REPRODUCTION OF APPLE FRUIT CRINKLE DISEASE SYMPTOMS BY APPLE FRUIT CRINKLE VIROID

To ascertain whether apple fruit crinkle associated viroid (AFCaVd) is the causal agent of apple fruit crinkle (AFC) disease or not, viroid-free apple trees of cvs.
Ohrin, Jonathan, Starking Delicious and NY58-22 crab apple were back-inoculated in 1992 and again in 1994 (only in 1992 to cv.
Jonathan) with chip buds of apple seedlings which had been inoculated with electrophoretically purified AFCaVd by razor slashing.
By 1996, all inoculated trees of each cultivar and NY58-22 exhibited the typical AFC symptoms characteristic of individual cultivars and NY58-22, respectively, i.e severe fruit crinkling (sFC) and necrosis in the fruit flesh (NFF) on cv.
Ohrin, fruit crinkling (FC) and fruit dappling (FD) on cv.
Jonathan, blister bark (BB) on cv.
Starking Delicious, sFC, NFF, FD and BB on NY58-22. In contrast, all non-inoculated trees used as control remained symptomless.
Furthermore, AFCaVd was detected from all inoculated trees by bidirectional polyacrylamide gel electrophoresis, but not from all non-inoculated trees.
Consequently, we conclude that AFCaVd is the causal agent of AFC and propose to call this viroid apple fruit crinkle viroid (AFCVd). Another inoculation tests using the same inocula suggested that AFCVd is also associated with a bark disorder on apple cv.
Nero 26 reported by Matsunaka and Machita (1987) in Japan.

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

T. Ito, K. Yoshida

apple fruit crinkle viroid, back-inoculation, graft-transmissible bark disorder

https://doi.org/10.17660/ActaHortic.1998.472.78