This document discusses nematode-virus transmission. It reports that nematodes of the order Dorylaimida were first found to transmit virus particles that infect grapevines. There are two main types of viruses transmitted: NEPO viruses, which are polyhedral shaped and 30nm in size and transmitted by Xiphinema and Longidorus nematodes; and NETU viruses, which are tubular, 180-210nm in size, and transmitted by Trichodorus and Paratrichodorus nematodes. The document also outlines the vector specificity of certain nematode species to different viruses, the steps involved in virus transmission, and examples of specific nematode-virus relationships that cause various plant diseases.

1. R. Mouniga
2018801401
Nematode- virus transmission

2. Hewitt, Raski and Goheen(1958)- first reported Nematode virus
interaction in grapevine
Normally Dorylaimids transmits the virus particles
Types of virus:
 NEPO (Nematode Emitted Polyhedral Virus)
 NETU (Nematode Emitted Tubular Virus)
(Cadman,1963)

3. NEPO Virus:
 Nematode transmitted Polyhedral virus
 Polyhedral- shape
 30 nm in size.
 Xiphinema and Longidorus
NETU Virus:
 Nematode Emitted Tubular virus
 Also called as TOBRA virus
 180-210 nm in size
 Trichodorus and Paratrichodorus

4. Vector specificity
 11 spp of xiphinema- 13 NEPO virus
 14 spp of Trichodorus- various strain of tobacco rattle and pea
early browning
Brown et al. (1995)

5. Steps involved in virus transmission:
1.Acquistion
2. Retention
3. Dissociation
4. Transmission
Taylor et al. (1970)

6. Example for NEPO virus transmission:
Nematode species Viral disease
X. americanum Tomato ring spot, Tobacco
ringspot
X. californicum Cherry leaf mottle
X. diversicaudatum Arabis mosaic virus
X. index Grape fan leaf
Longidorus elongatus Raspberry ringspot , Tomato
black ring
L. Leptocephalus, L.elongatus,
L.attenuatus
Docking disorder of sugarbeet

7. Example for NETU virus transmission
Nematode species Viral disease
Trichodorus viruliferous Tobacco rattle and Pea early
browning
T. similis Tobacco rattle
T. Cylindricous,T. primitus Pea early browning
Paratrichodorus minor Corky ringspot of potato
(Claver, 2018)

8. SYMPTOMS
Grape Fan Leaf Virus Tobacco rattle virus

9. Docking Disorder of sweet potato

10. Pea early yellow browning Tobacco rattle virus

11. Corky ringspot of potato sparing Tobacco yellow mosaic virus

12. Why not Tylenchids transmits the virus?
Chemical nature is differ from Dorylaimids
Stylet is small compared to Dorylaimids
Odontostylet is large in Dorylaimids

13. THANK YOU...........