4. Plant Improvement

Pollination: 

The cocoa plant is self-compatible and self-incompatible at the same time. That means it can perform both self-pollination and cross-pollination.
Self-pollination means that a plant has the ability to fertilize itsself. These plants have complete flowers including stamen and pistils. This can happen within the same flower or between two flowers on the same plant whereas cross-pollination requires two individual plants. The pollen from one plant fertilizes the ovule on the second plant.
The genotype of Theobroma Cacao is diploid (2n=20).

Figure 1

Plant Breeding and Plant Improvement:  

Grafting:
Grafting is one method how cocoa plants are propagated. Grafting is the process of placing on part of a plant on or into a root, stem or branch of another plant (britannica). In cocoa, a part of elite plant material (scion) is grafted on seedlings or already mature trees (rootstock). Grafting is done to imrpove disease resistance, ensure flowering and many more characteristics of the plants.





Breeding:
The aim of breeding cocoa plants has been focussing on yield and disease resistance for years. By crossing the three types Criollo, Forastero and the hybrid Trinitario some major progress has been achieved. However, since the cocoa trees are still very susceptible to certain pest and diseases, like for example the swollen shoot virus in West Africa, further successful breeding methods need to be developed.

In the Ivory Coast, plant breeding and biotechnological projects have been established in 40 programs concerning all kinds of crops. Cocoa is one of the main crops in these programs. The breeding focusses on qualitative traits, favourable environments and biotic stress.
However, breeding facilities lack adequate equipment and laborartors infrastructure. That is the reason why advanced breeding techniques are very hard to implement. The lack of educated and trained plant breeders is also hindering the progress in breeding techniques. Additionally, the acces to public or private national genetic resources is limited.

References

Diby, L., Kouame, C., Kahia, J. W., & Betemariam, E. (2017). Tea, Coffee, and Cocoa. Retrieved 10 2018, from https://www.researchgate.net/publication/308792482_Tea_Coffee_and_Cocoa

ENCYCLOPÆDIA BRITANNICA. (2018). Graft, Horticulture. Retrieved 10 2018

Koffi, K. (2008). Plant breeding programs in Cote d’Ivoire. Retrieved 10 2018, from FAO: http://www.fao.org/in-action/plant-breeding/our-partners/africa/cote-divoire/en/

Sheaffer, C. S., & Moncada, K. M. (2012). Introduction to Agronomy. Delmar Cengage Learning.

Pictures:

Figure 1: https://content.ces.ncsu.edu/media/images/ag396-19.gif