ANALYSIS OF THE DISTRIBUTION OF APPLE PROLIFERATION PHYTOPLASMA SUBTYPES IN A LOCAL FRUIT GROWING REGION IN SOUTHWEST GERMANY

PCR-RFLP using apple proliferation (AP) phytoplasma-specific primers has been employed to study the distribution of AP phytoplasma subtypes in commercial apple orchards as well as in abandoned or scattered orchards in a local fruit growing region of Palatinate in Southwest Germany.
More than 50 samples from symptomatic trees were analysed.
The AP phytoplasma subtype AP was found in 72% of the samples whereas the subtypes AT-2 and AT-1 were detected only in 16% and 12% of the samples, respectively.
Important differences became evident regarding the distribution of the subtypes in different kinds of orchards.
The AP subtype was exclusively found in commercial orchards.
In abandoned or scattered orchards the AT-1 subtype was predominant.
The latter subtype was never detected in commercial orchards.
The subtype AT-2 showed an intermediate distribution and was found in both kinds of orchards.
Eleven per cent of the samples from commercial orchards were of AT-2 subtype and 36% of the samples from abandoned or scattered orchards.
The predominance of the AP subtype is in accordance with the previously reported European distribution of the subtypes.
Our data indicate that the AP subtype either spreads more efficiently by the insect vector or multiplies more efficiently in the plant.

XIX International Symposium on Virus and Virus-like Diseases of Temperate Fruit Crops – Fruit Tree Diseases

W. Jarausch, N. Schwind, B. Jarausch, G. Krczal

Apple, apple proliferation, phytoplasma, PCR, RFLP, Germany

https://doi.org/10.17660/ActaHortic.2004.657.67