Seed transmission of potato spindle tuber viroid, tomato chlorotic dwarf viroid, tomato apical stunt viroid, and Columnea latent viroid in horticultural plants

Seed transmission of Potato spindle tuber viroid (PSTVd), Tomato chlorotic dwarf viroid (TCDVd), Tomato apical stunt viroid (TASVd), and Columnea latent viroid (CLVd) has been investigated in some horticultural plants. The rate of seed transmission of PSTVd was found to be 0-90.2 % in tomato, 0.3 % in Capsicum annuum var. grossum, 0.5 % in C. annuum var. angulosum, 1.2 % in Glebionis coronaria, and 81 % in Petunia x hybrida. In the case of TCDVd and CLVd, transmission rates were 25 % in Petunia x hybrida and 5.3-100 % in tomato, respectively, indicating that the risk of spreading this disease worldwide via the international trade in horticultural plants is considerable. Furthermore, we investigated the distribution of PSTVd within the seed using in situ hybridization, and determined that PSTVd is present in the embryo and endosperm of PSTVd-infected tomato seeds.