Abstract

Bacterial soft rot diseases caused by Pectobacterium-Dickeya complex are the most important and yield losses diseases of potato crop worldwide. Loss due to these diseases in some years/fields under Iran condition is huge and destructive. To screen and characterize the causal agents, thirty bacterial soft rot isolates including 10 authentic pectolytic strains were investigated. Based on biochemical and physiological tests, the Iranian strains were identified as either Pectobacteriumcarotovorum subsp. carotovorum or P. carotovorum subsp. wasabiae. Sequence analysis of recA gene revealed that the strains closely related to Pectobacterium spp. To assess the genomic diversity, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was performed. PCR amplification of therecA gene followed by RFLP revealed 14 distinct RFLP groups. Here also, the same results were obtained and all 19 Iranian strains were assigned as eitherPectobacterium carotovorum subsp. carotovorum or P. carotovorum subsp.wasabiae.

Key words: Genetic diversity, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), recA gene, Pectobacterium spp.

Abbreviation

RFLP, Restriction fragment length polymorphism; AFLP, amplified fragment length polymorphism; RecA, recombinase A; NA, nutrient agar.