Fungal diversity of cocoa (Theobroma cacao) in Cuba : from field to fermentation
(2015)
Files
ThesisYurelkysFernandez_Fungaldiversitycocoa.pdf
Open Access - Adobe PDF
- 5.11 MB
Details
- Authors
- Supervisors
- Abstract
- In Cuba, a national program intends to rehabilitate the cocoa sector. The objective is to reinforce the production chain of cocoa and to support a protected designation of origin. One of the actions for the sustainable development of cocoa in the Cuban environmental and economic context requires a rational and integrated control of pathogens affecting productivity and bean quality. Black pod disease caused by several Phytophthora species is the most damaging disease in cocoa production areas in Cuba. In the present work, we studied a set of Phytophthora strains isolated from diseased pods originating from Cuba, combining morphological, biological and molecular approaches to identify the species involved. Our results showed that two species are damaging cocoa plantations in Cuba, viz. P. palmivora and P. tropicalis. Different forms of crop protection are employed to reduce the impact of this disease, cultural practices such as pod stripping and the use of pesticides. However, biological control is an important alternative. Nowadays, fungal endophytes seem to be an interesting option for black pod disease control. In this study fungal endophytes present in cocoa were identified to potentially use them in the context of integrated management systems for disease control. Our findings highlight the possibility to use the endophytic fungus Colletotrichum gloesporioides as biological control agent against black pod disease. Proper control of the disease would strengthen cocoa plantations and reduce crop losses, increasing the quantity of healthy cocoa pods. Healthy cocoa pods are the starting material for cocoa bean fermentation, the first step in the production of chocolate and crucial for the final chocolate flavor. Without fermentation there will not be any chocolate flavor. The fermentation of cocoa beans is a well-defined microbial succession that is dominated by yeast during the first hours. In the current work, the yeast diversity of spontaneous cocoa bean fermentation heaps in east Cuba was investigated. Yeasts were isolated from eight fermentations and their environments such as surfaces, tools, insects and plants. The most frequently detected species were P. manshurica, Hanseniaspora opuntiae, and P. kudriavzevii. Seventeen potentially new species were discovered, of which two, referred to as Yamadazyma sp. and Saccharomycopsis cf. crataegensis, were isolated repeatedly from fermentations and equipment.
- Affiliations
