Principles of plant infection

PRINCIPLES OF PLANT INFECTION

DR. RAJBIR SINGH Assistant Professor

Department of Plant Pathology Gochar Mahavidyalaya, Rampur Maniharan, Saharanpur (UP), India Affiliated to Ch. Charan Singh University, Meerut (UP), India

Email: rajbir25805@yahoo.com, rajbirsingh2810@gmail.com

Cell No. 91-9456613374

(A). Penetration - “Entry of pathogen in the host is called penetration”

(i). Direct penetration fungi, nematodes & parasitic pls.

Mechanic forces & enzymatic softening

By appressorium in fungi

3. Haustorium

2. Appresorium

(ii). Through woundsAll bacteria, most fungi, some virus & viroidEnter through wounds

Virus, MLO, RLO enter through wounds made by vector

iii). Through natural opening

(a). Stomata

Many fungi & bacteria enter through stomata

Penetration through Stomata

(b). Hydathodes

are more or less permanently open pores at

the end on the tip of leaves

Bacteria enter through hydathodes

(c). Lenticels

Are openings on fruits, stem, tubers that

are filled with loosely connected cells to

allow passage of air

Few fungi and bacteria enter through lenticels

(B). Infection

“The establishment of a pathogen with in a host plant”

“Infection is the process by which pathogen

establish contact with susceptible cell or

tissues of the host and procure nutrients

from them”

(C). Invasion

“ The spread of the pathogen with in the host”

Fungi spread - Intercellular, intercellular

Bacteria - Intercellular, intercellular

Virus, virods, MLO, phytoplasma & RLO

By moving from cell to cell interacellularly

(D). Dissemination or Dispersal of Pathogen

(A). Autonomous Dissemination

(1). By Soil

(2). By Seeds

(3). By Plant and Plant Parts

(B). Passive Dissemination

(1). By Air

(2). By Water

(3). By Vectors

(4). By Humans

Thank You