BARK SPLIT DISEASE OF PRUNE TREES AND ITS ASSOCIATION WITH STRAINS OF APPLE CHLOROTIC LEAF SPOT

Bark split disease was identified as a virus disease several years ago in 1956. It was found and described in France in 1965. A variety of French prune P 707 appears to be very sensitive to bark split and severe damage was observed in orchards planted with this variety.
Indexing of prune trees shows that all the trees infected with bark split are also contaminated by strains of apple chlorotic leaf spot (CLSV). Heat treatment of trees with bark split leads to a simultaneous elimination of chlorotic leaf spot and bark split.
Screening through Sorbus aucuparia eliminates CLSV and bark split.
When bark split is transmitted from prune to Malus then back inoculated onto prune, these trees show bark split symptoms.

The presence of CLSV was ascertained by indexing on woody and herbaceous indicators and by serological testing.

We put forward the hypothesis that bark split could be induced by some strains of CLSV. After observing the variability of symptoms induced by CLSV, we isolated strains of this virus associated with different symptoms and especially with bark split of prune trees.
These strains were inoculated onto Chenopodium and studied in this plant.
Several isolates of CLSV, free from other contaminants, were back inoculated from Chenopodium to the woody virusfree plants, peach and prune.
Two years later, symptoms of bark split developed on the prune trees.

Indexing by mechanical transmission and serological tests performed with material from these trees showed the presence of CLSV. Hence it appears that bark split disease of prune trees is induced by some strains of CLSV.

IX International Symposium on Fruit Tree Virus Diseases

J. Dunez, C. Marenaud, R. Delbos

https://doi.org/10.17660/ActaHortic.1975.44.14