A team from CIRAD has developed the first Arabica F1 hybrid produced from seed that is suitable for cost-effective production on a large scale.
The seeds of the variety, Starmaya, cost half as much to produce as F1 hybrid in vitro plantlets that are currently available. “This is a minor revolution for the coffee industry,” said CIRAD.
Arabica is self-fertilizing, which hampers the creation of hybrid varieties in the field. In the field, propagation by pollination produces mainly seeds from a single variety, a single parent (known as a line).
Cross-fertilization between two distinct individuals is still possible, however, and Arabica F1 hybrids can be produced by crossing two varieties. However, producing F1 hybrid seeds means hand pollination, dusting pollen from one parent onto the flowers of the other.
When millions of hybrid seeds are required, hand pollination is no longer viable, since each flower must be modified by hand before being dusted with pollen from the other parent.
To date, F1 hybrids have been produced by cloning, in an in vitro culture laboratory (by somatic embryogenesis) or in nurseries, using horticultural propagation techniques.
“Micropropagation methods are efficient but very costly, which has prevented many coffee producers from adopting this type of improved material,” said Frédéric Georget, a biotechnologist with CIRAD in Costa Rica. “However, this technical obstacle has now been overcome in Nicaragua, thanks to a new variety, Starmaya, created by CIRAD and Ecom Agroindustrial Corp.”
Starmaya is the progeny of two parents, Marsellesa and CIR-SM01. The Marsellesa line (created by CIRAD) was chosen for its resistance to coffee leaf rust and its organoleptic qualities. Starmaya’s novelty lies in the use of CIR-SM01: researchers discovered that it does not produce pollen – in other words it is male-sterile.
Planting the two parent varieties side by side in a seed garden ensures that the only pollen produced by Marsellesa will fertilize the CIR-SM01 plants. The seeds produced by CIR-SM01 as a result of this natural cross-pollination are therefore all F1 hybrids of the new Starmaya variety.
Using this simple mechanism of cross-pollination between a male pollen donor parent and a ‘male-sterile’ parent means that mass production of commercial Starmaya seeds is now possible, and that those seeds are half the price of the Arabica F1 hybrid in vitro plantlets current available.
“The production potential for the Starmaya variety is around half a million seeds per hectare planted,” said Benoît Bertrand, creator of the variety and CIRAD Coffee Value Chain Correspondent.
In addition to being easy to produce, Starmaya has all the expected advantages of a commercial hybrid variety. It is high yielding, robust, and has excellent organoleptic qualities.
The only snag is that 10% of plants will not be true to type. “This is mainly because the male-sterile CIR-MS01 cultivar is not sufficiently genetically fixed to produce an entirely uniform F1 population,” Mr Bertrand explained. “Nevertheless, Starmaya is a huge step forward in terms of productivity (+ 20 to + 40%) and quality, compared to the commercial Arabica varieties currently on the market.”
Sustainable Management Service, a seed production subsidiary of Ecom Agroindustrial in Nicaragua is planning to market the seeds.