Class seminar on wheat stem rust disease

1. Karthika, S., Kavin, C. and Kavinraja, P.
Pre-final B.Sc.(Ag.) 2017-18
Faculty of Agriculture
Annamalai University

2. Stem Rust also known as black rust, black stem rust, is caused
by the fungus Puccinia graminis f. sp. tritici.
The wheat rust fungi are obligate parasites, they grow and
multiply in nature only on living plant tissue.

4. De Bary clearly demonstrated that Puccinia graminis
required different hosts during the different stages
of its development (a phenomenon he called "heteroecism“)

6. Parts of Plant Infected: Commonly affects stems, leaf sheaths
and leaf blades; occasionally will affect parts of the head.
Shape and Distribution of Lesions: Oval-shaped or elongated
blister-like lesions scattered on affected tissues, lesions visible
on both sides of leaf.
Lesion Colour: Orange-red
Degree of Damage: Tearing of outer layers of plant tissue that
is visible without magnification.

7. Leaf infection

8. Stem infection

9. Stem infection

10. Head infection

11. Spermogonial stage

12. Aecial stage

13. Aeciospores

17. Disease Cycle: The alternate host of stem rust is the
common barberry, a plant in which the fungus may
overwinter and go through sexual recombination. The
stem rust fungus infects at warmer temperatures for
development near 26°C and development stopping at
temperatures above 37°C. A new, highly virulent race
group of the stem rust pathogen has been identified in
East Africa (originally referred to as race UG99).

19. Management: Resistance is the primary means of
control for stem rust.

20. Leaf rust
Stripe rust

21. Thank you!