What is somatic cell cloning?
What is a clone?
Cloning is basically taking a cutting (a branch or growing portion of the plant, including a few small leaves to aid growth) of one plant, and placing it in a medium to take root on its own. This cutting then becomes its own plant, identical to the “parent” plant (the plant from which the clone was taken). Cloning has become one of the most efficient ways to grow a plant. Clones are the result of asexual or vegetative propagation, whereas seeds are the result of sexual propagation.
What is somatic cell embryogenesis and why is it important to the future of Cacao?
In just the same way a cutting can sprout roots, other portions of a plant can grow to form new plants as well. In somatic cloning of cacao we grow plants from a portion of a non pollinated flower.
Cacao Prieto and Cacao Biotechnologies are pioneering the use of somatic cell cloning or embryogenesis to preserve biodiversity and improve cacao production of the Dominican Republic.
The Dominican Republic is one of the smallest producers of Cacao in the world producing only 1.4% of the world supply, but the Dominican Republic is also one of the most important producers as that 1.4% equals 70% of the worlds supply of Organic cacao produced each year.
Below is an example of an excellent cacao tree, in fact this is a farmer’s dream tree:
It is a fine flavor, high productivity tree, which as you can see is surrounded by low yielding trees.
In a typical farm only 5% of trees could be considered excellent. These excellent trees account for more than 50% of the farms production.
So many of the problems the world Cacao industry faces are economic in origin. Organic production is practiced in the Dominican Republic because it is cultural. The bottom line is that organic cultivation of cacao make little financial sense. Yields of typical organic plantations are much less than 1/2 that of chemically fertilized farms, and the premium received for growing organic is only 10% more. Farmers can make almost double the money NOT growing organic, and even more growing low flavor quality high yielding hybrids.
Cacao Prieto is changing this dynamic by implementing high tech propagation and farming techniques.
By identifying excellent trees and propagating from 5% of the farm to 100% of the farm, changing nothing else we can increase the production 500%. Augment this with new pruning techniques, high density planting, centralized composting and biochar and we are making sustainable and organic cacao agriculture viable. Mono-cultures are not applied but rather mixed fields of dozens of “excellent” genetic hybrids are used.
We started by extensively surveying thousands of hectares of cacao land in the Dominican Republic, painstakingly collecting samples and tagging trees.
Trees of interest were extensively tested using dna, metalbolomics, proteomics and mass spectrometry/gas chromatography tests to identify high value traits. Examples of high value traits range from disease resistance, to superior organoleptic properties, to increased quantities of healthy compounds for food or pharmaceutical use.
Once a valuable trait is identified in a hybrid, we take steps to protect and multiply a genetic collection. Cacao is unique in that seeds can not be saved. If dried or frozen the seeds become non viable and die. Cacao biodiversity must be preserved by propagating living collections. When a valuable plant is discovered it is typically the only one that exists in the world. If you plant the seeds from a unique plant, you will be getting different genetics in the seedling. The desirable trait you are hoping for is possibly lost (as seeds are produced by mating random 50% Genetic material from father & mother in a shuffle and passed into the offspring). To multiply a single tree into a safe population, cuttings were previously the only method. There is a limit to how many cuttings can be taken from a mother tree (especially old trees) which hence limits the ability to get a new hybrid established in commercially viable amounts in an acceptable time. For example if we wanted to replant our farm with an excellent hybrid we discovered, using only cuttings would literately take an entire life time to accomplish.
Cacao Prieto is pioneering the use of somatic cell embrogenis, a non-GMO technique which allows us to collect the unopened flowers of a rare plant,
dissect in a sterile environment,
The embryos are grown out in additional petri dishes into plantlets just the same if they had come from seed.
The process of moving from petri dish to petri dish does require a certain amount of labor and to further increase efficiency we are developing bio-reactors that allow larger numbers of embryos/plantlets to be grown at one time.
From each flower we can produce 8000 embryos, each of which will develop into plantlets just the same as a germinating seed. Every embryo will have an identical genetic structure to the mother flower. They are clones in just the same way a rooted cutting is a clone of the parent tree. In this way we have developed a method, a “pipeline” where we can create 8000 plants from one, which are then planted in a field spaced 1 meter apart as a high density- “germplasm repository”. In one year these plants are large enough to multiply further by harvesting cuttings, which are then rooted to place into production fields. From this step we can create approximately 80+ every 6 weeks from each of the 8000 trees.
In this electron micrograph picture you can see the a staminode from a cacao flower on a sugar agar petri dish:
In several days cells begin to grow:
Soon embryos will form:
When our plants get too big for the petri dishes we move to small containers:
When they get a little larger they are moved to the green house for acclimatization before going into the field.
Cacao is entering truly exciting times !