AGROINFECTION OF PEAR AND APPLE WITH DAPPLE APPLE VIROID RESULTS IN SYSTEMIC INFECTION

Dapple apple viroid (DAVd) is a member of the apple scar skin viroid (ASSVd) group of viroids.
Attempts to transmit these viroids to herbaceous hosts have been unsuccessful; transmission to woody hosts has been primarily by grafting from infected materials.
In order to complete Koch’s postulates and to show that DAVd is responsible for the systemic infection in infected trees, cloned dimeric copies of DAVd were inserted into a binary vector containing the CaMV35S promoter, which was subsequently transformed into Agrobacterium strain LBA4404. Apple and pear seedlings were agroinoculated on their stems with a solution of the Agrobacteria containing the plasmid pBI121 :DAVd construct.
Seedlings were kept in a growth chamber and monitored for viroid infection by dot and Northern blot hybridization analyses.
A few seedlings of pear and apple became systemically infected with DAVd and the viroid progeny were confirmed by nucleotide sequence analysis to be identical to that of the inoculum.

XVII International Symposium Virus and Virus-Like Diseases of Temperate Fruit Crops

S.F. Zhu, A. Hadidi, R.W. Hammond

agroinfection, apple scar skin viroid, dapple apple viroid

https://doi.org/10.17660/ActaHortic.1998.472.81