Early signs of infection in Cacao swollen shoot virus (CSSV) inoculated cocoa seeds and the discovery of the cotyledons of the resultant plants as rich sources of CSSV

Despite the huge efforts and funds expended to try and bring Cacao swollen shoot virus (CSSV) disease under control, the disease has remained largely intractable. Inspired by the need to inject newideas into the current breeding programmes for CSSV resistance, the interactions between cocoa and the virus in CSSV-infected plants from 3 days post inoculation (dpi) to about 30 dpi were studied using both microscopic and molecular methods. Cellular modifications such as nucleic acid-rich inclusion bodies, apoptosis, and the in situ localisation of the virus in novel tissues that is cotyledons and hypocotyl, were discerned by microscopic examinations. These cellular modifications were observed incotyledons of seedlings as young as 8 dpi. By validating these microscopic results using PCR it was also discovered that the cotyledons of the inoculated plants were virus-rich. CSSV was amplified or detected in total DNAs extracted from all 4 CSSV-isolates studied, and in some cases the detection was from as early as 3dpi plants. Compared to cocoa leaves, the traditional source from which CSSV or its DNA is usually extracted, the cotyledons were much easier to process and analyse. The significance ofthese findings to the CSSV-resistant breeding programmes, and to CSSV research in general is discussed

Cocoa swollen shoot virus in Ghana: A review of diagnostic procedures

A quick and more reliable diagnostic method has for a long time been identified as one input that will greatly enhance the control of the cocoa swollen shoot disease in Ghana. Many diagnostic procedures have beendeveloped for detecting the virus that causes the disease; yet, the detection of latent infections is still unpredictable. This paper reviews work done indiagnosing swollen shoot disease to develop a quicker, more reliable, and cost-effective method that could be applicable in programmes for controlling cocoa swollen shoot disease. Enzyme-linked immunosorbent assay(ELISA), virobacterial agglutination tests (VBA), and other biochemical analyses have been discussed as diagnostic tools that could be developed to effectively replace the use of visible symptom expressions as theonly method for field detection of the disease

Recent studies of mild strain cross-protection with cocoa swollen shoot virus

No Abstract. Journal of the Ghana Science Association Vol. 2 (2) 1999: pp.8-1

Recent studies of mild strain cross-protection with cocoa swollen shoot virus

No Abstract. Journal of the Ghana Association Vol. 2 (3) 1999: pp.5-1

The use cloned DNA probes for the detection and identification of cocoa swollen shoot virus (CSSV) 1A and CSSV Nsaba

No Abstract. Journal of the Ghana Association Vol. 2 (3) 1999: pp.102-10

Next generation sequencing elucidates cacao badnavirus diversity and reveals the existence of more than ten viral species

Cacao swollen shoot virus is a member of the family Caulimoviridae, genus Badnavirus and is naturally transmitted to Theobroma cacao (L.) by several mealybug species. CSSV populations in West African countries are highly variable and genetically structured into several different groups based on the diversity in the first part of ORF3 which encodes the movement protein. To unravel the extent of isolate diversity and address the problems of low titer and mixed viral sequences in samples, we used Illumina MiSeq and HiSeq technology. We were able to reconstruct de novo 20 new complete genomes from cacao samples collected in the Cocoa Research Institute of Ghana (CRIG) Museum and from the field samples collected in Côte d'Ivoire or Ghana. Based on the 20% threshold of nucleotide divergence in the reverse transcriptase/ribonuclease H (RT/RNase H) region which denotes species demarcation, we conclude to the existence of seven new species associated with the cacao swollen shoot disease. These new species along with the three already described leads to ten, the total number of the complex of viral species associated with the disease. A sample from Sri Lanka exhibiting similar leaf symptomology to West African CSSD-affected plants was also included in the study and the corresponding sequence represents the genome of a new virus named cacao bacilliform SriLanka virus (CBSLV). [Abstract copyright: Copyright © 2017. Published by Elsevier B.V.