Mechanical transmissibility effect of Telfairia mosaic virus (TEMV) and Cucumber Mosaic Virus (CMV) on growth and nutritional composition of Telfairia occidentalis

Abstract

Screenhouse potted experiment was conducted to determine the mechanical transmissibility effect of Telfairia mosaic virus (TeMV) and  Cucumber mosaic virus (CMV) on the growth and nutritional composition of two Telfairia occidentalis cultivars. The experiment was a  complete randomized design (CRD) with 6 treatments each replicated 5 times. Virus inoculation was done mechanically through sap  extracted by homogenization from infected leaf tissues. Weekly data from 4 - 8 weeks after germination was collected on plant height,  number of leaves per plant and number of leaves showing viral symptoms. The nutritional composition of leaf samples was determined  using Association of Official Analytical Chemists (AOAC) 1990 methods. All collected data were subjected to analysis of variance and  treatment means separated using the New Duncan Multiple Range Test at 5 % level of probability. The mechanical transmissibility of the  viruses was successful with inoculated plants manifesting characteristic virus symptoms. Virus severity was significantly (P ≤ 0.05) highest  in Ugu-Ala cultivar inoculated with TeMV (17.3% - 31.5%). The tallest plants were Ugu-Elu cultivar inoculated with CMV (104.4 cm - 141.3cm) while Ugu-Ala cultivar inoculated with TeMV produced the lowest number of leaves (18.0 - 26.8). Nutritional composition study  revealed that TeMV and CMV caused significant reductions in dry matter, ash, crude protein, crude fat and crude fiber contents compared  to healthy controls. This stresses the need for management of viruses of T. occidentalis by use of resistant cultivars to improve  production and enhance nutritional status.