A NEW APPROACH TO EXTEND THE LIFE SPAN OF UNCINULA NECATOR GROWING IN VITRO

Uncinula necator (Sch.) Burrill is the obligate fungal pathogen responsible for powdery mildew in grapevine (Vitis vinifera). U. necator spores may be germinated in vitro for up to 48 h, which while being useful for a laboratory assay of potential fungicides, makes it very difficult for further studies on this fungus.
Extraction of proteins from grapevine leaves is difficult probably due to the presence of phenolic compounds.
Recent evidence indicates that grapevine leaf protein extraction is dramatically enhanced when the leaves are infected with U. necator indicating that this fungus depletes phenolic compounds in leaves.
We have determined that the concentration of several phenolic compounds, including tannins, was considerably lower in infected leaves compared to healthy ones.
We also found that there was a better and faster spore germination and germ tube growth in a growth media mixed with grape leaf extract.
In this study, we attempted to identify the most relevant leaf compounds necessary for the development of U. necator infection and to use them in an in vitro media to promote a longer life span for this fungal pathogen.

VII International Symposium on Grapevine Physiology and Biotechnology

S. Monteiro, R. Freitas, A. Teixeira, R. Ferreira

Uncinula necator, Vitis spp., phenolic compounds

https://doi.org/10.17660/ActaHortic.2005.689.12