POSSIBLE RELATIONSHIPS AMONG POME FRUIT VIRUSES DETECTED IN GRAFT TRANSMISSION TRIALS

In simultaneous graft transmission trials with budwood of commercial varieties of apple, pear and quince, from different Italian fruit districts, the co-identity of apple chlorotic leaf spot virus (CLSV) and pear ring mosaic virus (PRMV) has been confirmed.
The sensitivity of Spy 227 to Spy decline virus (SDV) in the inoculations with apple budwood has always been as good as that of quince C7/1 and of Pyronia veitchii, but rare with pear and quince sources.
P. veitchii has proved to be more sensitive to quince sooty ring spot virus (QRSV) than C7/1. Jules d’Airoles has been the best indicator for vein yellows virus (VYV). An unspecific reaction attained quite often with apple and pear budwood on the indicator Pirus communis L. A. 62 seems to be correlated with SDV and QSRV, and quite likely also with VYV.

The data acquired seem to prove that SDV and QRSV are identical; a close affinity or identity appears to exist between such viruses and VYV. Platycarpa scaly bark and Platycarpa dwarf are apparently caused by the same virus.
On the basis of the fruit symptoms obtained in the top-grafting inoculations, a close relationship, or perhaps identity, seems to exist between rough skin virus (RSV) and star crack virus (SCV). Russet ring virus (RRV), on the contrary, appears to be a distinct entity, although quite close to RSV and SCV. Apparently, the three viruses are not frequently latent in pome fruit trees.

IX International Symposium on Fruit Tree Virus Diseases

E. Refatti, R. Osler

https://doi.org/10.17660/ActaHortic.1975.44.32