USE OF MOLECULAR TOOLS FOR IMPROVING THE EFFICACY OF BIOLOGICAL CONTROL STRATEGIES FOR CACAO DISEASES
Project Number: 1275-21220-225-00
Start Date: Jul 10, 2007
End Date: Apr 22, 2012
Develop effective biological disease control strategies leading to sustainable yield improvements of cacao. This includes: determining the molecular mechanisms of action critical to the development of diseases caused by Moniliophthora spp. in cacao and identify potential targets for intervention, determining the mechanisms of action in the interactions between cacao, pathogens of cacao (Moniliophthora spp.), and Trichoderma isolates which result in effective disease suppression and improved plant productivity, and developing and optimizing strategies for biological control of cacao diseases caused by Moniliophthora spp.
The interactions between biocontrol agent, Trichoderma, isolates, cacao, and pathogens of cacao will be studied in detail. Diseases targeted for control include Witches’ broom (Moniliophthora perniciosa), and frosty pod (Moniliophthora roreri). Isolates of Trichoderma that aggressively colonize aerial cacao tissue (leaves, stems, flowers, flower cushions, and pods) epiphytically and/or endophytically and that possess strong biocontrol ability against one or more of the targeted pathogens will be identified. Trichoderma isolates from cacao ecosystems will be characterized for their mechanisms of biocontrol action including mycoparasitism, antibiosis and induced resistance. The impact of environment on Trichoderma colonization of aerial cacao tissues will be determined using specially adapted weather stations at 3 sites, and formulation technologies will be developed to ameliorate any negative effects. Formulation development will include established materials, techniques, and technologies along with novel approaches targeted to specific cacao tissues. Molecular techniques such as quantitative polymerase-chain reaction using RNA and DNA will be employed to optimize isolate selection and determine the impact of environment and formulation on biocontrol performance. A study of the pathogens’ genomes will be initiated to facilitate future research concerning their interactions with cacao and potential biocontrol agents. Ultimately, the best available isolates of Trichoderma based on mechanism of action, and epiphytic/ endophytic abilities, will be tested in combination with optimum formulations under field conditions and their efficacies at controlling cacao diseases determined.