TYLCV detection by PCR. Since dot
blotting failed to consistently detect
TYLCV in highly resistant genotypes, the
four EP extracts were used as templates for
PCR amplification. Only EP1 and EP2
yielded DNA of quality to be directly used
in PCR (Table 2). Only erratic amplifications
(+–) were obtained with the fast sap
extraction procedures EP3 and EP4, even
after serial dilutions, probably due to the
existence of sap contaminants that may
inhibit Taq DNA polymerase amplification.
These extracts should be purified with
resins or columns before their use for PCR
amplification. EP2 was selected for further
assays as being more effective than EP1 in
extracting high-quality TYLCV DNA.