The ultrastructural changes in leaf cells of Chenopodium quinoa caused by Arabis mosaic virus (ArMV) infection have been investigated in electronmicroscopic studies. The techniques of negative staining and embedding sections from leaves in epoxy resin were applied. ArMV virions have been found in the cytoplasm and either singularly scattered or forming different arrangements in the vacuoles as well. Tubules with virions have been observed only rarely. Two types of inclusions have been identified and their structure illustrated. Ultrastructural changes in leaf cells of C. quinoa caused by ArMV infection are partially similar and partially different from those occurring on Phaseolus vulgaris plants infected with ArMV. It might suggest that some ultrastructural changes are typical for the virus and some are characteristic for the host plant.

A total of 94 pectolytic and 60 nonpectolytic Pseudomonas isolates were obtained from 250 samples of rotted vegetable specimens representing various economically important vegetables. The isolates were identified on the basis of standard biochemical tests. Pseudomonas fluorescens biovar V and II and Pseudomonas putida were the most abundant species among pectolytic isolates and Pseudomonas fluorescens biovar I among nonpectolytic ones. Only 3 Pseudomonas viridiflava isolates were identified and all of them were obtained from potato. Isolates of pectolytic phenotype were scattered among nonpectolytic ones irrespective of their taxonomical status. Isolates identified biochemically, as Pseudomonas marginalis were also present in nonpectolytic group. PCR method is unsuitable for identification and differentiation of bacteria belonging to pectolytic fluorescens Pseudomonas group due to great diversity of species. However, the results of PCR amplification of the genes encoding pectate lyase suggest that genes responsible for production of this enzyme may also be present in isolates of nonpectolytic phenotype.

In this paper we present the first identification of the Tomato clack ring virus isolated from zucchini with mosaic and deformation of leaves in Poland. Immunosorbent electron microscopy, ELISA test and IC-RT-PCR confirmed the identification of TBRV. RNA extracted from purified virus (size about 7.4 kb and 4.6 kb) was characteristic to this virus.

From the naturally infected cucumber plane spherical virus was isolated that mainly on basis of its serological properties has been identified as Tomato black ring virus (TBRV). Using antiserum against TBRV-ED for the specific crapping of virus followed by PCR test (immunocapture-RT-PCR) allowed co distinguish TBRV from related viruses, especially Beet ringspot virus (BRSV). Presence of as many as rwo satellite RNAs should be found as a unique feature of the cucumber isolace.