Aims: Bacterial kiwifruit canker disease, caused by Pseudomonas syringae pv. actinidiae (Psa) was detected in north-west Portugal in 2010, and has since caused significant losses. The objectives of this work were to characterize the Portuguese population(s) of Psa and to define the actual prevalence of Psa biovars in the most productive kiwifruit region in Portugal.
Methods and results: Isolates obtained from Actinidia deliciosa orchards were characterized by morphological, biochemical, physiological, fatty acids and molecular tests (PCR, BOX-PCR, duplex-PCR, multiplex-PCR and RFLP), phaseolotoxin, housekeeping and effector genes and pathogenicity. Results established that only Psa biovar 3 is present in the north-west of Portugal, despite phenotypic and genetic variability among the isolates.
Conclusions: This work provides new information on P. syringae pv. actinidiae (Psa) genetic profile in Portugal, indicating for the first time, that two genetically different subpopulations of Psa biovar 3 are present.
Significance and impact of the study: A new subpopulation of Psa biovar 3 was found for the first time in Portugal, contributing to increase knowledge about this population worldwide and to support further understanding of the impact of Psa.
Keywords: Actinidia; Portugal; Psa biovar 3; Pseudomonas syringae pv. actinidiae; kiwifruit bacterial canker.
© 2018 The Society for Applied Microbiology.