Heart rot of Australian pineapples caused by Dickeya zeae

Abstract Pineapple plants (hybrid MD2) with bacterial heart rot were detected in a commercial plantation at Glasshouse Mountains, Queensland, November 2015. The strain BRIP64263 isolated from infected tissue was shown to be Gram negative soft-rotting bacterium capable of growth 41 ºC, and based on its culture properties provisionally identified as Dickeya . This compared other putative strains affecting banana (BRIP64262) potato (BRIP29490). Sequence analysis the recombinase A genes pineapple placed it phylotype I D. zeae , whereas II. confirmed by sequence comparisons for phosphofructose kinase, RNA polymerase aconitase which showed that is distinct infect pineapples hosts Australia overseas. Furthermore, phylogenetic replication initiation factor gene distributed among both phylotypes indicating multiple acquisitions or opportunistic infections this group pathogens. isolate, BRIP29490, Rahnella aquatica not likely pathogenic. It known whether new isolate represents an incursion has long been associated Australia. Further study required determine epidemiological characteristics strain, what threat poses Australian production.