PUCCINIA - WHEAT RUST - PLANT PATHOLOGY

1. PUCCINIA
 Classification:
Kingdom : Mycota
Subkingdom : Eumycotina
Division : Basidiomycotina
Class : Basisdiomycetes
Order : Uredinales
Family : Pucciniaceae
• Puccinia is an obligate parasitic fungus, which infects plants.
• Puccinia genus contains about 4000 species
• Wheat is infected by 3 species of Puccinia viz., Puccina graminis-tritici(
Black stem rust), P. recondita ( Orange/Brown rust) and P. striformis
(Yellow/ Stripe rust)
Dr P B Mallikharjuna ,GFGC Yelahanka, Bangalore 1

2. • Puccinia graminis - tritici is the most common species
• It causes black - stem rust disease in Wheat, an important staple
crop.
 Puccinia graminis- tritici
 It is an obligate parasitic fungus,
 In the absence of living host tissue, they survive as spores
 It is a macrocyclic, diphasic, polymorphic and heteroecious
fungus.
Dr P B Mallikharjuna ,GFGC Yelahanka, Bangalore 2
Uredosori Teleutosori Pycnia Acedia

3.  Macrocyclic fungus : It produces all types of spores (5 types)
1. UREDOSPORES (Asexual stage)
2. TELEUTOSPORES (Sexual apparatus / Resting spore)
3. BASIDIOSPORES,
4. PYCNIDIA- (Spermogonium- the Sexual Reproductive Stage)
5. AECIOSPORES-(Sexual stage)
 Diphasic fungus: It’s mycelium exists in both monokaryotic and dikaryotic
mycelial stages during its life cycle.
 Heteroecious: It completes its life cycle in two living host plants viz.,
1)WHEAT: edible crop, monocot, (Triticum aestivum) - (The primary
host) and
2)BARBERY: secondary host; dicot - weed ( Berberis vulgaris)
Dr P B Mallikharjuna ,GFGC Yelahanka, Bangalore 3

4. Puccinia on wheat:
• Wheat rust is one of the major and most devastating disease of wheat
across the globe
• Puccinia will attack the entire wheat plant, especially the leaves and
stem.
• Its mycelium is filamentous, multicellular, highly branched, dikaryotic,
intercellular with haustoria
• It produces two types of sporal stages in the wheat host.
1. Uredospores :The first spores to infect the young wheat
plants in the fall /summar are urediniospores. and
2. Teleutospores :Resting spores
Dr P B Mallikharjuna ,GFGC Yelahanka, Bangalore 4

5. 1.UREDOSPORES:
• This sporal stage is the prevalent stage generally
called Uredosorus.
• It represents the asexual reproduction stage
• These are long streaked red coloured
pustules, most commonly appear on the
wheat leaves and stems to some extant.
 Uredospores are usually ovoid in shape, single
celled, stalk bearing, thick walled spores.
 It is a binucleate cell with the two layered wall.
 The outer layer is thick and spiny, where as
inner layer is thin and smooth.
 4 - germ pores are present on its equatorial
zone.
 They are produced in the Uredinium or
Uredosorus (50,000- 400000spores/ uredinium)
Dr P B Mallikharjuna ,GFGC Yelahanka, Bangalore 5

6. 2. TELEUTOSPORES:
• Teliospores are produced in a
telium.
• Elongated blackish brown coloured
pustules produced more on the
stem and leaf sheath region.
 Teleutospores are bicelled , stalked,
spindle shaped, blackish -brown
coloured with bilayered thick and
smooth wall.
 Each cell is a binucleate and single
germ aperture containing structure
 It is a resting spore, which
represents the sexual apparatus in
which karyokinesis and meiosis
occurs later. TS of Wheat stem showing the Telutosorus of Puccinia
Telutospore
Dr P B Mallikharjuna ,GFGC Yelahanka, Bangalore 6

7. 3. BASIDIOSPORES: the infected
dried wheat straw containing
teleutospores will germinate
during favourable conditions and
produces a 4- celled Promycelium.
Later, each cell of the
promycelium produces a
basidiospore.
Dr P B Mallikharjuna ,GFGC Yelahanka, Bangalore 7

8. PUCCINIA ON BARBERY
1.It establishes in the Barbery plant by the
germination of Basidiospores.
2.Its mycelium usually present in the leaf region.
3.It is the primary and initially monokaryotic
mycelium usually confined to the upper portion of
the leaf
4.This fungus will produces two sporal stages on the
leaf i.e., the pycnidial stage on the upper surface
and the acedial stage towards the lower surface
Dr P B Mallikharjuna ,GFGC Yelahanka, Bangalore 8

9. Dr P B Mallikharjuna ,GFGC Yelahanka, Bangalore 9

10. VS of Barbery leaf
with Puccinia
Dr P B Mallikharjuna ,GFGC Yelahanka, Bangalore 10

11. THE PYCNIDIUM :
 After a few days, Puccinia will undergo sexual reproduction called Spermatogamy.
 Spermatogamy takes place between two spermogia or pycnidial cups belongs to
two different types (+, -)
 A typical spermogonium or pycnidial cup is usually possess numerous finger like
spermatophores in the middle portion surrounded by a long branched tubular
receptive hyphae.
 Spermatiophores are considered as the male structures, which produce spermatia
or male gametes
 While, the receptive hypha is considered to be the female reproductive structure
with a basal nucleus.
 When the spermatia is fallen on the receptive hypha, its nucleus penetrate into the
basal portion of the hypha and lie besides the female nucleus, it is known as
Diplodization ( Fertilization) Dr P B Mallikharjuna ,GFGC Yelahanka, Bangalore 11

12. ACEDIOSPORES:
 The dikaryotic mycelium is resulted
due to the diploidzation of the
monokaryotic hyphae, which grow
towards the lower epidermis and
establishes into the aeciospores.
AECIOSPORES
Dr P B Mallikharjuna ,GFGC Yelahanka, Bangalore 12

13. Dr P B Mallikharjuna ,GFGC Yelahanka, Bangalore 13