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Recent changes in cotton leaf curl disease complexes; are we heading

Towards another epidemic?

Dr. Shahid Mansoor, S.I

Agricultural Biotechnology Division,

National Institute for Biotechnology and Genetic

Engineering (NIBGE), Faisalabad, Pakistan

Cotton leaf curl virus has great impact on economy Ø Pakistan loses 3 million bales (Equivalent to Rs. 120 billion per year) Ø Other losses are seed, oil, seedcake Ø Net importer of cotton

Geminivirues are a global threat • Cassava mosaic disease in Africa • Cotton leaf curl in Pakistan • Beans in India and South America

Geminiviridae

•  Mastrevirus •  Curtovirus •  Topocuvirus •  Begomovirus

MP

CP

RepA

RepB

C4

V2 MP

C2 REn Rep

CP

C4

Rep C2

C3

V2

DNA B

MP NSP

DNA A

V2

C4

Rep TrAP REn

CP

CP

Cotton leaf curl virus epidemic in Pakistan Epidemic level in 1992 Heavy losses to Pakistan cotton (5 billion US dollars)

Virus impact

Begomoviruses known before

Begomoviruses discovered by us

Begomovirus species associated with cotton leaf curl disease Cotton leaf curl Multan virus Cotton leaf curl Alaabad virus Cotton leaf curl Khokhran virus Cotton leaf curl Rajasthan virus Sequence analysis suggest that some of these are recombinants

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Distinct begomoviruses associated With Cotton leaf curl disease interact with cotton beta

C1 GENE A-RICH SCR

Geminivirus disease complexes on cotton

Begomovirus disease complex Monopartite begomoviruses with satellites Common in Asia/Africa Bipartite begomoviruses Found in Americas

Phylogenetic relationships of cotton begomoviruses

New World

Africa

Asia

What we learned? DNA beta interacts with distinct begomoviruses and mobilize them in cotton How quickly it is happening? What are the consequences?

How quickly geminivirus disease complexes are evolving ????

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How quickly? New species associated with the disease Papaya leaf curl virus Tomato leaf curl Karnataka virus Experimental interaction Ageratum yellow vein virus Singapore Tomato leaf curl virus Australia Consequences? Resistance breakdown? Changes in host range?

The spread of Burewala virus 2001-2003

The spread of cotton leaf curl virus (1991-1996)

Breakdown of resistance in cotton

The spread of Burewala virus 2001-2008

The spread of cotton leaf curl virus (1991-1996)

Breakdown of resistance in cotton DNA A

V2

C4

Rep TrAP

REn

Cotton leaf curl Kokhran virus

CP

DNA A

V2

C4

Rep TrAP

REn

Cotton leaf curl Multan virus

CP

DNA A

V2

C4

Rep

REn TrAP

CP

Cotton leaf curl Burewala virus

Burewala strain 2001-2008

Conclusions ü Geminivirus disease complexes are evolving rapidly

ü Pose a serious threat to world agriculture

Why? International trade TYLCV from Israel to North America SqLCV from North America to Israel Cotton beta can interact with local viruses Bioterrorism?

Serious threat to world agriculture

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Who is at risk? Where whiteflies have established as pest Indian subcontinent Australia China Americas Southern Europe

Viruses in Sindh 2009-2010

Cotton leaf curl complexes in Sindh Cotton leaf curl Shahdadpur virus Along with Cotton leaf Shahdadpur alphasatellite Cotton leaf curl Multan betasatellite But the most strange is

Cotton leaf curl Gezira virus

Related to CLCuGV from Egypt

CLCuGV is found with Multan betasatellite and Chilli leaf curl betasatellite

CLCuGV interacts with both betasatellites from Pakistan

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Possible land and sea routes for introduction 2009-2010 A new complex

emerging in Punjab??

Changes in the complex in Punjab Presence of alphasatellites in Punjab Presence of chilli betasatellite in cotton sample along with cotton betasatellites Is it a synergism involving satellites?

Take home message • Cotton leaf curl complex is adopting rapidly (against resistance) •  Require broad-spectrum resistance •  Gene pyramiding for durable solution § Team effort will win against this menace