Well-done!

For the urediniospores, they can infect wheat repeatedly, by spreading to the other part of same wheat or different one and forming a new uredinium. In addition, uredinia (brick-red) are commonly found at leaf sheaths, but are also found on stems, leaves.

For the teliospores, they have thick-cell wall, so they are able to tolerate the cold winter. Afterward, they would undergo karyogamy and meiosis, which become basidiospores.

Question: Telium is derived from uredinium directly or not? If not, then how is the telium formed? If yes, what is the stimulation to cause the conversion?