Objective: To isolate and identify the causal agent of ginger rhizome rot in Jalpan, Puebla and to evaluate its pathogenicity and in vitro sensitivity to bactericides. Design/methodology/approach: Bacteria with similar morphology were isolated from ginger rhizomes with rot. Strain CPB04 was biochemically characterized and identified by 16S rRNA gene sequencing. In vitro sensitivity was evaluated with nine commercial bactericides and pathogenicity in ginger rhizomes and organs of 11 plant species by injection of a suspension containing 3x108 CFU mL-1. Results: The biochemical characterization of strain CPB04 showed similarity with Pectobacterium. Sequencing of the 16S rRNA gene of strain CPB04 identified it with 100% similarity to Pectobacterium brasiliense strain CP047495.1. P. brasiliense CPB04 was sensitive in vitro to copper formulations and resistant to kasugamycin. It caused organ rots in sweet potato (Ipomoea batatas), onion (Allium cepa), chili (Capsicum annuum), jicama (Pachyrhizus erosus), tomato (Solanum lycopersicum), ginger (Zingiber officinale), potato (Solanum tuberosum) and radish (Raphanus sativus). Implications of the study: Pectobacterium brasiliense is a highly virulent pathogen with potential to infect new hosts. Rot diseases are a global problem in agriculture. This is the first report in Mexico of P. brasiliense as a causal agent of rot in ginger. Findings/conclusions: Pectobacterium brasiliense is the causal agent of ginger rhizome rot in Jalpan, Puebla. The tuberous root of jicama may be a new host of Pectobacterium brasiliense. Pectobacterium brasiliense is sensitive in vitro to copper oxychloride.
Alvarez-Hornia et al. (Mon,) studied this question.