Characterization of Pseudomonas syringae PV. syringae from diseased stone fruits in Kyrgyzstan and testing of biological agents against pathogen

Abstract

The plant diseases caused by the Pseudomonas syringae complex bacteria are economically important and occur worldwide on various plants, and it is as a pathogen that has not been the object of studies and little is known about its epidemiology in Kyrgyzstan. The conventional phenotypic (LOPAT, API tests) and PCR-assisted isolation were used for the identification of Pseudomonas syringae pv. syringae isolates from the affected organs of local stone fruits, such as peach (Prunus persica), cherry (Prunus subgen), apricot (Prunus armeniaca), and plum (Prunus salicina) samples taken from the Chy, Issuk-Kul, and Batken regions of the country. 16S rRNA gene amplification was performed with primers 27F (5'-AGA GTT TGA TCC TGG CTC AG -3') and 907R (5 '-CCG TCA ATT CCT TTG AGT TT-3') for the identification of obtained P.syringae pv. syringae isolates. From 40 primary isolates of Gram-negative rod-shaped bacteria, 12 were identified as Pseudomonas syringae pv. syringae, while the remaining isolates were identified as bacteria from Stenotrophomonas, Xanthomonas, Erwinia genera. The antagonist bio control agent-Streptomyces bacteria strains were screened and selected against the bacterial canker pathogen in in vitro experiments and on apricot seedlings in vivo conditions. Obtained results could encourage to develop a local bio-product based on this bioagent for spraying stone fruits with the initial manifestation of disease symptoms and to conduct preventive treatments in the fall and spring to increase the plant’s resistance to pathogens.