Cocoa : breeding strategies.
Genetic improvement of cocoa (Theobroma cacao) began with the domestication of Criollo varieties in Central America. They were gradually superseded by Trinitario selections, then by Forastero trees, which have better disease and insect resistance. In 1940, crossing Forastero lines, collected during survey in Upper Amazonia, with other genetic groups resulted in substantial increases in precocity and productivity. Hybrids between different genetic groups were distributed widely. Since the 1980's, there has been a move towards hybridizing doubled haploids, choosing parents based on genetic characters, recurrent selection and index selection of individuals amongst the best progenies. Molecular markers (RFLP and RAPD) have provided a clearer picture of genetic diversity and has enabled genome mapping. Resistance to diseases and insects and improved quality remain major breeding objectives. More efficient evaluation of germplasm, recurrent selection, markerassisted selection and micropropagation may contribute to solving these problems.
| Main Authors: | , |
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| Format: | Texto biblioteca |
| Language: | - F |
| Subjects: | beverage crops, breeding, Coco., genetic diversity, genetic markers, plant breeding, random amplified polymorphic DNA, recurrent selection, restriction fragment length polymorphism, stimulant plants, Breeding, Genetic markers, Plant breeding, |
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