Fig. 220.
Germinating uredospore of wheat rust.
(After Marshall-Ward.)
Fig. 221.
Germ tube entering the
leaf through a stoma.
407a. Teleutospores the last stage of the fungus in the season.—The teleutospores are developed late in the season, or late in the development of the host plant (in this case the wheat is the host). They then rest during the winter. In the spring under favorable conditions each cell of the teleutospore germinates, producing a short mycelium called a promycelium, as shown in figs. [222], [223]. This promycelium is usually divided into four cells. From each cell a short, pointed process is formed called a “sterigma.” Through this the protoplasm moves and forms a small gonidium on the end, sometimes called a sporidium.
Fig. 222.
Teleutospore
germinating,
forming
promycelium.
Fig. 223.
Promycelium
of germinating
teleutospore,
forming sporidia.
Fig. 224.
Germinating
sporidia
entering
leaf of
barberry by
mycelium.