Agents Resembling or Altering Virus Diseases

Rasta Disease of Tomato in Ghana is Caused by the PospiviroidsPotato spindle tuber viroidandTomato apical stunt viroid

“…This is in agreement with previous reports that PSTVd isolates differentially infected cultivars of tomato and potato (Hammond and Zhao 2000;Owens and Hammond 2009;Sano et al 1992). The findings that (i) few plant species tested developed symptoms following inoculation with these viroids (e.g., only a single tomato cultivar in the present study) and (ii) symptomless infections were detected in other species (various solanaceous species in the present study) are in agreement with previous studies of the host range of PSTVd and TASVd and further show the complexity of the viroid-host interaction (Diener 2003;Ding 2009;Flores et al 2005Flores et al , 2014Hull 2013;Matsushita and Tsuda 2015;Navarro et al 2012;Tabler and Tsagris 2004). Furthermore, although the host range studies of PSTVd and TASVd conducted by Matsushita and Tsuda (2015) and in the present study are difficult to compare directly because of focusing on plant species commonly imported into Japan versus indicator plants and agricultural plants, respectively, both studies revealed few species that developed symptoms but a relatively broad host range when symptomless hosts were included.…”

“…Viroids replicate in the nucleus (members of the family Pospiviroidae) or in plastids (members of the family Avsunviroidae) of infected cells (Branch and Robertson 1984;Daros et al 1994;Di Serio et al 2014;Ding 2009;Flores et al 2000Flores et al , 2009. A number of comprehensive reviews on viroids have been published (Diener 2003;Ding 2009;Flores et al 2005Flores et al , 2014Gucek et al 2017;Hull 2013;Navarro et al 2012;Tabler and Tsagris 2004).…”