Rusts
White Pine Blister Rust - Symptoms and Signs on Ribes
Ribes leaves infected with Cronartium ribicola. Uredinia are yellow spots on the leaves.
Uredinia (yellowish areas) produce urediniospores.
Another view of the uredinia produced on the lower surface of infected leaves.
Microscopic view of urediniospores. Note spiny appearance.
Scanning electron micrograph of urediniospores showing pointed projections on the spores.
Teila forming on leaf. Some uredinia can also be seen in the center of the photo.
By late summer, susceptable Ribes can have lots of telia on the lower leaf surface.
Telia viewed with a hand lens on leaf surface. Basidiospores will be produced from the teliospores.
A stereophoto showing the basidiospores formed on basidia-like structures off of the telial column. Basidiospores reinfect pines.