Biology Reference
In-Depth Information
Fig. 1
Smut Spores.
Ustilago
(left), spiny
chlamydospore
germinating with
promycelium and sporidia
formed at sides;
Tilletia
(right), reticulate
chlamydospore with long
H-shaped sporidia formed
at end of promycelium and
sometimes forming small
secondary sporidia
wrecked off the Coast of England, but the cargo
of wheat was salvaged, free from bunt because of
its salt-water bath. Dark smut balls replace
kernels, and there is a fishy odor. Plants are
stunted, but not as much as with dwarf bunt.
Spore balls are broken in threshing and seed
contaminated. Many materials are offered for
seed treatment. Seed dealers treat seed for
farmers in special machinery at low cost.
Tilletia pallida
Bunt
on velvet and creeping
bent grass, Oregon, Rhode Island. Seeds are filled
with black spores, plants stunted. The disease is
serious where grass is grown for seed, with up to
80 % nonviable seed.
sterile spores on the surface, only a few fertile
spores. Sori without peridium.
Urocystis agropyri
Flag Smut
of wheat, also on
wheat grass, red top, and bluegrasses. Symptoms
are similar to those of stripe smut.
Urocystis anemones (including
U. hepaticae-
trilobae
).
Leaf and Stem Smut
of anemone,
hepatica, and trautveteria.
Urocystis carcinodes
Smut
of aconite, bane-
berry, clematis, and cimicifuga.
Urocystis colchici (Fischer includes
U. cepulae
in this species).
Leaf Smut
of autumn crocus,
camassia, Solomons-seal and false Solomons-
seal.
Urocystis gladiolicola
Gladiolus Smut
. This
disease had been intercepted several times at
quarantine and appeared once in California fields,
in 1950, but apparently is eradicated there.
Growers should be on the lookout for corms
with low blister swellings, with ridges paralleling
veins, bluish black, breaking open to expose
dense black spore balls. Seedlings exhibit blister-
ing, shredding, and necrosis of stem and leaf
tissues; they die if the disease is severe.
Urocystis kmetiana
Floral Smut
of field pansy
(
Viola bicoler
).
Urocystis magica (
U. colchici
).
Onion Smut
,
general on onion, also on leek, shallot, garlic,
and chives. This is the most destructive onion
disease, found in the Connecticut Valley as
early as 1861 and thence spread to all northern
onion-growing sections, but more important
where onions are grown from seed rather than
sets as in most home gardens. Black elongated
Urocystis
Tilletiaceae. Sori mostly in leaves and stems,
blackish; embedded in host tissues. Spore balls
permanent, without sterile cortex but sometimes
with a layer of hyaline, hyphal fragments. On
Liliaceae, Primulaceae.
Tuburcinia trienthalus (see
Urocystis
trientalus
).
Leaf and Stem Smut
of starflower.
Urocystis trientalus (formerly
Tuburcinia
trientalus
).
Leaf and Stem Smut
of starflower.
Urocystis
Tilletiaceae. Sori usually in leaves, stem sheaths,
occasionally in flowers; dark brown to black,
powdery to granular. Spore balls with distinct
