Comparative Study of the Effect of Telfairia Mosaic Virus (TEMV) on the Growth Characteristics of Two Ecotypes of Telfairia occidentalis (Hooker Fil)

Abstract

The effect of Telfairia Mosaic Virus (TeMV) on the growth characteristics of two ecotypes of Telfairia occidentalis was investigated. Seeds of T. occidentalis obtained from Akparabong in Ikom Local Government Area of Cross River State were designated ecotype A and seeds from Eket in Eket Local Government Area of Akwa Ibom State were designated ecotype B. Infection of T. occidentalis by TeMV caused significant reductions (p<0.05) in leaf area, shoot height, leaf number, leaf fresh and dry weight, fresh and dry weight of shoot and root. Percentage difference values for the above parameters were 57.19, 40.10, 46.59, 25.0, 24.5, 31.65, 37.43, 30.78, 19.97, 37.01 and 21.94% for ecotype A and B in infected samples compared to healthy controls. The virus also induced (p<0.05) reductions in Relative Growth Rate (RGR), with percentage difference values for ecotype A and B ranging from 21.1-21.7, 17.5 and 28.2%, with values for Net Assimilation Rate (NAR) for ecotype A and B ranging from 22.1-39.3 and 20.5-34.4%, respectively and percentage difference values for Leaf Area Ratio (LAR) for ecotype A and B ranging from 13.9-26.0 and 15.0-25.3%, respectively. Telfairia mosaic virus infection caused significant (p<0.05) reductions in RGR, NAR and LAR in inoculated plants of ecotypes studied compared to the healthy controls with ecotype A being more susceptible to the effect of TeMV infections than ecotype B. The virus also reduced the quality of the vegetable. Since, the difference in plant growth between infected and healthy plants depend on infection, this explains the difference in growth and plant size. These reductions in plant growth characteristics induced by TeMV infection alter the metabolism and subsequently dry matter yield of T. occidentalis.