Giuseppa Rosaria Leonardi
PhD Student
Department of Agriculture, Food and Environment (Di3A), University of Catania
Catania, Sicilia, Italy
Amanda Vaccalluzzo
Research fellow
Department of Agriculture, Food and Environment (Di3A), University of Catania
Catania, Sicilia, Italy
Giorgio Gusella
Assistant professor
Department of Agriculture, Food and Environment (Di3A), University of Catania
Catania, Sicilia, Italy
Alessandra Pino
Assistant professor
Department of Agriculture, Food and Environment (Di3A), University of Catania
Catania, Sicilia, Italy
Dalia Aiello
Associate professor
Department of Agriculture, Food and Environment (Di3A), University of Catania
Catania, Sicilia, Italy
Cinzia Lucia Randazzo
Full professor
Department of Agriculture, Food and Environment (Di3A), University of Catania
Catania, Sicilia, Italy
Giancarlo Polizzi
Full professor
Department of Agriculture, Food and Environment (Di3A), University of Catania
Catania, Sicilia, Italy
Plenodomus tracheiphilus, the causal agent of mal secco disease, is considered as the major destructive disease affecting lemon, with serious economic impact on citrus industry of the Mediterranean and Black Sea regions. Several Bacillus strains have been identified as biocontrol agents. In this study seedlings of volkamerian lemon were treated with the formulate Serenade®Aso containing Bacillus amyloliquefaciens QST713 to investigate its endophytic colonization ability on leaf and stem tissues after foliar application, at three different representative timings: 7, 14, and 21 days. Presence of BCA was detected and quantified using both the culture-plate method, by spreading on artificial media, and molecular qPCR assay, with species-specific primer pair. Results derived from both evaluation methods reported similar trend for BCA concentration over time, revealing better colonization ability in stem tissue at 21 days. Specifically, the culture-dependent method showed average values at 21 days of 2.43 ± 0.21 Log CFU g-1, and of 4.64 ± 0.10 Log CFU g-1 for leaf and stem tissue, respectively. Quantitative PCR assay showed average values close to 6.46 ± 0.13 copies Log CFU g-1 for leaf tissue and 7.72 ± 0.56 copies Log CFU g-1 for stem tissue, both at 21 days of inoculation. The interest in using BCAs in an integrated management of citrus diseases is increasing due to the further restrictions on the usage of copper by the European Union. The knowledge on BCAs population dynamics over time within the plant system is essential to achieve a satisfactory disease management.