A genomewide admixture mapping study for yield factors and morphological traits in a cultivated cocoa (Theobroma cacao L.) population
Marcano M., Morales S., Hoyer M.T., Courtois B., Risterucci A.M., Fouet O., Pugh T., Cros E., Gonzalez V., Dagert M., Lanaud C.. 2009. Tree Genetics and Genomes, 5 : p. 329-337.
The selection of productive varieties of modern Criollo cocoa, showing fine aromatic qualities in their beans, is of major interest for some producing countries, such as Venezuela. Cultivated populations of Modern Criollo or Trinitario varieties may be suitable for admixture mapping analysis, as large blocks of alleles derived from two identified divergent ancestors, recently admixed, are still preserved, after a few generations of recombination, similar to experimental mapping progenies. Two hundred and fifty-seven individuals from a cultivated population of Modern Criollo were selected and analysed with 92 microsatellite markers distributed along the genome. This population exhibited a wide range of variability for yield factors and morphological features. Population structure analysis identified two main subgroups corresponding to the admixture from the two ancestors Criollo and Forastero. Several significant associations between markers and phenotypic data (yield factors and morphological traits) were identified by a least squares general linear model (GLM) taking into account the population structure and the percentage of admixture of each individual. Results were compared with classical QTL analyses previously reported for other cacao populations. Most markers associated to quantitative traits were very close to QTLs detected formerly for the same traits. Associations were also identified between markers and several qualitative traits including the red pigmentation observed in different organs, mainly associated to common markers in linkage group 4.
Mots-clés : theobroma cacao; fève de cacao; locus; population végétale; microsatellite; carte génétique; génie génétique; caractère agronomique; locus des caractères quantitatifs; analyse quantitative; analyse qualitative; rendement des cultures; pigmentation; polymorphisme génétique; venezuela (république bolivarienne du); qtl
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Agents Cirad, auteurs de cette publication :
- Fouet Olivier — Bios / UMR AGAP