Inheritance of coffee bean sucrose content in the interspecific cross : Coffea pseudozanguebariae x Coffea liberica dewevrei
2001
Ky, Chin-Long | Doulbeau, Sylvie | Guyot, Bernard | Akaffou, S. | Charrier, André | Hamon, Serge | Louarn, Jacques | Noirot, Michel
The sucrose content of coffee beans is an important component of the coffee flavour: the higher the sucrose content in green beans, the more intense coffee cup flavour. Beans of the formerly cultivated Coffea liberica dewevrei (DEW) have lower levels of sucrose (5.37% dmb) than beans of the wild species Coffea pseudozanguebariae (PSE) (7.57% dmb). In the present study, the genetic inheritance of sucrose accumulation in green beans is analysed in an interspecific cross including F1 and backcross hybrids between these two species. Main results concerning genetic inheritance: 1. Between-tree variation exists within species. 2. There is no between-year variation, but an interaction "between-year x tree". 3. Additivity is emphasised for sucrose content in F1 and BCDEW hybrids. 4. Discrepancy to additivity in BCPSE hybrids is due to a segregation distortion eliminating hybrids with sucrose content >5.2% dmb. Conclusions: Our results clearly indicate that, using an interspecific cross with PSE, we can expect an improve-ment of the sucrose content in C. canephora beans. The intraspe-cific variability of C. pseudozangue-bariae and the genetic additivity allow to select genotypes as parent for breeding. As an example, the PSE genotype having 9.25% dmb of sucrose is of special interest. The large within-BCDEW variance, coupled with additivity, strongly suggests that the choice of parents for the next generation BC2 should be efficient. (Résumé d'auteur)
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