Detection of Cassava Mosaic Begomoviruses : A Part from the Book Chapter : Identifying New Species of Cassava Mosaic Begomovirus and Ageratum Leaf Curl Cameroon Virus on Pepper (Capsicum annuum L.) in Togo

Cassava leaves crops in green, tropical tree plant cassava plant

Foliar Sampling and DNA Extraction

Foliar samples from pepper plants intercropped with cassava showing typical symptoms of viral diseases (mosaic, distortion, leaf curling, yellowing and deformation) were collected through the five economic regions of Togo.

Total DNA was extracted from collected leaves using the DNA mini preparation method.

PCR Diagnosis

Detection of cassava mosaic begomoviruses (CMBs) in samples was performed by PCR amplification using three sets of specific primers targeting the coat protein (Table 1): JSP001/JSP002, JSP001/JSP003 and JSP012/JSP013 allow to identify respectively African cassava mosaic virus (ACMV), East African cassava mosaic virus (EACMV) and Indian cassava mosaic virus (ICMV). Another PCR was performed using begomoviruses coat protein-specific primers AC1048/AV494 to identify other begomoviruses apart from CMBs. PCR tests were done in the thermocycler “Mastercycle gradients Eppendorf (Hamburg, Germany). All PCR reactions were prepared in a 25 µl reaction mixture containing: template DNA 2 µl, dNTPs 0.5 µl (200 µM), primers 1.25 µl (each), Taq polymerase 0.16 µl (0.8 U), reaction buffer 2.5 µl (1X), MgCl2 2.5 µl (2.5 mM), BSA 0.5 µL (0.4 µg/µL), and Sterile water 14.34 µl.

Author(s) Details:

Kodjovi Atassé Dansou Kodjo
Laboratory of Plant Virology and Biotechnology (LVBV), Ecole Supérieure d’Agronomie (ESA), University of Lome, Lomé, Togo abd Laboratory of Agroecology, Ecophysiology and Integrative Biology (AEB), Unit EDYSAN FRE 3498 CNRS/University of Picardie Jules Verne, Amiens, France.

Assion Sétu Mivedor
Laboratory of Plant Virology and Biotechnology (LVBV), Ecole Supérieure d’Agronomie (ESA), University of Lome, Lomé, Togo.

Kossikouma Djodji Adjata
Laboratory of Plant Virology and Biotechnology (LVBV), Ecole Supérieure d’Agronomie (ESA), University of Lome, Lomé, Togo.

Jérôme Duclercq
Laboratory of Agroecology, Ecophysiology and Integrative Biology (AEB), Unit EDYSAN FRE 3498 CNRS/University of Picardie Jules Verne, Amiens, France.

Yawovi Mawuena Dieudonné Gumedzoe
Laboratory of Plant Virology and Biotechnology (LVBV), Ecole Supérieure d’Agronomie (ESA), University of Lome, Lomé, Togo.


Also See : An Overview of Zerumbone: Its Pharmacological Properties, Biosynthesis, Bioavailability, and Toxicological Effects


Recent Global Research Developments in Effects of Cassava Mosaic Begomovirus on Pepper in Togo

Interspecies Recombination and CMB Macroevolution:

  • A study by Crespo-Bellido et al. investigated the macroevolution of CMBs. These viruses significantly impact crop production and threaten food security worldwide. The emergence of new CMB genotypes is facilitated by high mutation rates and the propensity to recombine.
  • Homologous recombination, especially interspecies recombination, plays a crucial role in the emergence of novel CMB genotypes. Cassava, a staple food crop in Africa and an important industrial crop in Asia, is severely affected by CMB-induced cassava mosaic disease (CMD).
  • Recombination significantly impacts the CMB phylogeny and drives speciation within the CMD species complex [1].

Cassava Mosaic Disease and Pepper Intercropping:

  • Cassava mosaic disease, caused by whitefly-transmitted begomoviruses, poses a major threat to cassava production. Interestingly, cassava can be intercropped with other plants, including pepper (Capsicum annuum L.) [2].

West African Tomato-Infecting Begomoviruses (WATIBs):

  • Tomato and pepper plants with leaf curling were found to contain isolates of new begomoviruses known as WATIBs. These viruses, along with new alphasatellites and betasatellites, impact tomato and pepper crops [3].

Whitefly Transmission and Global Impact:

  • The whitefly Bemisia tabaci is a globally invasive species responsible for transmitting more than 320 plant viruses, including begomoviruses. These viruses cause economic damage to agroecosystems [4].

References

  1. Crespo-Bellido, A., Hoyer, J. S., Dubey, D., Jeannot, R. B., & Duffy, S. (2021). Interspecies recombination has driven the macroevolution of cassava mosaic begomoviruses. Journal of Virology, 95(17), 10-1128.
  2. Dansou-Kodjo, K. , Mivedor, A. , Adjata, K. , Duclercq, J. and Gumedzoe, Y. (2019) Occurrence of Cassava Mosaic Begomovirus New Species and Ageratum Leaf Curl Cameroon Virus on Pepper (Capsicum annuum L.) in Togo. Agricultural Sciences, 10, 671-682. doi: 10.4236/as.2019.105052.
  3. Leke, W.N., Mignouna, D.B., Brown, J.K. et al. Begomovirus disease complex: emerging threat to vegetable production systems of West and Central Africa. Agric & Food Secur 4, 1 (2015). https://doi.org/10.1186/s40066-014-0020-2
  4. Idrees, M.A., Abbas, A., Saddam, B. et al. A comprehensive review: persistence, circulative transmission of begomovirus by whitefly vectors. Int J Trop Insect Sci 44, 405–417 (2024). https://doi.org/10.1007/s42690-024-01170-3

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