“Control of tomato damping-off caused by Sclerotium rolfsii by using the plant growth-promoting bacterium Pseudomonas sp. PCI2”.

PASTOR NICOLÁS, REYNOSO MARÍA M., TONELLI MARÍA LAURA, MASCIARELLI OSCAR, ROSAS SUSANA B., ROVERA MARISA

JOURNAL OF PLANT PATHOLOGY

EDIZIONI ETS

Año: 2010 p. 1 - 5

1125-4653

Fluorescent Pseudomonas spp. from the root systems of healthy tomato plants were isolated. Isolates were screened for their antagonistic activities against three phytopathogenic fungi of tomato and pepper plants, Sclerotium rolfsii,  Alternaria alternata  and  Fusarium solani. Phosphate solubilization and production of siderophores, hydrolytic enzymes, indole 3-acetic acid  and hydrogen cyanide were  also tested. In addition, isolates were characterized by biochemical (API 20NE test) and genotypic (ERIC-PCR fingerprinting) features. Pseudomonas sp. PCI2 was chosen as a potential candidate for control of tomato damping-off caused by Sclerotium rolfsii. PCI2 was identified at the genus level with a 16S rDNA partial sequence analysis; also, the phylogenetic relationship among the selected isolate and previously characterized species of Pseudomonas was determined. PCI2 clustered with the P. putida species. Growth chamber studies resulted in statistically significant increases in plant stand (29%) as well as in root dry weight (58%). Pseudomonas sp. PCI2 was able to establish and survive in tomato plants rhizosphere after 40 days following planting of bacterized seeds. Results indicated that isolate PCI2 is a potential biological control agent that may contribute to the protection of tomato plants against damping-off caused by S. rolfsii.