Phylogenetic position and characteristics of the new group
of Pseudomonas spp. causing bacterial canker on cherry
Pseudomonas syringae is a causal agent of bacterial canker of stone fruit trees. It attacks all organs of the aboveground parts of the trees and it is found in all
fruit trees growing areas in the world. The greatest damage occurs in orchards and nurseries of stone fruit trees, especially in sweet and sour cherries. Necrosis
on the main trunk and branches sometimes lead to the death of entire trees. In young orchards losses causing by this disease can reach even 75%. On sweet and
sour cherry, two pathovars of P. syringae: syringae (Pss) and morsprunorum (including race 1 and 2-Psm1 and Psm2) are known.
The aim of this study was characteristics and determination of the phylogenetic position of atypical group isolates from sour cherry by PCR MP, rep-PCR and MLST.
Repetitive PCR ERIC, BOX, REP and IS50 PCR,
Melting Profile PCR (PCR MP)
Multilocus Sequence Typing
The results of rep-PCR, PCR MP and MLST allowed for distinction of group of sour cherry isolates showing atypical characters in phenotypic tests (similar
to Pss) and in pathogenicity assay (they caused superficial lesions as strains of Psm1 and 2).
This is not describet yet group of isolates was found to be highly homogenic.
Their phylogenetic position, beetween Pss and Psm strains is still not well defined but it suggests that their constitute an intermediate form between
this two taxa.
The further study towards description of the will be conducted.
Fig. 2. Dendrogram showing the genetic
diversity of studied strains of Pss, Pss(A),
Psm1, Psm2 based on data of PCR MP
using UPGMA analysis and Dice’a coefficient.
Fig. 1. Dendrogram showing the genetic diversity
among strains Pss, Pss(A), Psm1, Psm2 obtained from
concatenated data from REP, ERIC, BOX and IS50 PCR
MP using UPGMA analysis and Jaccard’s coefficient.
Fig. 3. Maximum Likelihood tree showing phylogenetic relationship between studied strains of Pss, Pss(A), Psm1, Psm2 based on sequences of genes gapA, gltA, gyrB and rpoD. Bootstrap values (expressed as percentages of 1000
replications) are given at the nodes. Bar – estimated nucleotide substitutions per site.
gapA gltA gyrB rpoD
New pathogenic group
of isolates from sour cherry
New pathogenic group
of isolates from sour cherry
New pathogenic group
of isolates from sour cherry
Monika Kałużna, Joanna Pulawska,
Research Institute of Horticulture, Pomology Division, Pomologiczna 18 str., Skierniewice, Poland
During monitoring conducted in 2007-2011
from 25 of 63 orchards of stone fruit trees
located in different regions of Poland 153
Pseudomonas isolates were obtained.
Based on results of LOPAT, GATTa and
L-lactate tests despite well known stains
of Pss, Psm1 and Psm2, the atypical group
of strains, not producing esculine and
utilizing L-lacate as Pss strains but showing
atypical pathogenic abilities as Psm were
found.
This group of atypical strains, named Pss(A)
was originating from sour cherry.