This document discusses sugarcane mosaic virus (SCMV), a virus that infects sugarcane and other grasses. It was first observed in 1892 in Java and causes mosaic and necrosis symptoms. SCMV spreads through infected seed cane and aphid vectors like Rhopalosiphum maidis. Symptoms include chlorotic or yellow stripes on leaves that can lead to stunting and chlorosis of the entire plant. Management involves using resistant varieties, rogueing infected plants, and controlling aphid vectors through crop management.

1. COLLEGE OF AGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University, Coimbatore-3)
Kullapuram (Po),ViaVaigai Dam, Theni-625 562
SUGARCANE MOSAIC VIRUS
STUDENT
Miss. VIMALA V
ID. No. 2015021138
COURSE TEACHER
Dr. PARTHASARATHY S
Asst. Professor (Plant Pathology)

2. SUGARCANE MOSAIC VIRUS
Common Name : Mosaic of abaca.
Host : Corn, sorghum, certain millets and a
number of wild grasses.

3. HISTORY
• SCMV was first detected as an abnormility of sugarcane by
Van Musschenbroek (1892) in Java at the end of last century.
• He gave the name 'gelestrepenziekte' or yellow stripe disease
to this disorder of sugarcane.
• The role played by the virus in causing the disease was not
known at that time.

4. • Earle (1918) who first used the term 'mosaic’ for sugarcane
mosaic virus.
• Brandes reported (1919) the worldwide spread of mosaic in
the decade 1915-1925.

5. • The outbreaks of the disease with several losses in Puerto
Rico, later in Cuba and then in Louisiana State (U-S-A-)
stimulated research on the disease which eventually provided
answers to many of the questions regarding its nature and
importance.
• It was identified in 1919 by Brandes in U.S.A. who stated that
it brought severe losses to the industries and fanners.

6. • Brandes reported that the virus can be transmitted from
diseased to healthy plants with the corn leaf aphid,
Rhopalosiohum (formerly - Aphis) maidis (Fitch), as a vector,
and also by artificial inoculation technityies.
• Brandes and Klaphaak (1923) reported that many cultivated
and wild grasses are also susceptible to sugarcane mosaic
virus.

7. LOSSES
• SCMV is one of the important diseases affecting sugarcane
productivity. However the damage in the most countries is
controlled by replacement with the resistant varieties.
• Crop losses can vary from negligible to severe.
• King (1955-56) reported that mosaic caused heavy yield losses
in infected plantations to the tune of 39 to 46 %.

8. • In some commercial plantings of cv. Q95 from an infected
source, the infected plants had fewer tillers and were less
vigorous than apparently healthy plants nearby (Ryan and
Jones,1986).
• In the 1980s, losses on some farms in the Isis district of
Queensland, Australia, were estimated to be about 50% (Jones,
1987).

9. • The losses due to SCMV infection may vary, the extent
depending on the susceptibility to infection and tolerance of
the varieties to the effect of disease, on the strain of the virus
concerned and to some extent, on weather and other
environmental conditions influencing growth.

10. SYMPTOMS
• SCMV causes systemic infection of the sugarcane plant:
the whole plant, including roots, contains virus.
• However, the symptoms (mosaic and/or necrosis) are
observed on the leaves and sometimes the stems.

11. • The disease appears more prominently on the basal portion of
the younger foliage as chlorotic or yellowish stripes alternate
with normal green portion of the leaf.
• As infection becomes severe, yellow stripes appear on the leaf
sheath and stalks.
• Elongated necrotic lesions are produced on the stalks and
stem splitting occurs.

12. • The necrotic lesions also develop on the internodes and the
entire plant becomes stunted and chlorotic.
• Sometimes the whole plant is stunted and chlorotic, easily
identified from a distance.

13. ©www.agdia-biofords.com

14. Mosaic symtoms on leaves

15. Mosaic symptoms on leaves

16. Pathogen:
• Sugarcane mosaic virus (Marmor sacchari) is present in
abundance in the chlorotic lesions of the affected leaves.
• It belongs to the potato virus Y group.
• It causes varying degrees of destruction of the chlorophyll, and
hence the chlorotic symptom.

17. • The virus particles are rods, measuring in the range of 650-
770×12-15 µm.
• Several strains of the virus, designated as A,B,C,D,E,F and H
and a few sub-strains have been differentiated, based on their
physical properties and virulence.

18. SYSTEMATIC POSITION
Domain: Virus
Unknown: "Positive sense ssRNA viruses"
Unknown: "RNA viruses"
Family: Potyviridae
Genus: Potyvirus
Species: Sugarcane mosaic virus

19. Mode of spread
• There are three principal modes of spread of SCMV: (1) by
aphid vectors, (2) by infected seed cane and (3) by mechanical
inoculation.
• Only aphid vectors and infected seed cane are important in the
field. Mechanical transmission, for the most part, is important
only in greenhouse and laboratory research.

20. • Once the virus is inside the susceptible host tissues, it becomes
systemic.
• The incubation period varies from 7 to 20 days, depending
upon the host variety and virus strain.
• The virus spread, both from the leaves to the stem and from
the stem to the leaves, and to other shoots in the clump.

21. • According to Charpentier (1963) a close relationship exists
between ants and the known vectors of the disease.
• This is because the honey excreted by the aphids is a good
food for the ants and these carry the aphid from one sugarcane
plant to another plant as well as the grass to the cane and vice
versa.
• These ants built dirt and bore-frass covering over the colonies
of aphids to protect them from parasites and weather.

22. • Needle-like mouthparts or stylets of the vectors pierce plant tissues
and suck up the plant sap.
• The plant tissues are not destroyed by this type of feeding but saliva
is ejected into the plant cells.
• Once the virus has entered and established, the infection is carried to
all parts of the plant.
• The typical mottling symptoms appear on the new leaves that are
formed after the infection.

23. Rhopalosiphum maidis
©www.nbair.res.in

24. Factors favouring development
• Disease incidence is highest where vector populations are
high, a large number of infected plants are present, and
susceptible varieties are cultivated.

25. Management
• Crops of maize and sorghum are good hosts of vectors such as
Rhopalosiphum maidis, and should not be grown near infected
sugarcane crops.
• Altering the times of planting and harvesting so that they do
not coincide with high aphid vector populations can reduce
losses (Bailey and fox, 1980).

26. Management
• Eradicate SCMV by roguing infected plants have rarely been
successful (Abbott, 1961; Koike and Gillaspie, 1989).
• Saccharum spontaneum L. and S. barberi (Jesweit) carry
resistance to mosaic and so varieties with this background
must be preferred.
• The spontaneum canes from java posses a high degree of
resistance to mosaic.

27. Management
• The use of resistant varieties is the most effective method of
mosaic control.
• Planting mosaic-free seed cane is essential.
• Rogue out the diseased clumps periodically. Select setts from the
healthy fields as the virus is sett-borne Aerated Steam Therapy
(AST) at 56°C for 3 hrs, for setts before planting is advised.