Global Advanced Research Journal of Agricultural Science (GARJAS) ISSN: 2315-5094
October 2014 Vol. 3(10): pp. 310-316
Copyright © 2014 Global Advanced Research Journals
Full Length Research Paper
Evaluation of the infection of cassava and Nicotiana benthamiana with cassava mosaic geminiviruses and their combinations for potential synergism
Thomas E. Njock
Department of Agronomic and Applied Molecular Sciences, Faculty of Agriculture and Veterinary Medicine, University of Buea, P.O. Box 63 Buea, Cameroon.
Accepted 01 October, 2014
Five test plants each of cassava and Nicotiana benthamiana were inoculated in vitro with 50 ng cassava mosaic geminivirus (CMG) deoxyribonucleic acid (DNA) of components A and B and their random combinations for strains African cassava mosaic-Cameroon virus (ACMV-CM), East African cassava mosaic Cameroon virus (EACMV-CM), East African cassava mosaic Uganda virus (EACMV-UG), Indian cassava mosaic virus (ICMV) and Sri Lankan cassava mosaic virus (SLCMV) were investigated for synergistic interactions by bombardment with gold particle-coated viral DNA using the biolistic particle delivery system giving a total of 80 plants. The plants were maintained in an insect-proof greenhouse and scored for infection one week post inoculation (wpi) for 8 weeks on a scale of 1-5. The experiment was replicated twice. Incidence of infection was higher on N. benthamiana than cassava plants. The highest infection was with ACMCV/ICMV (100 %) on N. benthamiana and this was not significant over ACMV-CM (98.8 %) and the positive control ACMV-CM/EACMV-CM (96.3 %). Thus the combination ACMV-CM/ICMV probably had a synergistic effect on N. benthamiana. On cassava, however, the highest infection was ACMV-CM/EACMV-CM (50 %) which was not significant over ACMV-CM/SLCMV (46.3 %). Similarly, viral effect was more severe on N. benthamiana than on cassava plants. The most severe effects were by SLCMV (2.81), SLCMV/EACMV-CM (2.42) and ACMV-CM (2.32). ACMV-CM/EACMV-CM had earlier been demonstrated on cassava to have a synergistic effect. This study demonstrated that the ACMV-CM/ICMV combination had a synergistic effect on N. benthamiana and thus a potential threat of significance in plant virus disease epidemiology and therefore subject to further investigation.
Keywords: cassava mosaic disease (CMD), cassava mosaic geminiviruses (CMGs), CMG combinations, synergism, cassava, N. benthamiana.