Gesunde Pflanzen (2004) 56, 27-31

K. Rebenstorf and C. Büttner (2004)
Eine kleine Studie zum Auftreten des Sharka-Virus (Plum pox potyvirus) in Pflaumenobstbeständen im Berliner Umland
[A short investigation of the distribution of Sharka virus in plum orchards in the periurban area of Berlin]
Gesunde Pflanzen 56 (1), 27-31
Abstract: In recent years, keepers of plum orchards in the periurban area of Berlin have repeatedly observed chlorotic ring spots and chlorotic mottling on the leaves of plum trees which might correlate to an infection with the Sharka virus. Thus, leaves were sampled from symptomatic and asymptomatic plum trees in four orchards in autumn 2000 and tested by bioassay, electron microscopy for virus infection, and serological and molecular assays for plum pox polyvirus (PPV) infection. Some samples were also analyzed by restriction fragment length polymorphism (RFLP) analysis of reverse transcription polymerase chain reaction (RT-PCR)-amplified DNA fragments. The RFLP profiles of amplified fragments of the C-terminal part of the PPV coat protein have been shown to be useful for differentiation of PPV isolates, and the polymorphism correlates with serogrouping of PPV strains according to Wetzel et al. (1991a). Plum pox potyvirus was detected in 52% of all tested symptomatic leaf samples (13 of 25) and 62% of all tested plum cultivars (10 of 16) by DAS enzyme-linked immunosorbent assay (ELISA). The proportion of PPV-infected samples and cultivars in different orchards was heterogeneous (15% to 100%). The symptom expression of samples testing positive for PPV in DAS-ELISA varied strongly between cultivars. Sharka disease in plum trees was widely distributed in the four orchards tested in the area of Berlin. Two samples from different orchards in the western and northeastern parts of the city were analysed by RT-PCR and RFLP analysis using the restriction enzyme Rsa I. This enzyme was previously described to be useful for strain differentiation. The D strain of PPV, considered to be the nonepidemic form of PPV, was detected in the samples analysed. The more aggressive M strain, considered the epidemic form, was not detected. However, for accurate evaluation of the occurrence of different strains of PPV, it is necessary to investigate a larger number of isolates obtained from plum orchards from the Berlin periurban area.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: German)
Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
identification/taxonomy

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Plum pox virus	Plum/prune (Prunus domestica)	Germany