Diseases

Powdery mildew of Hydrangea serrata

Hydrangea serrata (Thunb.) Ser. var. serrata

A fungal disease of Hydrangea serrata caused by the pathogens Pseudoidium hortensiae and Golovinomyces orontii, manifesting as white powdery growth and purple leaf spotting.

In the reference 10 varieties crop Tea-of-heaven, where this is mentioned in the description.

The primary causal agents of powdery mildew on Hydrangea serrata are the fungi Pseudoidium hortensiae and Golovinomyces orontii. The disease affects both sides of the leaf blades and young shoots, causing their deformation, curling, and overall growth retardation of the plant.

A characteristic diagnostic sign of infection in Hydrangea serrata is the appearance of white or gray powdery growth, accompanied by purple or brown discoloration of the tissues. In advanced stages, the growth darkens, leading to premature leaf drop.

Specific resistance genes to the pathogen have not been isolated in this crop. During research, differentially expressed genes HydATP, HydCYSPRX, and HydUBC associated with the plant's response were identified; however, cultivar resistance is determined empirically through comparative trials.

General information about the subject — on the page Powdery mildew.

Sources8

Varieties of Tea-of-heaven mentioned in the description

Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.