Detection of TYLCV in Ten Genotypes of Tomato (Solanum spp L.) using Serological and Molecular Techniques in a Coastal Savanna Zone of Ghana

Abstract

Use of resistant varieties is a proven way of controlling the tomato yellow leaf curl virus (TYLCV), which causes a devastating disease of tomato in tropical and warm temperate regions, resulting in significant yield losses. However, breeding for resistant varieties is slow due to lack of effective methods of virus detection that will lead to efficient selection of desired varieties. A study was conducted to evaluate the susceptibility or otherwise of ten tomato genotypes to TYLCV under field conditions. The ten (10) tomato genotypes were planted in the field and left to natural infection by whitefly vectors. Leaf samples were collected from symptomatic as well as asymptomatic plants at five weeks after transplanting (5WAT) for analysis by serological and nucleic acid-based techniques. Triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA) detected TYLCV in five out of ten genotypes while polymerase chain reaction using six primers (virus-specific and degenerate) detected the virus in eight out of ten genotypes. The polymerase chain reaction (PCR) technique detected the virus in three samples that tested negative to TAS-ELISA, implying its enhanced sensitivity. A correlation of symptom expression in the field to the presence of TYLCV in test samples led to an effective and unbiased selection of tolerant/resistant genotypes which can be used in further breeding programmes. The study highlights the need for a combination of two or more detection techniques in breeding to enhance the efficiency of selection of TYLC-resistant lines.

Keywords: Tomato yellow leaf curl virus, enzyme-linked immunosorbent assay, polymerase chain reaction, genotypes, resistant varieties, Solanum lycopersicon.