RESISTANCE IN ESTABLISHED AND EXPERIMENTAL APPLE ROOTSTOCKS TO APPLE PROLIFERATION DISEASE

The apple proliferation MLOs persist the winter in the root system.
Under these circumstances it appears to be possible to control the disease by the use of resistant rootstocks.
To screen for resistance, rootstocks M 2, M 7, M 9, M 11, M 13, M 16, M 26, M 27, MM 104, MM 106, MM 111, A 2, ‘Bittenfelder Sämling’, ‘Bemali’, P 1, P 2, P 16, P 18, and P 22 as well as a number of apomictic rootstock selections were observed under natural infection conditions and/or after graft inoculation.
All established and the more recent clonal rootstocks responded similarly to the disease.
They usually survived infection but their vigor was affected and they remained infected throughout the observation period.
By contrast, a considerable mortality was observed among several apomictic rootstock selections.
However, in a few apomictic rootstocks, symptom remission was observed.
All or most trees of these selections recovered completely, and in most cases no MLOs could be detected in the recovered trees.

XV International Symposium on Fruit Tree Diseases

E. Seemüller, S. Kartte, L. Kunze

https://doi.org/10.17660/ActaHortic.1992.309.35