Isolates of grapevine yellow speckle viroid (GYSVd-1) were found in Saraburi province,
having
366 and 367 bp in size,
and showed 96% sequence homology with Australian GYSVd-1.
GYSVd cDNA probe was proven to be sensitive and highly specific to GYSVd-1.
This cDNA probe could detect very
low amount of the viroid even in the symptomless samples.
Thus, GYSVd-1 cDNA probe would be very
useful for plant quarantine or viroid free certification schemes,
since the large number of samples could
be tested for viroid infection with high accuracy.
Key words: grapevine, RT-PCR, GYSVd-1, viroids, cDNA probe