Author
DE SOUZA, J - BRAZIL | |
BOWERS, J - MD DEPT OF AGRI | |
Samuels, Gary | |
HEBBSR, P - MASTERFOODS,N BRUNSWK,NJ | |
POMELLA, A - BRAZIL |
Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 4/30/2003 Publication Date: 6/1/2003 Citation: De Souza, J.T., Bowers, J.H., Samuels, G.J., Hebbsr, P.K., Pomella, A. 2003 Genetic diversity and activity of Trichoderma stromaticum, a myco-parasite of the cocoa witches' broom pathogen. Phytopathology. 93:S20 Interpretive Summary: Witches’ broom, caused by Crinipellis perniciosa, inflicts severe damage in cocoa plantations in Central and South America. In Brazil, a commercial formulation of Trichoderma stromaticum is being used in the field. However, performance has been inconsistent. One strategy to improve biocontrol is to exploit the diversity of microorganisms belonging to the same species. We collected 95 T. stromaticum isolates from Bahia and the Amazon region. Diversity was studied using AFLP and RAPD analyses. All the isolates collected from Bahia were genetically similar and related to the commercial isolate. Isolates from the Amazon region were more diverse. Mycelial growth at different temperature and on saline media, and sporulation at 30 C and on brooms varied greatly among the isolates. Several isolates showed superior activity in vitro when compared to the commercially available one. Field studies to relate in vitro activity to biocontrol efficacy are ongoing. Technical Abstract: Witches’ broom, caused by Crinipellis perniciosa, inflicts severe damage in cocoa plantations in Central and South America. In Brazil, a commercial formulation of Trichoderma stromaticum is being used in the field. However, performance has been inconsistent. One strategy to improve biocontrol is to exploit the diversity of microorganisms belonging to the same species. We collected 95 T. stromaticum isolates from Bahia and the Amazon region. Diversity was studied using AFLP and RAPD analyses. All the isolates collected from Bahia were genetically similar and related to the commercial isolate. Isolates from the Amazon region were more diverse. Mycelial growth at different temperature and on saline media, and sporulation at 30 C and on brooms varied greatly among the isolates. Several isolates showed superior activity in vitro when compared to the commercially available one. Field studies to relate in vitro activity to biocontrol efficacy are ongoing. |