Isolation and characterization of Pseudomonas syringae isolates affecting stone fruits and almond in Montenegro

Nevena Zlatković,Tamara Popović,Anđelka Prokić,Aleksa Obradović,Jelena Menković

doi:10.1007/s41348-020-00417-8

Nevena Zlatković, Tamara Popović + Show 3 more

Open Access

https://doi.org/10.1007/s41348-020-00417-8

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Abstract

In Montenegro, stone fruit species are grown on intensive and semi-intensive commercial plantations. However, almond production is mainly organized on family gardens and for household consumption. During two seasons (2017–2018), we surveyed apricot, peach, nectarine, sweet cherry, Japanese plum, and almond orchards for the presence of bacterial diseases at different geographical locations in Montenegro. From leaf, petiole and fruit lesions, branch or twig cankers, and necrotizing buds, a total of 29 isolates were obtained and subjected to identification based on their morphological, pathogenic, biochemical, and molecular characteristics. Pathogenicity of the isolates was confirmed by reproducing the symptoms on leaves, fruits, and twigs of the corresponding host plants. The biochemical tests indicated that the isolates belong to Pseudomonas syringae. However, isolates’ characterization showed variation in their phenotypic and molecular features. The presence of the syrB gene and ice nucleation activity grouped most of the isolates within pathovar syringae. The results of rep-PCR using the BOX primer revealed high genetic diversity of isolates. Multilocus sequence analysis (MLSA), using four housekeeping genes, showed that 27 isolates belong to the genomic species 1, P. syringae sensu stricto, corresponding to P. syringae phylogroup 2. However, isolates from the same phylogroup 2 did not form a monophyletic group. One strain isolated from apricot was most distinct and similar to members of genomic species 2, phylogroup 3. All tested isolates showed significant levels of resistance to copper sulfate and high level of sensitivity to streptomycin sulfate in vitro.

Highlights

The genus Pseudomonas is one of the most complexes in bacterial taxonomy
Journal of Plant Diseases and Protection (2021) 128:391–405 cause diseases on plants belonging to Prunus spp. (Young 1987; Kamiunten et al 2000; Ménard et al 2003; Kaluzna et al 2016): these pathovars are distributed throughout PG1, PG2 and PG3 of the P. syringae species complex (Ruinelli et al 2019)
A total of 29 bacterial isolates obtained from different stone fruit species and almond were characterized in this study (Table 1)

Summary

Introduction

The genus Pseudomonas is one of the most complexes in bacterial taxonomy. The Pseudomonas syringae phylogenetic group comprises 15 recognized bacterial species closely related to P. syringae and more than 60 pathovars (Gomila et al 2017). The classification is defined based on the host range and symptomatology, Pseudomonas syringae is a globally important plant pathogen, causing different diseases in more than 180 host plant species (Bultreys and Kałużna 2010). In the European area, P. syringae pathovars and races were confirmed to cause bacterial canker in stone fruit orchards in Germany (Hinrichs-Berger 2004), Belgium (Gilbert et al 2009), Poland (Sulikowska and Sobiczewski 2008; Bultreys and Kałużna 2010; Kaluzna et al 2010), Serbia (Balaž et al 2016), UK (Hulin et al 2018), and Italy (Giovanardi et al 2018)

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