Se ha denunciado esta presentación.
Utilizamos tu perfil de LinkedIn y tus datos de actividad para personalizar los anuncios y mostrarte publicidad más relevante. Puedes cambiar tus preferencias de publicidad en cualquier momento.
MIC 319
FUNDAMENTALS
OF AGRICULTURAL
MICROBIOLOGY

CHAPTER 3
PLANT DISEASE DEVELOPMENT
BY
SITI NORAZURA JAMAL (MISS AZURA)...
OBJECTIVE
Be familiar with disease triangle
Clarify the factors for successful
disease development
Identify stages in d...
Outline
 Disease Triangle
 Factors for successful disease
development
1) Properties of pathogen
2) Properties of host
3)...
Disease
Triangle
Factors for successful disease
development
Disease Triangle

Three important components of
plant disease :
 Susceptible host
 Virulent pathogen
 Favorable enviro...
Disease Triangle
Factors for
successful
disease
development
1) Properties of Pathogen

Level of virulence
Adaptability
Dispersal efficiency
Survival efficiency
Reproductive fitn...
2) Properties of Host

Susceptibility
Growth stage & form
Population density &
structure
General health
3) Properties of Environment

Temperature
Rainfall / Dew
Leaf wetness period
Soil properties
Wind
Stages in
Disease
Development
Stages in Disease Development

1)Inoculation
2)Penetration
3)Infection
4)Growth and Reproduction
5)Dissemination of Pathog...
1) Inoculation

Inoculation : The arrival of pathogen
on the host

Inoculum
 The pathogen (s) that land on the host or
...
Types of inoculum

Primary inoculum
 An inoculum that survives the dormant period &
caused the first infections

Primar...
Landing or Arrival of inoculum
 Most is carried by wind, water, insects
 Only a small number actually lands on
susceptib...
2) Penetration

The initial invasion of a host by a
pathogen:
1. Direct Penetration
2. Penetration Through Natural
Openin...
Direct penetration
1)Direct Penetration
 Direct with haustoria
 Direct, subcuticular only
 Direct intercellular mycelli...
Direct penetration
The most common type of
penetration by fungi and nematodes
and the only type by parasitic plants
Fung...
Direct penetration
The penetration is through
mechanical force and softening of the
cell walls by an enzyme
Most fungi f...
Direct penetration
The peg grows into a fine hyphae
then reaches a normal diameter once
it is inside the cell
As in the ...
Direct With Haustoria
Direct, subcuticular only
Direct, Intercellular Mycelium
Direct, Intercellular Mycelium with
Haustoria
Direct with appressorium (A),
penetration peg (PP) & intracellular
mycelium (IM)
2)Penetration Through Natural
Openings
Stomata
Lenticels (opening on fruits,
stems and tubers –filled with
loosely conne...
3) Penetration Through Wounds
Through various types of wounds
Natural cracks between main and
lateral roots
Openings ma...
3) Infection

Establishment of pathogen with
vulnerable cells or tissues of the
host and obtain the nutrients
from them
...
Incubation period : The time interval
between inoculation and the
appearance of disease symptoms
Latent infection : The ...
4) Growth and Reproduction

The pathogen will grow and multiply
within the infected host.
Fungi – spores
Viruses – repl...
5) Dissemination of Pathogen
 Pathogens are disseminated by several
ways:
 By air
 While airborne – spores touch wet
su...
 By water
 Pathogens in the soil – dissemination by
rain / irrigation water that moves on the
surface / through soil
 B...
 By Seed and Transplanting process
 Transported to other fields
 Are sold and transported to other areas
 By human
 T...
plant disease development
Próxima SlideShare
Cargando en…5
×

plant disease development

22.491 visualizaciones

Publicado el

Publicado en: Tecnología, Salud y medicina
  • Subject: Prayer for your support. Sir/Madam, We are pleased to introduce ourselves as an NGO in the district of Dhubri and this Non Governmental Organization was established in 1997 by a few educated youths with a view to undertake awareness, training, Socio-economic development of all sections of people of this economically backward region of Assam and registered under the Societies Registration Act,XXI of 1860.(Regd. No.RS/DBR/250/A/106 of 1997-98) on 1998. We have started this CLINIC with an aim & objective to provide services of farming related problems faced by the farmers of this region.. Your valuable suggestion and co-operation is highly solicited for smooth running of the Plant Health Clinic. Yours faithfully (MOHAMMEDUL HAQUE,B.Sc.Agril.) General Secretary NE PLANT HEALTH CLINIC ( An Unit of Chilarai Krishi Bikash Samity) A.K.Azad Road,Dhubri-783301,Assam Ph-9864568410/03662234007/e-mail: ckbs115@gmail.com/website:www.ckbs.vpweb.in
       Responder 
    ¿Estás seguro?    No
    Tu mensaje aparecerá aquí
  • good information especially on disease triangle model a great help indeed to my delivery of plant pathology concepts
       Responder 
    ¿Estás seguro?    No
    Tu mensaje aparecerá aquí

plant disease development

  1. 1. MIC 319 FUNDAMENTALS OF AGRICULTURAL MICROBIOLOGY CHAPTER 3 PLANT DISEASE DEVELOPMENT BY SITI NORAZURA JAMAL (MISS AZURA) 03 006/ 06 483 2132 norazura6775@ns.uitm.edu.my
  2. 2. OBJECTIVE Be familiar with disease triangle Clarify the factors for successful disease development Identify stages in disease development
  3. 3. Outline  Disease Triangle  Factors for successful disease development 1) Properties of pathogen 2) Properties of host 3) Properties of environment  Stages in disease development 1) 2) 3) 4) 5) Inoculation Penetration Infection Growth and Reproduction Dissemination
  4. 4. Disease Triangle
  5. 5. Factors for successful disease development
  6. 6. Disease Triangle Three important components of plant disease :  Susceptible host  Virulent pathogen  Favorable environment For disease to occur all three of these must be present.
  7. 7. Disease Triangle
  8. 8. Factors for successful disease development
  9. 9. 1) Properties of Pathogen Level of virulence Adaptability Dispersal efficiency Survival efficiency Reproductive fitness
  10. 10. 2) Properties of Host Susceptibility Growth stage & form Population density & structure General health
  11. 11. 3) Properties of Environment Temperature Rainfall / Dew Leaf wetness period Soil properties Wind
  12. 12. Stages in Disease Development
  13. 13. Stages in Disease Development 1)Inoculation 2)Penetration 3)Infection 4)Growth and Reproduction 5)Dissemination of Pathogen
  14. 14. 1) Inoculation Inoculation : The arrival of pathogen on the host Inoculum  The pathogen (s) that land on the host or  Any part of the pathogen that can initiate infection
  15. 15. Types of inoculum Primary inoculum  An inoculum that survives the dormant period & caused the first infections Primary infections  Infection caused by primary inoculum Secondary inoculum  An inoculum produced from primary infections Secondary infections  Infection caused by secondary inoculum
  16. 16. Landing or Arrival of inoculum  Most is carried by wind, water, insects  Only a small number actually lands on susceptible plants  Vector born pathogens are much more efficient since the vectors have an attraction for plants  E.g:     Germination of spores and seeds (fungus) Hatching of nematode eggs Attachment of Pathogen to Host (virus and bacteria) Recognition Between Host and Pathogen (Pathogen recognize the host)
  17. 17. 2) Penetration The initial invasion of a host by a pathogen: 1. Direct Penetration 2. Penetration Through Natural Openings 3. Penetration Through Wounds
  18. 18. Direct penetration 1)Direct Penetration  Direct with haustoria  Direct, subcuticular only  Direct intercellular mycellium  Direct, intercellular mycellium with haustoria  Direct with appressorium (A), penetration peg (PP) and intracellular mycelium (IM)
  19. 19. Direct penetration The most common type of penetration by fungi and nematodes and the only type by parasitic plants Fungi use a fine hyphae produced by a spore or mycelium or penetration peg produced by an appressorium This is formed at the point of contact with the host
  20. 20. Direct penetration The penetration is through mechanical force and softening of the cell walls by an enzyme Most fungi form an appressorium at the end of the germ tube Then a penetration peg emerges from the flat surface of the appressorium and pierces the cuticle and cell wall
  21. 21. Direct penetration The peg grows into a fine hyphae then reaches a normal diameter once it is inside the cell As in the case of apple scab, the fungus penetrates only the cuticle and stays between the cuticle and the cell wall Parasitic plants also penetrate the same way
  22. 22. Direct With Haustoria
  23. 23. Direct, subcuticular only
  24. 24. Direct, Intercellular Mycelium
  25. 25. Direct, Intercellular Mycelium with Haustoria
  26. 26. Direct with appressorium (A), penetration peg (PP) & intracellular mycelium (IM)
  27. 27. 2)Penetration Through Natural Openings Stomata Lenticels (opening on fruits, stems and tubers –filled with loosely connected cells – allow the passage of air) Hydathodes (permanently open pores at the margins and tips of leaves)
  28. 28. 3) Penetration Through Wounds Through various types of wounds Natural cracks between main and lateral roots Openings made by fungus
  29. 29. 3) Infection Establishment of pathogen with vulnerable cells or tissues of the host and obtain the nutrients from them Successful infection will produce symptoms
  30. 30. Incubation period : The time interval between inoculation and the appearance of disease symptoms Latent infection : The state in which a host is infected with a pathogen but does not show any symptoms
  31. 31. 4) Growth and Reproduction The pathogen will grow and multiply within the infected host. Fungi – spores Viruses – replicated by the cell Nematodes – reproduce by means of eggs 4. GROWTH & REPRODUCTION
  32. 32. 5) Dissemination of Pathogen  Pathogens are disseminated by several ways:  By air  While airborne – spores touch wet surfaces – get trapped – air movement stops / rains – washed out  From the air – brought down by rain drops  Winds also helps spreading by blowing away rain splash droplets containing pathogens
  33. 33.  By water  Pathogens in the soil – dissemination by rain / irrigation water that moves on the surface / through soil  By Insects, Nematodes & other Vectors  Transmitted by insects during feeding, movement from plant to plant  Nematodes can also transmit virus internally
  34. 34.  By Seed and Transplanting process  Transported to other fields  Are sold and transported to other areas  By human  Through handling of diseased and healthy plants  Tools (pruning shears)  Transporting contaminated soil on their feet / equipment  Contaminated container  Using infected seed / nursery stock

×