Analysis of the viroids distribution in different citrus tissues by RT-PCR and qPCR. For RT-PCR detection, CEVd-F194/R18 primer was used to detect CEVd from five citrus tissues. (A) Murcott oranges from Hsinchu; (B) Blood oranges from Yunlin; (C) Kumquat from Yilan; (D) Tankan from Taichung; (E) Lemon from Pingtung. Lane 1, exocortis symptom on rootstock; 2, root; 3, twig bark; 4, leaf; 5, healthy control; M, 100-bp molecular marker. (F) The quantification data of qPCR were collected among winter, 2011 to autumn, 2013 and the copy numbers of two viroids were measured by log10. The collected data of fruit were discontinuous in winter, 2011 and autumn, 2012. The collected data of leaf were only from one citrus. The bars represented the standard deviation errors.