Development of a marker assisted selection program for cacao

Area of Science:

• Plant Pathology
• Agricultural Science
• Genetics

Background:

• Cacao production in tropical America faces significant losses from fungal diseases: witches' broom (Moniliophthora perniciosa), frosty pod (M. roreri), and black pod (Phytophthora spp.).
• These diseases caused over $700 million in losses in 2001, impacting global cacao supply chains.
• While West Africa and South Asia are not yet affected by witches' broom and frosty pod, their cacao varieties are susceptible.

Purpose of the Study:

• To develop new cacao cultivars resistant to major fungal diseases.
• To implement a marker-assisted selection (MAS) program for identifying disease resistance.
• To confirm the utility of identified genetic markers in breeding programs.

Main Methods:

• Identification of quantitative trait loci (QTL) associated with resistance to witches' broom, frosty pod, and black pod.
• Development and application of a marker-assisted selection (MAS) program.
• Validation of marker effectiveness in an experimental F(1) family in Ecuador.

Main Results:

• Quantitative trait loci conferring resistance to witches' broom, frosty pod, and black pod were successfully identified.
• The identified markers demonstrated potential for selecting disease-resistant cacao individuals.
• Experimental validation in an F(1) family confirmed the usefulness of these markers.

Conclusions:

• Marker-assisted selection (MAS) is a viable strategy for developing disease-resistant cacao cultivars.
• The identified genetic markers provide a valuable tool for accelerating breeding programs against major cacao pathogens.
• This research contributes to safeguarding cacao production against devastating fungal diseases.