Symptoms and Signs on Ribes

Rusts

White Pine Blister Rust - Symptoms and Signs on Ribes

18181824.jpg (21442 bytes)

Ribes leaves infected with Cronartium ribicola. Uredinia are yellow spots on the leaves.

uredinia on Ribes

Uredinia (yellowish areas) produce urediniospores.

18181818.jpg (44078 bytes)

Another view of the uredinia produced on the lower surface of infected leaves.

18181833.jpg (15341 bytes)

Microscopic view of urediniospores. Note spiny appearance.

Urediniospores bliater rust

Scanning electron micrograph of urediniospores showing pointed projections on the spores.

18181822.jpg (42513 bytes)

Teila forming on leaf. Some uredinia can also be seen in the center of the photo.

telia of blister rust

By late summer, susceptable Ribes can have lots of telia on the lower leaf surface.

Telia on Ribes

Telia viewed with a hand lens on leaf surface. Basidiospores will be produced from the teliospores.

Basidiospores on Ribes

A stereophoto showing the basidiospores formed on basidia-like structures off of the telial column. Basidiospores reinfect pines.