Detection and Identification of some Pseudomonas Species causing Soft Rot using TUF Gene

رديابي و شناسايي برخي از گونه هاي جنس سودوموناس عامل پوسيدگي نرم با استفاده از ژن tuf

Introduction: Soft rot caused by pectolytic bacteria makes annual production and storage losses throughout the world. This study aimed to detect and identify pathogenic Pseudomonas causing soft rot in some of the vegetables and ornamentals. Materials and methods: During the growing seasons of 2015–17, plant samples of eggplant, maize, radiator plant, sweet pepper and tomato with water soak and soft rot symptoms were collected. Biochemical and morphological features were characterized according to the standard bacteriological criteria. The tuf encoding gene from these representatives was amplified using Bac-tuf-F and Bac-tuf-R primers, subjected to sequencing and aligned in the NCBI. Results: Total of 120 isolates were recovered from the samples. Based on synthesizing pectic enzymes, five putative Pseudomonas strains were selected. Based on the DNA sequence-based phylogeny, in combination with biochemical and morphological characteristics, these soft rot Pseudomonas were identified as Pseudomonas aeruginosa, P. entomophila, P. mosselii and P. putida. Koch's postulates were verified by re-isolating the strains from inoculated plant segments. Discussion and conclusion: To the best of our knowledge, this is the first evidence of the pathogenicity of P. aeruginosa on tomato, P. entomophila on sweet pepper and P. putida on eggplant. Furthermore, this study firstly reports the association of P. aeruginosa and P. mosselii with soft rot in maize and radiator plant, respectively.