Comparison of Phenotypic and Genotypic Features of Pseudomonas syringae pv. syringae Isolated from Stone Fruits Using PCR-RFLP in Kohgiloye and Boyer Ahmad Province
Subject Areas : دو فصلنامه تحقیقات بیماریهای گیاهی
1 - plant protection, Islamic Azad University, Jahrom Branch
Keywords: Stone fruits, SyrB, Pseudomonas syringae pv. syringae, RFLP,
Abstract :
Bacterial canker of stone fruit trees caused by Pseudomonas syringae pv. syringae (Pss), is present in all areas where stone fruit trees are cultivated. It is one of the most important diseases of stone fruit trees in Iran. This disease causes deterioration in young trees and yield reduction in old trees (Agrios, 2005). During investigation in different regions of Kohgiloye and Boyerahmad province (Iran), plants showing bacterial canker symptoms were collected. A total of 30 gram-negative isolates were initially identified as Pseudomonas syringae pv. syringae. All isolates were studied for phenotypic, physiological, pathogenicity, nutritional characteristics and evaluation for syrB gene. Moreover, they were subjected to genetically analysis via RFLP. All isolates were rod shaped, gram negative, motile, and obligate aerobic. All of them showed positive reaction in catalase and hypersensitive reaction on tobacco. Additionally, they produced a fluorescent pigment on Kings’B medium. In LOPAT tests, oxidase, arginine dehydrolysis and potato rot were negative and hypersensitive reaction and levan production were positive. In numerical analysis of phenotypic characteristics using Ntsys-pc, all isolates were showed 90% similarity. Pathogenicity test shown that all strains were infectious on stone fruit plants regardless of their initial hosts. An approximately, a 752 bp fragment DNA, was synthetized using B1 and B2 specific primers. In RFLP test, five enzymes including kpnI, EcoRI, HaeIII, AluI and HindIII were applied on syrB gene. Only one enzyme, HaeIII, was able to cut syrB gene. Genetic fingerprint obtained from RFLP, were evaluated identical for all isolates. Results of phenotypic, pathogenicity, and RFLP tests signify that Pss strains isolated from stone fruits in Kohgiloye and Boyerahmad province, show high homogeneity.
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