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Elimination of plant pathogens:

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Plant pathogens:

Nematodes, Fungi, Bacteria, Nematodes, Rikettsia,

Mycoplasma, Viruses and Viroids.

can be transmitted from diseased to healthy

plants.

Pathogen tested Plants

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Disease Triangle:

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Selection of uninfected Parts:

Geminivirus infection on leaf of Eupatorium makinoi

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Selection of uninfected Parts:

Vitis vinifera infected with ascomycete fungus Eutypa lata

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Elimination of plant pathogens:

Powdery Mildew(Fungal)

Place plants in the propergrowing site with good air

circulation. Avoid shady humid areas. Follow good sanitation

practices. Avoid over fertilization and

watering.

Aphids (Insect)

Control:

Insect predators such as lady

beetles, lacewings, syrphid flies

and parasitic wasps.

Fungi that attack aphids.

Plain water from a hose can

wash them off.

Insecticides.

http:/

/urbanext.illinois.edu/containergardening

/problems.cfm

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Meristem Culture:

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Meristem Culture

Meristem isolation and culture:

Meristem

viral free culture ?

High metabolic activity

Lack of vascular system

High auxin conc.

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VIRUS ELIMINATION

THERAPY

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1. Thermotherapy

Preconditioning at HighTemp.

37 to 380C for 2 t0 4weeks

Buds raise virus freeplants

Virus elimination procedure:

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Heat Treatment

Replication issignificantly Reducedat elevatedtemperature.

Production of viralmovement protein andcoat protein are temp.

sensitive

Temp.

30 to 50 0C

Methods:

Water soaking

Expose to hot

air Expose to

aerated steam

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1.Thermotherapy:

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2. Cryo-therapy:

Prolonged exposure of shoot tip culture to a low temperature (5 0C) .

E.g. In chrysanthemum, shoot tip culture exposed with 50C for

4 months.

Result:

67 % free from chrysanthemum stunt virus (CSV)

22% were free from chrysanthemum chloritic mottle virus (

CCMV).

The frequency is increased to 73 % in case of CSV and to 49

percent in CCMV after 7.5 months exposure to 5 0C.

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3. Chemo-therapy:

Incorporation of antiviral drugs into the culture mediumfor curing the shoot tips virus.

eg: Virazole, 2-thiouracil, Cyclohexamide.

Virazole: nucleoside analogue broad spectrum against animal DNA and RNA

viruses

Ribavirin: Guanosine analogue

DHT( %-dihydroazauracil): uracil analoge

shown variable results when applied to the potatoplant as spray or in hydroponiz culture followed bymeristem culture.

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SURFACE STERILIZATION :

Ethanol (Alcohol)

Mercuric chloride.

Bactericides and fungicides.

Antibiotics Gentamycin

Rifampicin

Nystatin + Carbenecillin

Gentamycin + Amphotericin B Vancomycin-HCI + Mycostatin

Streptomycin + Carbenecillin

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Production of materials with in theNursery:

http://www.iht.edu.in/mgt-616.html

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Growing seedlings:

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Reference:

Plant Product Biotechnology By P.R. Yadav

http://pdf.usaid.gov/pdf_docs/PNAAW412.pdf

http://pdf.usaid.gov/pdf_docs/PNAAW412.pdfhttp://pdf.usaid.gov/pdf_docs/PNAAW412.pdfhttp://pdf.usaid.gov/pdf_docs/PNAAW412.pdfhttp://pdf.usaid.gov/pdf_docs/PNAAW412.pdf