Identification of Alternative Hosts of the Fastidious Bacterium Causing Citrus Greening Disease

Abstract

Citrus greening is a severe disease caused by a fastidious bacterium GFB# residing in the sieve tubes of its hosts[ It is an epidemic disease and is spread by insect vectors[ In Asia the Asian citrus psyllid Diaphorina citri Kuway! ama# is the vector for GFB[ For the epidemiological study an investigation of alternative hosts of GFB was made[ Four suitable hosts of the Asian psyllid that are considered as possible alternative hosts of GFB were investigated on graft!inoculation tests[ The multi! plication of GFB in plants was monitored by dot hybrid! ization using a GFB!speci_c DNA probe developed previously by us[ The results demonstrate that GFB can replicate in Chinese box orange Severinia buxifolia# and wood apple Limonia acidissima# but not in common jasmin orange Murraya paniculata var[ paniculata# and curry leaf Murraya euchrestifolia#[ Chinese box orange is a good host in which GFB replicates as well as it does in its citrus hosts[ Wood apple is a transient host in which GFB exists temporarily and disappears several months later[ Common jasmin orange and curry leaf are not hosts of GFB as they showed no detectable signals in dot hybridization tests throughout 0 year of experimentation[