophthora perniciosa) and frosty pod (Moniliophthora roreri). Dr. Raymond Schnell is coordinating a major international breeding program for disease resistance in cacao in countries such as Ecuador and Ghana where laboratories capable of high-throughput molecular genotyping are not available for plant breeding applications. We have identified quantitative trait loci (QTL) for witches' broom resistance (two QTL) and frosty pod resistance (three QTL). In the current breeding programs, parents are often heterozygous at a QTL so that only one quarter of the F1 population will contain the allele associated with resistance. Breeding three crops is expensive and requires significant time and space. We would like to use our molecular genetic markers to remove at the seedling state the progeny that lack the alleles associated with the desirable QTL. We are developing a molecular genetic assay based on single nucleotide polymorphisms (SNPs) that can be easily and accurately accomplished in producer countries and does not require refrigeration for storage of either DNA or reagents, does not require full time lab personnel or a specialized lab area, does not require uninterrupted electric supply, does not require shipment or storage of labile molecular biology reagents and can be performed and analyzed by current personnel in the producer countries without specialized training or prior familiarity with molecular biology techniques.