The host range and vector species of viruses from Cola chlamydantha K. Schum., Adansonia digitata L. and Theobroma cacao L

Abstract

Sterculiaceae and Bombacaceae were tested for susceptibility to three virus isolates from naturally infected Cola chlamydantha trees and three from Adansonia digitata trees in Ghana. Seven species of Pseudococcidae were tested as vectors of the six isolates. These studies indicate that the Cola isolates should be classified with cocoa swollen shoot virus and those from Adansonia with cocoa mottle leaf virus.

Geographical Distribution of Cacao swollen shoot virus Molecular Variability in Côte d'Ivoire

“…Several experiments suggest that indigenous trees such as C. chlamydantha, C. gigantea. Ceiba pentandra, or A. digitata were the original hosts of swollen shoot virus and that the spread to cocoa occurred after the crop was introduced to West Africa at the end of the 19th century (14,24,25,30). In particular, group D, which is only present in the outbreaks of the center-west region, might indicate the possibility of spontaneous emergence of the disease in Côte d'Ivoire from reservoir plants, some of which are used as shade plants in Ivorian cocoa plantations.…”

“…Since then, and up to the discovery of outbreak in Bouaflé and Sinfra in 2003 (12), research on swollen shoot disease had been discontinued, because no agriculture service reports mentioned any cases over that long period. In addition, some indigenous reservoir plants of the same family or of families close to that of the cocoa tree, from the order of the Tiliales, displaying or not displaying symptoms similar to those caused by CSSV, naturally harbor a virus (14,24,33) which might lie at the origin of the disease in West Africa. Indeed, the disease can be experimentally transmitted from the species Ceiba pentandra, Cola chlamydantha, C. gigantea, and Adansiona digitata to cocoa seedlings by mealybugs that are vectors of CSSV (25).…”

Detection and Comparison of some Ghanaian Isolates of Cacao Swollen Shoot Virus (CSSV) by Enzyme‐Linked Immunosorbent Assay (ELISA) and Immunoelectron Microscopy (IEM) Using an Antiserum to CSSV Strain 1A

“…The failure of cross protection between strain 1A and the Kpeve isolate (POSNETTE 1947, CROWDY andPOSNETTE 1947), and between strain lA and the AD isolates (originating from naturally infected Adansoma digitata, baobab) (ATTAFUAH and TINSLEY 1958), also indicates some differences of these isolates from strain lA. The Kpeve and the AD isolates are transmitted by Planococcoides njalensis (Laing) which also transmits strain 1 A, but they are not transmitted by Ferrisiana virgata (Cockerell) although this vector transmits strain lA (POSNETTE 1947, and 1950, ATTAFUAH and TINSLEY 1958, DALE 1958, LEGG and BONNEY 1967.…”

“…The Kpeve and AD isolates further differ from strain IA by the absence of stem swellings and the induction of characteristic leaf symptoms in infected cacao plants. Based on the leaf symptoms and on other characters, the Kpeve and AD isolates have been described as a distinct cacao mottle-leaf virus (POSNETTE 1947, ATTAFUAH and DALE 1957, ATTAFUAH and TINSLEY 1958, THRESH and TINSLEY 1959, LEGG and BONNEY 1967.…”

“…More than 60 isolates of CSSV have been described (DALE 1962), mainly on the basis of symptomatology (POSNETTE 1947, ATTAFUAH and, host range WHARTON 1958, LEGG andBONNEY 1967), and vector specificity (POSNETTE 1950, LEGG andBONNEY 1967). It is therefore important to determine the range of isolates which can be detected with the antiserum to severe stram lA.…”