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United States Department of Agriculture

Agricultural Research Service

Research Project: Genetic Improvement of Cacao Through Genomics-Assisted Breeding

Location: Subtropical Horticulture Research

Title: Toward the identification of candidate genes involved In black pod disease resistance in Theobroma cacao L.

Authors
item Livingstone Iii, Donald -
item Gutierrez, Osman
item Royaert, Stefan -
item Epaina, Peter -
item Kuhn, David
item Schnell, Raymond -
item Motamayor, Juan Carlos -

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 1, 2013
Publication Date: January 11, 2013
Citation: Livingstone Iii, D., Gutierrez, O.A., Royaert, S., Epaina, P., Kuhn, D.N., Schnell, R.J., Motamayor, J. 2013. Toward the identification of candidate genes involved In black pod disease resistance in Theobroma cacao L.. Meeting Abstract. Int'l Plant & Animal Genome XXI Conference, San Diego, CA, January 12-16, 2013.

Technical Abstract: Black Pod (Phytophthora sp.) has a devastating effect on the worldwide cacao (Theobroma cacao) yield and incorporating resistance into production fields has been an ongoing effort of breeding programs. Previous meta-QTL analysis of genetic maps created with a variety of molecular markers identified 13 consensus QTLs. The resolution of these QTLs suffered from being associated with genetic maps with limited numbers of molecular markers. Recently, three mapping populations were genotyped with a total of 6000 SNP markers. Reciprocal crosses were made from ‘K82’ (resistant) and ‘KA2-101’ (susceptible), the resulting progeny were found to segregate for Black Pod resistance, and saturated genetic SNP maps were generated. The forward cross ('K82' x 'KA2-101') consists of 215 individual trees and 2545 SNP markers, while the reverse cross ('KA2-101' x 'K82') has 110 individual trees and 2546 SNP markers. Field-based pod rot phenotype data was collected on these populations over two years. QTL analysis for Black Pod resistance is performed and compared to previously identified consensus QTLs. Furthermore, candidate genes within identified QTLs will be investigated, and an association between resistance and parental haplotypes will be explored. The identification of QTLs with a saturated genetic map, and the identification of genes potentially involved in Black Pod resistance will help breeding programs and may ultimately reduce global cacao losses.

Last Modified: 8/21/2014
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