Detection of Weligama Coconut Leaf Wilt Disease Phytoplasma by Real-Time Polymerase Chain Reaction

  • H.T.R. Wijesekara
  • S.A.C.N. Perera
  • D. Bandupriya
  • M.K. Meegahakumbura
  • Lalith Perera
Keywords: Coconut, Weligama Coconut Leaf Wilt Disease, Phytoplasma Detection, qPCR

Abstract

Weligama Coconut Leaf Wilt Disease (WCLWD) is a non-lethal, but debilitating phytoplasma disease found in coconut palms in Sri Lanka which is confined to the Southern Province of the country, well-away from the major coconut growing area. If it spreads to the major coconut growing area, it might severely damage the coconut industry in Sri Lanka. Government commenced a disease control program to eradicate the disease and, more importantly to prevent spreading of the disease to major coconut growing areas. The major constraint in this program is the lack of an accurate and reliable method for identifying affected palms. Visual symptoms are used to identify the affected palms for removal, yet growers are not always convinced of the method of resisting palm removal. This poses a serious threat to the implementation of the disease control program. Although a Nested-PCR-based disease diagnosis was established earlier, the detection rate and reliability need further improvements. Therefore, an urgent necessity for a more reliable disease detection method has arisen. In the current study, a Real-Time Polymerase Chain Reaction (qPCR) powered by a pair of primers and a probe designed from the published partial sequences of the WCLWD phytoplasma was validated with 202 coconut samples and a detection rate of above 95% was achieved. This newly established detection system was highly reliable and a way forward for controlling the WCLWD disease in Sri Lanka.

References

Ahrens, U. and Seemuller, E. 1992. Detection of DNA of plant pathogenic mycoplasma like organisms by a polymerase chain reaction which amplifies sequence of the 16S rRNA gene. Phytopath 82, 828 – 832.

Constable, F.E., Gibb, K.S. and Symons, R.H. 2003. Seasonal distribution of phytoplasmas in Australian grapevines. Plant Pathol.
52: 267 – 276.

Nainanayaka, N.P.A.D. and Ranasinghe, C.S. 2013. Physiological/Biochemical effects of WCLWD on palm and its production. In: Weligama Coconut Leaf Wilt Disease. Six years after. Eds. H.P.M. Gunasena, H.A.J. Gunathilaka, L.C.P. Fernando, J.M.D.T. Everard and P.A.H.N. Appuhamy. Coconut Research Institute of Sri Lanka, Lunuwila, Sri Lanka. pp. 31-47.

Perera, L., Russell, J.R., Provan, J. and Powell, W. 1999. Identification and characterization of microsatellites in coconut (Cocos nucifera L.) and analysis of coconut population in Sri Lanka. Molecular Ecology 8: 344 – 346.

Perera, L., Meegahakumbura, M.K., Wijesekara, H.T.R., Fernando, W.B.S. and Dickinson, M.J. 2012. A phytoplasma is associated with the Weligama coconut leaf wilt disease in Sri Lanka. J. Pl. Pathol. 94(1): 205 – 209.

Ramjegathesh, R. Karthikeyan, G., Rajendran, L., Johnson, I., Raguchander, T. and Samiyappan, R. 2012. Root wilt disease of coconut palms in South Asia – An Overview. Archives of Phytopathology and Plant Protection. 45(20): 2485-2493.

Sambrook, J., Fritsch, E. and Maniatis, T. 1982. Molecular Cloning. A Laboratory Manual. Cold Spring Harbor laboratory press, NY, USA. 6.3 – 6.6 and 14.34 – 14.5.

Wijesekara, H.T.R., Perera, L., Wickramananda, I.W., Herath, I., Meegahakumbura, M.K., Fernando, W.B.S. and De Silva, P.H.P.R. 2008. Preliminary investigation on Weligama Coconut Leaf Wilt Disease: A new disease in Southern Sri Lanka. In: Proc. Second Symp. Plantation Crop Res. – Export competitiveness through quality improvements. Eds. N.A.D.P. Nainanayake and J.M.D.T. Everard. Coconut Research Institute, Lunuwila, Sri Lanka.
pp. 336 – 341.

Wijesekara, H.T.R. and Fernando, L.C.P. 2013. Symptoms and Etiology of Weligama coconut leaf wilt disease. In: Weligama Coconut Leaf Wilt Disease. Six years after. Eds. H.P.M. Gunasena, H.A.J. Gunathilaka, L.C.P. Fernando, J.M.D.T. Everard and P.A.H.N. Appuhamy. Coconut Research Institute of Sri Lanka, Lunuwila, Sri Lanka. pp. 18 – 25.

Wijesekara, H.T.R., Perera, A.A.F.L.K., Meegahakumbura, M.G.M.K., Dassanayaka, E.M. and Ranasinghe, C. (2013). Serological and Molecular Techniques. In: Weligama Coconut Leaf Wilt Disease. Six years after. Eds. H.P.M. Gunasena, H.A.J. Gunathilaka, L.C.P. Fernando, J.M.D.T. Everard and P.A.H.N. Appuhamy. Coconut Research Institute of Sri Lanka, Lunuwila, Sri Lanka. pp. 56 – 62.
Published
2020-11-21
How to Cite
Wijesekara, H., Perera, S., Bandupriya, D., Meegahakumbura, M., & Perera, L. (2020). Detection of Weligama Coconut Leaf Wilt Disease Phytoplasma by Real-Time Polymerase Chain Reaction. CORD, 36, 1-5. https://doi.org/10.37833/cord.v36i.425
Section
Articles