PAT 201

1. COURSE TEACHER
Dr. PARTHASARATHY S
Asst. Professor (Plant Pathology)
STUDENT
K.K. SUJAYBRAHATHEESH
ID. NO. 2017021075
COLLEGE OF AGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University, Coimbatore-3)
Kullapuram (Po),ViaVaigai Dam, Theni-625 562
SYMPTOMS, HOST RANGE,
TAXONOMY AND LIFE CYCLE OF
SAROCLADIUM

2. SAROCLADIUM
• Sarocladium presently encompasses 10 species.
• Sarocladium oryzae, the type species of the genus, is
an important plant pathogen causing sheath-rot of rice
(Oryza sativa).
• It is also known to produce antimicrobial secondary
metabolites, such as helvolic acid and cerulenin.

3. TAXONOMY
Domain: Eukaryota
Kingdom: Fungi
Phylum: Ascomycota
Subphylum: Pezizomycotina
Class: Sordariomycetes
Subclass: Hypocreomycetidae
Order: Hypocreales
Genus: Sarocladium
Species: S. oryzae

4. SAROCLADIUM ORYZAE
• Sarocladium oryzae (Sawada) is a plant pathogen
causing the sheath rot disease of rice.
• In culture it produces 0.3
0.627 micrograms of helvolic acid and 0.9-
4.8 micrograms of cerulenin per milliliter of culture
medium.
• The level of helvolic acid correlated with a higher
incidence of sheath rot disease.

5. SAROCLADIUM ORYZAE
• Rice grains from infected plants were found to
contain 2.2 micrograms helvolic acid and 1.75
micrograms of cerulein per gram of infected seeds,
which induce chlorosis and reduce the seed viability
and seedling health.
• S. oryzae has also been known as Acrocylindrium
oryzae (Sawada).

6. SYMPTOMS
• Discoloration in the flag
leaf sheath

7. SYMPTOMS
• Rotting occurs on the
leaf sheath that encloses
the young panicles.
• Irregular spots or
lesions, with dark
reddish brown margins
and gray center.

8. SYMPTOMS
• Severe infection causes
entire or parts of young
panicles to remain
within the sheath

9. SYMPTOMS
• Lesions enlarge and often coalesce and may cover the
entire leaf sheath.
• Unemerged panicles rot and florets turn red-brown to
dark brown.
• Whitish powdery growth inside the affected sheaths
and young panicles.

10. SYMPTOMS
• Infected panicles
and grains are sterile,
shriveled, partially or
unfilled, and discolored.
• The disease is important
during the heading
towards the maturity
stages of the rice crop.

11. SYMPTOMS

12. SYMPTOMS

13. SYMPTOMS

14. HOST RANGE
The Host Range of this pathogen has not been studied.
Few reports are only avaliable
• Balakrishnan and Nair (1981) reported that field
weeds Cyperus diformis, Echinocholoa crusgalli,
Monochoria vaginalis and Cyperus teneriffe were
naturally infected hosts of S. oryzae .
• Echinocholoa colona, was also found to play a role as
an alterate host for this pathogen

15. LIFE CYCLE

16. LIFE CYCLE
• The fungus produces white
mycelium, sparsely branched,
septate, and measures 1.5-2mm
in diameter.
• Conidiophores arising from the
mycelium are slightly thicker
than the vegetative hyphae,
branched once or twice, each
time with 3-4 branches in a
whorl.

17. LIFE CYCLE
• The fungus invades rice through the plant's stomata and
wounds and grows intercellularly in the vascular bundles
and mesophyll tissues.

18. REFERENCES
• Alice D, Jeyalakshmi C, Krishnamoorthy A.S and Karthikeyan
M, 2017. Fundamentals of Phyto Pathology. Sri Sakthi
Promotional Litho Process, Coimbatore.
• https://www.cabi.org/isc/datasheet/48393
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4510268/
• https://en.wikipedia.org/wiki/Sarocladium_oryzae
• http://www.agritech.tnau.ac.in/expert_system/paddy/cpdissrsb.
html
• http://krishikosh.egranth.ac.in/handle/1/89295