Detailed description about subphylum ustilaginomycotina has been explained in easy manner

1. USTILAGOMYCOTINA
N.H. SHANKAR REDDY
2nd Ph.D. Plant Pathology
Annamalai University

3. Ustilaginales > Smuts
Symptoms – Entire grain are replaced or converted into black
color powdery masses

4. Economically important pathogens include
Ustilago maydis (corn smut)
Tilletia controversa (dwarf bunt of wheat)
Tillieta tritici and T. laevis (common bunt)
Tilletia indica (Karnal bunt of wheat)
Urocystis agropyri (flag smut)

5. Corn smut - Ustilago maydis
• Formation on galls on ears, leaves, stalk or
tassels

6. Flag smut of wheat – Urocystis agropyri
Deformed tillers, infected plants gets twisted and later converted into black to brown colour
powdery masses

7. Difference between various smut diseases of sorghum
Particulars Grain smut Head smut Loose smut Long smut
Pathogen Sphacelotheca sorghi Sphacelotheca reliana Sphacelotheca cruenta Tolyposporium ehrenbergii
Symptoms Individual grains are
replaced by smut sori,
mostly of the ear got infected
The entire ear head/
inflorescence is completely
converted into smut spores
Majority of the ear portion
got affected
Small portion of the florets/
grains are infected
Sori Small Small Medium- Long Very Large
Columella Present (short) Absent Present (long black pointed
columella)
Absent
Site of infection Ovary Inflorescence Ovary Ovary
Diseases survival Externally seed borne Soil and seed borne Externally seed borne Air borne
Spore viability > 10 years 2 years 4 years 2 years
Management All these smuts can be managed by seed treatment with vitavax @ 2gm/ kg of seed

8. Write difference
between Rust and
Smut
Particulars Rust Smut
Description Rusty appearance on stems and
leaves
Entire grains are converted into
black colour powdery mass
Parasitism Obligate plant parasite Facultative saprophyte
Class Uredinales Ustilaginales
Perfect spore Terminal Intercalary
Number of
basidiospores per
mycelium
Four Many
Clamp connection
and secondary
mycelium
Rare Common
Heteroecism Common Absent
Polymorphism Distinct Absent
Nature Wheat rusts are heteroecious
and other rusts are autoecious
All smuts are autoecious
Hosts Two hosts in life cycle Only one host in life cycle
Number of spores Rust produce all 5 stages of
spores
pycniospores, aeciospores,
urediospore, teliospore and
basidiospores
All 5 stages of spores are absent