This document is a report on clubroot disease of cabbage caused by the soil-borne pathogen Plasmodiophora brassicae. It discusses the distribution, history, economic impact, symptoms, disease cycle, pathogen, modes of spread, favorable conditions, and integrated disease management of clubroot. Clubroot causes gall formation on cabbage roots, restricting water uptake and causing wilting, stunting, and death. The pathogen survives in soil as resting spores for many years, infecting plants through zoospores that enter through wounds or root hairs. Management includes use of disease-free seedlings, crop rotation, and incorporating lime into soil.

1. Name : Anza Afzal Dar
Course Title : Diversity Of Plants
Course Code: BOT-101
Department : Zoology
UNIVERSITY OF
GUJRAT
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2. 20011514-055
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3. Content:
 Intoduction...............................4
 Distribution................................5
 History........................................6
 Economic Significance............8
 Symptoms..................................9
 Disease cycle............................12
 Pathogen....................................16
 Mode of Spread.........................18
 Disease Management...............20
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4. CLUBROOT OF
CABBAGE
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5. INTRODUCTION
Cabbage:
Cabbage is a member of
genus Brassica and
mustard family,
Cruciferaceae.
The sulphorane found in
cabbage may help to
protect from cancer.
Figure:
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6. DISTRIBUTION
 India,Nepal,China,West
Bengal,Canada,Bulgaria,Denmark and
Hongkong.
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7. HISTORY
 Historical reports of clubroot date back to the
13th century in Europe.
 In 19th century, a severe epidemic of clubroot
destroyed large proportions of the cabbage
crop in St. Petersburg.
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8. HISTORY
 The Russian scientist Mikhail
Woronin eventually identified the
cause of clubroot as a
“Plasmodiophorous organism”
in 1875, and gave it the name
Plasmodiophora brassicae.
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9. ECONOMIC SIGNIFICANCE
 Clubroot can be a reccurring problem, for
years because it is easily spread from plant to
plant.
 P. brassicae is able to infect 300 species of
cruciferous plants.
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10. SYMPTOMS
• Developing plants may not show any symptoms
but as the plants get older they will start to show
symptoms of chlorosis or yellowing.
• Wilting during hot days and stunted growth.
• The roots experience cell proliferation due to
increased auxin or growth hormone production.
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11. SYMPTOMS
 Gall formation occurs and restrict the
xylem tissue inhibiting efficient water
uptake by the plant.
 Galls appear like clubs or spindles on the
roots.
 The roots will rot and the plant will die
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12. CLUBROOT OFCABBAGE
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13.  In the spring, resting spores in the soil germinate
and produce zoospores and then these spores
swim and enter host plants through wounds or
root hairs.
 The plasmodium eventually divides and forms
secondary zoospores that are once again
released into the soil.
Disease Cycle of
Plasmodiophora brassicae
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14.  The secondary infection by the zoospores can
infect the first host or surrounding hosts.
 The secondary zoospores form a secondary
plasmodium that affects plant hormones to
cause swelling in root cells.
 These cells turn into galls or “ club “.
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15. Contd.
 The secondary plasmodium forms the
overwintering resting spores which
get released into the soil as the club
rot and disintegrate.
 These resting spores can live in soil
for upto 20 years while they wait for a
root tip to come in close proximity for
them to infect.
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17. P
ATHOGEN
 Obligate parasite.
 Plasmodium shaped body.
 Can survive in soil as resting spores for many
years.
 Produce primary and secondary zoospores.
Zoospores are biflagellate. 20011514-055
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18. MODE OFSPREAD
 Primary:Restingspores
 Secondary: Zoospores
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19. Resting spores: Zoospores:
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20. FAVOURABLE CONDITION
m
oist
 It prefers warmer temperature and
conditions.
 Soil temperature between 20 - 24°C.
 pH less than 6.5.
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21. INTEGRATED DISEASE
MANAGEMENT
 Seedlings can carry the pathogen so the use of
disease free seedlings is therefore very important.
to reduce the
 Remove the affected roots pathogen
population in the soil.
 Practice long term crop rotation with potato, tomato,
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22.  Incorporate lime into the field at the rate of
2.5t/ha two weeks before transplanting .
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