From my collection of Curvularia fungi isoaltes I want to check pathogenicity. Which crop/age of seedlings/techniques of inoculation I may use to get best result?
The pathogenicity of Curvularia species will depend on getting a range of isolates and getting clear identification of these. Curvularia is a big issue on sorghum in tropical areas especially seed germination and quality are concerns.
When inoculating the plants appropriate stages are important. Curvularia is a virulent pathogen on sorghum seeds infection is probably occurring at or after the stigma is extruded. You may want to test inoculation at different stages that determine the best period for determining resistance levels.
There are different species involved and these would need to be differentiated. The infection of Curvularia species occurs from flowering on and it will respond to environmental conditions.
Curvularia is involved in the African Yam Dioscorea rotundata and the pathogenicity can be tested through foliar inoculation and rating. Using a time sequence after inoculation and clearing and staining the test leaves will give a view of pathogenesis.
The use of a million conidia per ml would be a good inoculum level to use for either of these projects. The use of tilt fungicide during the critical periods of infection can create levels of incidence and severity to analyze the epidemiology and damage effect. For instance in critical infection stages application of 0, 1, 2 and 4 applications would give assessment of disease damage curves and development.