Blackgram leaf crinkle and curl disease

Fundamentals of Plant Pathology

1. CANDIDATUS PHYTOPLASMA: CHARACTERS, CLASSIFICATION AND SYMPTOMS COLLEGE OF AGRICULTURAL TECHNOLOGY (Affiliated to Tamil Nadu Agricultural University, Coimbatore-3) Kullapuram (Po), ViaVaigai Dam, Theni-625 562 STUDENT SARASWATHI S DEEPAN S COURSE TEACHER Dr. PARTHASARATHY.S Asst. Professor (Plant Pathology)

2. CHARACTERS : Free living, parasitic and saprophytic and reproduces by budding and binary fussion . Cell contain cytoplasm, ribosome and nucleic acid devoid of nuclear membrane . Generally present in the sap of a small number of phloem sieve tubes.

3. The candidatus phytoplasma is obligate symbionts of plant and insects. Usually resistant to antibiotics like penicillin, cephaloridin Which acts on cell wall but they are sensitive to tetracycline. Unicellular, gram positive, non motile, highly pleomorphic and their size ranges from small, spherical bodies to tubular to filamentous branched structures.

4. SCIENTIFIC CLASSIFICATION: Domain: Bacteria Phylum: Firmicutes Class: Mollicutes Order: Acholeplasmatales Family: Acholeplasmataceae Genus: Candidatus Phytoplasma

5. SYMPTOMS Gradual yellowing of leaves. Shortening of internode . Greening or sterility of flowers. Decline and death of plants. Stunting of plants. Reduction in size of leaves.

6. Gingelly phyllody - Ca. Phytoplasma asteris Reduction in size of leaves. Shortening of internode . Conversion of floral parts into green leafy structures. Diseased plants become completely sterile. This disease is transmitted by leaf hopper

7. Gingelly phyllody - Ca. Phytoplasma asteris

8. Jasmine phyllody – Ca. Phytoplasma aurantifolia Leaves turn yellow and reduction of leaf size Floral parts are converted into leaf like structures This disease is transmitted by whitefly

9. Jasmine phyllody - Ca. Phytoplasma aurantifolia

10. Brinjal little leaf - Ca. P hytoplasma trifolii Diseased plants produce small, narrow, thin, sessile, soft, glabrous and pale green colour leaves in a shortened internode.The plants look bushy due to the stimulation of auxillary buds and are sterile.The disease transmitted by leaf hopper.

11. Brinjal little leaf - Ca. Phytoplasma trifolii

12. Sugarcane grassy shoot – Ca.Phytoplasma oryzae This disease is otherwise called yellowing disease or bushy disease . Profuse tillering and grassy appearance of the shoot are The main symptoms. Small grass like leaves and canes are thin with short internode. The vector is aphid.

13. Sugarcane grassy shoot – Ca.Phytoplasma oryzae

14. Coconut lethal yellowing – Ca.Phytoplasma palmae The first symptom is the drooping of pre- matured nuts of any size followed by blackening of inflorescence tip and all male flowers. Then the lower leaves exhibit yellowing which progress upward to the young one. Later the lower leaves die prematurely, turn brown and cling to the tree while the young one become yellow. This disease is transmitted by plant hoppers.

15. Coconut lethal yellowing - Ca. Phytoplasma palmae

16. Rice yellow dwarf - Ca. Phytoplasma oryzae Affected plants become dwarf with pale green or yellow narrow leaves and are sterile.

17. REFERENCE D . Alice and C . Jeyalakshmi “ PLANT PATHOLOGY” , 2011, A .E . Publication, Page No : 239-242

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