Taxanomy of Fungi: Plasmodiophora brassicae

 

SEM of Cabbage root infection

Taxonomical Hierarchy 

            Kingdom: Protzoa

            Phyllum:  Plasmodiophoromycota

            Class:      Plasmodiophoromycetes

            Order:     Plasmodiophorales

            Family:    Plasmodiophoraceae

            Genus:    Plasmodiophora

                                        

 Characteristics of Phyllum Plasmodiophoramycota:

1. Nutrition - absorptive nutrition

2. Vegetative stage produces naked unicellular plasmodium

3. Asexual Reproduction through motile/plano Zoospores 

4. Tubular Mitochondrial Crystae is present

5. Cruciform type of nuclear division.

6. Alternation of generation is observed => a distinct akaryotic phase consists of 2 types of Plasmodia

7. Isogamous type of sexual reproduction

8. Resting spores formed are present in the host cell

9. No frutification observed.

Club Root of Cabbage:

Club of Cabbage

Causative organism : Plasmodiophora brassicae

Distribution : Worldwide

    Club root of Cabbage is caused by the fungus Plasmodiophora brassicae . The major factor that favours this disease is low pH (acidic) of soil, which is caused by formation of humic acid . This is formed when there is heavy rainfall accompanied by the decomposition of fallen leaves of deciduous trees which leads to humus ( humic acid) production.

Management:

  1. Elevation of soil pH by applying Gypsum, Limestone, other alkaline substances.

  2. In severe cases avoid cultivation of the crop for 5- 10 years .

Life cycle of Plasmodiophora brassicae