Implementation of 16S rRNA Gene and RAPD-PCR for Detection of Ralstonia solanacearum Isolates

El-Kazzaz, Said A.; El-Sheikh, Mohamed A.; Hafez, Elsayed E.; Madkour, Samia A.; El-Gayyar, Soha M.

doi:10.21608/ejp.2011.228866

Implementation of 16S rRNA Gene and RAPD-PCR for Detection of Ralstonia solanacearum Isolates

Document Type : Original Article

Authors

¹ Plant Pathology Department, Faculty of Agriculture, Alexandria University, El-Shatby, Alexandria, Egypt

² Plant Pathology Department, Faculty of Agriculture, Damanhour University, Damanhour, Egypt

³ Plant Protection and Biomolecular Diagnosis Department, Arid Lands Cultivation Research Institute, City of Scientific Research and Technological Applications, New Borg El-Arab City 21934, Egypt

10.21608/ejp.2011.228866

Abstract

Six isolates of Ralstonia solanacearum were isolated from diseased potato tubers and three isolates of Pseudomonas fluorescens were recovered from the soil rhizosphere healthy potato plants. R. solanacearum isolates exhibited various degrees of wilting on aerial stems of three cultivars of potato. The antagonistic bacterium P. fluorescens had an inhibitory effect against R. solanacearum isolates. Identification of six isolates of R. solanacearum and two isolates of P. fluorescens were carried out using the total DNA isolated in polymerase chain reaction (PCR) analysis, where a region of the 16S rRNA gene had a molecular weight of 1550 bp was amplified by using universal primers. Eight primers (BAR, BAQ, 18, W, BIC 1, I, A9B4 and A9Al0) were used in the differentiation between R. solanacearum as well as the P. fluorescens isolates. Primers produced considerable polymorphism among the studied isolates. The phylogenetic tree based on the similarity matrix was carried using the UPGMA method and revealed the existence of two main clusters, indicating the relationship among the eight examined isolates.

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