On coffee (Dossier)
Avancées et perspectives de la recherche internationale sur le café (Cahiers Agricultures)
18/09/2013 - Article
Researchers from CIRAD and its partner, Ecom Agroindustrial, have just mastered a cutting edge propagation technique, cell suspension, for Coffea arabica. This key stage in the propagation of in vitro plantlets through somatic embryogenesis will make it possible to produce the millions of coffee plantlets required to meet market demand for high-quality selected varieties. This pioneering work opens up new possibilities for the propagation of plants and varieties on an industrial scale. It will also mean considerably higher income levels for many producers.
Being robust, resistant to disease, productive and bred from the best stock, the Coffea arabica F1 hybrids developed by CIRAD over the last 20 years have proven their effectiveness and are now in high demand among planters.
These hybrids increase production by 50 to 60% and are also a way to ensure the profitability of agroforestry systems, which planters have gradually abandoned due to the low productivity of traditional shade-grown varieties.
It therefore goes without saying that the industrial production of hybrid plantlets is eagerly awaited. The propagation of plantlets through somatic embryogenesis* is currently the most effective and rapid means of achieving this objective. Yet output does not meet producers’ requirements: 30 to 50 million plantlets are needed on the market every year in Central America, as well as in the other coffee-growing regions. The only solution is cell suspension, a promising technique for rapid cell propagation in liquid medium. But until now, the process was poorly understood for most plant species, and propagators’ attempts have ended in failure. However, researchers from CIRAD, in partnership with the Ecom Agroindustrial group, have recently risen to the challenge with the development of a new protocol, which has been tested with great success.
The technique is now fully mastered, thereby avoiding the risk of somaclonal variations, which were previously common in Arabica coffee plantlets produced from cell suspensions. It was tested on 800 000 in vitro plantlets, which were observed individually in the nursery or in the field. The results are unequivocal: more than 99% of the regenerated coffee plantlets are strictly true-to-type in relation to the mother plant, in terms of genetics, epigenetics and morphology – they grow, flower and yield normally.
This result paves the way for using this technique with other plants: a revolution in the world of plant micropropagation at the industrial scale. It is also a revolution for the main beneficiaries of these varieties: the coffee producers who, according to a recent impact analysis, will benefit from a gain of around 6 000 USD/ha five years after planting the hybrids as opposed to growing the best conventional varieties.
* Somatic embryogenesis is an in vitro culture technique that makes it possible to regenerate large quantities of true-to-type plants (clonal reproduction) using just a fragment of the mother plant.