Father of Plant Pathology

Anton de Bary

Father of Microbiology

Louis Pasteur

Father of Antibiotics

Alexander Fleming (1929) – discovered Penicillin

First bacterial disease in plants discovered

Fire blight of pear

First transgenic plant

Tobacco

Crystallization of virus particles (TMV)

W.M. Stanley (1935)

Gram staining method

Christian Gram (1884)

Bordeaux mixture developed by

P.M.A. Millardet (1885)

Systemic fungicide discovery

Van Schmeling & Kulka (1966)

Coffee rust outbreak

Sri Lanka (1867) – caused by Hemileia vastatrix

Late blight of potato

Phytophthora infestans

Wart disease of potato

Synchytrium endobioticum

Club root of cauliflower

Plasmodiophora brassicae

White rust of crucifers

Albugo candida

Brown spot of rice

Helminthosporium oryzae

Downy mildew of bajra (pearl millet)

Sclerospora graminicola

Black rust of wheat

Puccinia graminis tritici

Loose smut of wheat

Internally seed-borne (Ustilago segetum tritici)

Powdery mildew control

Sulphur fungicide or Dinocap (Karathane)

Purple blotch of onion

Alternaria porri

Pineapple disease of sugarcane

Ceratocystis paradoxa

Moko disease of banana

Pseudomonas solanacearum

Bunchy top of banana

Banana Bunchy Top Virus (BBTV)

Papaya mosaic disease

Viral

Coffee rust

Hemileia vastatrix

Malformation of mango

Fusarium sp. (fungal factor)

Wart disease of potato (India)

Endemic to Darjeeling hills (W. Bengal)

Most plant viruses

ss-RNA (+) type (~78% of all plant viruses)

Largest virus family in plants

Potyviridae

Cauliflower mosaic virus (CaMV)

Contains dsDNA

Most common virus vectors

Aphids

Vector of potato leaf roll virus

Aphids

Mycoplasma sensitivity

Tetracycline

Spiroplasma

Helical, motile form of MLOs (Mycoplasma-like organisms)

Prions

Infectious protein particles with no nucleic acid

Cybrids

Contain nucleus of one and cytoplasm of both parents

Examples of prokaryotes

Bacteria, BGA, Mycoplasma, Phytoplasma

Ergot

Mycelial form is called Sclerotia

Ooze test

Used to detect bacteria

Bordeaux mixture

CuSO₄ + Ca(OH)₂; first fungicide

Carboxin (Vitavax)

Effective against smut diseases

Metalaxyl (Ridomil, Apron SD)

Effective against Oomycetes fungi

Sulphur fungicide / Dinocap

Controls powdery mildew

Chlorine

Suppresses downy mildew of pearl millet

Tetracycline

Antibiotic effective against MLOs

Peronosporales

Includes Phytophthora infestans (late blight) and Albugo candida (white rust)

Ustilaginales

Smut fungi

Basidiomycetes

Includes rust and smut fungi

Oomycetes

Water molds (e.g., Phytophthora, Pythium)

Vertical resistance

Major gene / qualitative / race-specific resistance

Pathogenesis

Chain of metabolic events causing disease

Pathogenicity

Ability of a pathogen to cause disease

Syndrome

Sum total of symptoms and signs

Blast disease reduction in rice

Through silicon application

Agar-agar source

Gelidium amansii (Red seaweed)

Bacteria used in biocontrol

Pseudomonas fluorescens

ELISA test

Used mainly for viral diseases

Downey mildew fungi

Belong to order Peronosporales

Oospores in downy mildew

Resting spores – cause primary infection

Uredospores in rust fungi

Repeating spores (dikaryotic n+n)

Sexual spores in downy mildew

Oospores (2n)

Most poisonous mushroom

Amanita phalloides

Agrobacterium-mediated transformation

Effective only in dicots

Downy mildew of Bajra – primary infection

Through oospores (resting spores)