The control of brown spot of pear caused by Stemphylium vesicarium (Pleospora allii), is mainly based on numerous chemical treatments. However, new perspectives are offered by the integration with biological products based on Trichoderma, which has been showed to reduce the pathogen inoculum on the orchard floor. The aim of this study was to test the competitive interaction and the mechanisms of action of several biocontrol agents against S. vesicarium. We considered the biofungicides Rootshield (Trichoderma harzianum T22), Remedier (T. asperellum ICC012 and T. gamsii ICC080), Trichover (T. harzianum ITEM 908), Mycostop (Streptomyces griseoviridis K61) and Serenade (Bacillus subtilis QST713). Each microorganism was tested for substrate colonization and inhibitory effect against the pathogen. T. harzianum T22 and S. griseoviridis K61 were the most active in inhibiting the pathogen mycelial growth, while T. harzianum ITEM908 showed the highest substrate colonization. Trichoderma strains exhibited parasitic action of pathogen hyphae, visible as coiling, lysis and collapse. All microorganisms produced chitinolytic enzymes. B. subtilis QST713 produced the highest level of glucosaminidase, S. griseoviridis K61 the highest level of chitobiosidase and T. asperellum ICC012 the highest level of endochitinase. Non volatile metabolites produced by T. harzianum T22, S. griseoviridis K61 and B. subtilis QST713 on PDA were the most active in reducing the pathogen mycelial growth. Metabolites caused also morphological alteration of hyphae. Metabolites from liquid culture of the microorganisms, did not reduce conidia germination, but reduced the number of germ tubes/conidia (B. subtilis QST713) and their elongation (T. asperellum ICC012 and T. gamsii ICC080).
R. Roberti, A. Veronesi, G. Alberoni, A. Brunelli. (2009). POTENTIAL OF BIOFUNGICIDES FOR THE CONTROL OF STEMPHYLIUM VESICARIUM ON PEAR.
POTENTIAL OF BIOFUNGICIDES FOR THE CONTROL OF STEMPHYLIUM VESICARIUM ON PEAR
ROBERTI, ROBERTA;ALBERONI, GIULIA;BRUNELLI, AGOSTINO
2009
Abstract
The control of brown spot of pear caused by Stemphylium vesicarium (Pleospora allii), is mainly based on numerous chemical treatments. However, new perspectives are offered by the integration with biological products based on Trichoderma, which has been showed to reduce the pathogen inoculum on the orchard floor. The aim of this study was to test the competitive interaction and the mechanisms of action of several biocontrol agents against S. vesicarium. We considered the biofungicides Rootshield (Trichoderma harzianum T22), Remedier (T. asperellum ICC012 and T. gamsii ICC080), Trichover (T. harzianum ITEM 908), Mycostop (Streptomyces griseoviridis K61) and Serenade (Bacillus subtilis QST713). Each microorganism was tested for substrate colonization and inhibitory effect against the pathogen. T. harzianum T22 and S. griseoviridis K61 were the most active in inhibiting the pathogen mycelial growth, while T. harzianum ITEM908 showed the highest substrate colonization. Trichoderma strains exhibited parasitic action of pathogen hyphae, visible as coiling, lysis and collapse. All microorganisms produced chitinolytic enzymes. B. subtilis QST713 produced the highest level of glucosaminidase, S. griseoviridis K61 the highest level of chitobiosidase and T. asperellum ICC012 the highest level of endochitinase. Non volatile metabolites produced by T. harzianum T22, S. griseoviridis K61 and B. subtilis QST713 on PDA were the most active in reducing the pathogen mycelial growth. Metabolites caused also morphological alteration of hyphae. Metabolites from liquid culture of the microorganisms, did not reduce conidia germination, but reduced the number of germ tubes/conidia (B. subtilis QST713) and their elongation (T. asperellum ICC012 and T. gamsii ICC080).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
