Disclaimer & Fair Use Statement
This website may contain copyrighted material, the use of which may not have been specifically authorised by the copyright owner. The content within this website is distributed without profit for research and educational purposes. This constitutes a 'fair use' of any such copyrighted material as provided for in section 107 of the US Copyright Law. You must obtain the express permission of the copyright owner if you wish to use any copyrighted material from this website.
This website may contain copyrighted material, the use of which may not have been specifically authorised by the copyright owner. The content within this website is distributed without profit for research and educational purposes. This constitutes a 'fair use' of any such copyrighted material as provided for in section 107 of the US Copyright Law. You must obtain the express permission of the copyright owner if you wish to use any copyrighted material from this website.
Cocadviroid Coconut cadang-cadang viroid (Cadang cadang disease)
General information
Coconut cadang-cadang disease is caused by a viroid. The name, ‘cadang-cadang’ is derived from ‘gadan-gadan’, which means ‘dead’ or ‘dying’ in the Filipino dialect.
CCCVd has caused premature decline and death of approximately 500,000 coconut palms in the Philippines [1, 2, 3]. The viroid is present in the husk, embryo of nuts and pollen.
Symptoms
- The disease progresses following three stages [1]:
- Early stage (first 2 to 4 years): Appearance of yellow leaf spots looking water-soaked in reflected light and translucent when viewed in transmitted light. The nuts become smaller and rounded with equatorial scarification.
- Medium stage (lasts around 2 years): More leaf spots appear with two thirds of the lower crown exhibiting bronzed-yellowish look. Nut and frond production ceases. The inflorescences become necrotic.
- Late stage (lasts around 5 years): The leaf spots merge. The number and size of fronds reduce with whole crown becoming yellowish/bronze. The leaflets become fragile and the palm dies off.
- Symptoms alone may not be conclusive for presence of disease as it can resemble physiological changes due to poor nutrition and water stress in the field, typhoon damage, and sterility. Frequent observations on the same palm are needed for symptomatic diagnosis. The time taken from first symptoms appearance to death of palms is usually around 8 to 16 years
- In some cases, an infected palm may not exhibit any visible symptoms and may seem harmless [4]. Hence, non-symptomatic palms could be kept for years not knowing the risk they may pose.
Symptoms on nuts
Diseased palms
Detection and Inspection
Symptoms alone are not reliable for disease diagnosis. Hence, in most cases viroid isolation and molecular screening is essential to confirm diagnosis. Molecular-level screening of plant tissue for CCCVd and its variants can be conducted using several methods including RT-PCR [6] and RT-LAMP [7].
Taxonomic information
Category - Virus
Family - Pospiviroidae
Genus - Cocadviroid
Species - Coconut cadang-cadang viroid
Names
Common Name - Cadang cadang disease
Scientific Name - Cocadviroid Coconut cadang-cadang viroid
Distribution
Coconut cadang-cadang disease was first reported in the central Philippines in the early 20th Century. From 1914 to 1931, it spread to northern and southern regions [3, 5].
Prevention and Control
Exclusion is the only method considered to be effective to control the spread of CCCVd. No resistant or tolerant coconut cultivars have been identified [8].
The import of germplasm material (seeds, pollen, tissue culture) must be subjected to thorough inspection.
References
- CABI ISC (2014). Datasheet report for coconut cadang-cadang viroid (cadang-cadang disease). Retrieved from http://www.cabi.org/isc/datasheet/13700.
- EPPO & CABI (n.d.). Coconut cadang-cadang viroid. Retrieved from www.eppo.int/QUARANTINE/data_sheets/virus/CCCVD
- Hanold, D. & Randles, J.W. (1991a). Coconut cadang-cadang disease and its viroid agent. Plant Dis, 75 (4), 330-335.
- Imperial, J.S., Bautista, R.M. & Randles, J.W. (1985). Transmission of the Coconut cadang-cadang viroid to six species of palm by inoculation with nucleic acid extracts. Plant Pathol, 34 (3), 391-401.
- Randles, J.W. & Rodriguez, M.J.B. (2003). Coconut cadang-cadang viroid. In A. Hadidi, R. Flores, J.W. Randles, & J.S. Semancik (eds.), Viroids (pp. 233-241). Collingwood, Australia: CSIRO Publishing.
- Vadamalai, G., Hanold, D., Rezaian, M.A. & Randles, J. (2006). Variants of Coconut cadang-cadang viroid isolated from an African oil palm (Elaies guineensis Jacq.) in Malaysia. Arch Virol, 151 (7),1447-56.
- Thanarajoo, S.S., Kong, L.L., Kadir, J., Lau, W.H. & Vadamalai, G. (2014). Detection of Coconut cadang-cadang viroid (CCCVd) in oil palm by Reverse Transcription Loop-Mediated Isothermal Amplification (RT-LAMP). J Virol Methods, 202,19-23.
- Randles, J.W. (1985). Coconut cadang-cadang viroid. In: K. Maramorosch & J.J. Jr. McKelvey (eds.), Subviral Pathogens of Plants and Animals (pp. 39-74). New York, USA: Academic Press.
Search by country
Search by region
Search by pest name
Search by pest category
© 2022 Cocopest. All rights reserved.