title: Resistance gene homologues in Theobroma cacao as useful genetic markers.
abstract: Resistance gene homologue (RGH) sequences have been developed into useful genetic markers for marker-assisted selection (MAS) of disease resistant Theobroma cacao. A plasmid library of amplified fragments was created from seven different cultivars of cacao. Over 600 cloned recombinant amplicons were evaluated. From these, 74 unique RGHs were identified that could be placed into 11 categories based on sequence analysis. Primers specific to each category were designed. The primers specific for a single RGH category amplified fragments of equal length from the seven different cultivars used to create the library. However, these fragments exhibited single-strand conformational polymorphism (SSCP), which allowed us to map six of the RGH categories in an F(2) population of T. cacao. RGHs 1, 4 and 5 were in the same linkage group, with RGH 4 and 5 separated by less than 4 cM. As SSCP can be efficiently performed on our automated sequencer, we have developed a convenient and rapid high throughput assay for RGH alleles.
authors.affiliation: Department of Biological Sciences, Florida International University, University Park, Miami, FL 33199, USA.
authors.forename: D N
authors.initials: DN
authors.lastname: Kuhn
authors.forename: M
authors.initials: M
authors.lastname: Heath
authors.forename: R J
authors.initials: RJ
authors.lastname: Wisser
authors.forename: A
authors.initials: A
authors.lastname: Meerow
authors.forename: J S
authors.initials: JS
authors.lastname: Brown
authors.forename: U
authors.initials: U
authors.lastname: Lopes
authors.forename: R J
authors.initials: RJ
authors.lastname: Schnell
mesh_terms: D000595:Amino Acid Sequence; D002099:Cacao / Q000235:genetics*; D002874:Chromosome Mapping; D016000:Cluster Analysis; D017931:DNA Primers; D018742:DNA, Chloroplast / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics*; D007113:Immunity, Innate / Q000235:genetics*; D018895:Microsatellite Repeats; D008969:Molecular Sequence Data; D010802:Phylogeny; D018807:Polymorphism, Single-Stranded Conformational; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D018742:DNA, Chloroplast; D005819:Genetic Markers