The first report of Tomato apical stunt viroid (TASVd) and Potato spindle tuber viroid (PSTVd) in tomatoes in Ghana

2013

english

Tomato plants (Solanum lycopersicum) with symptoms of stunted growth, leaf epinasy and necrosis of leaf veins and stems, were observed in Mali and Ghana in 2011 and found to be infected with Columnea latent viroid (CLVd). Surveys conducted in Ghana in 2012 revealed these CLVd-associated symptoms (locally referred to as ‘rasta’) in numerous fields in Agogo, Akomadan, Toubodan and Tonoso at incidences ranging from 0-15%. To test for CLVd, representative symptomatic leaf samples were applied onto Agdia absorption strips, total RNA extracted and RT-PCR performed with CLVd-specific primers. Results of these tests were negative; however, a virus-like agent was transmitted to tomato seedlings following mechanical-inoculation. In RT-PCR tests, amplification of the expected size fragment was directed by primers specific for Tomato apical stunt viroid (TASVd; 20% of plants) and Potato spindle tuber viroid (PSTVd; 80% of plants). The sequences of these putative TASVd and PSTVd fragments were 96% identical with those of TASVd isolates from the USA and Senegal, and PSTVd isolates from Western Australia and the U.K., respectively. In host range studies, the Ghana TASVd and PSTVd isolates only induced symptoms in tomato plants, although symptomless infections were detected in some species. This is the first report of TASVd and PTSVd in Ghana and, similar to CLVd, they may have been introduced in association with tomato seed.

Batuman, O.; Osei, M. K.; Mochiah, M. B.; Lamptey, J. N.; Miller, S.; Gilbertson, R. L.