Histopathological studies for powdery and downy mildew pathogens of grapevine

Grapevine (Vitis vinifera l.) is an essential commercial fruit crop and one of the most widely cultivated crops in the world. Powdery and mildews seriously affect the grapes cultivation and cause higher economic loss. Present study was conducted to find out the histological changes due to the infection by these pathogen. Microtomy sections of healthy grapevine leaves showed regular arrangement of epidermal cells, cortical parenchyma cells, conducting vessels and pith cells. in the infected leaf by Plasmopara viticola, thickening of cell wall was pronounced and cytoplasm was dense and granular. The infection by Uncinula necator led to collapse of epidermal cells, disruption of mesophyll and guard cells. in addition, large cavities were also found in the cytoplasm.