Pathogen Responsible for Psyllid Yellow Discovered

The bacterial pathogen that could be responsible for psyllid yellows, a leaf disease that kills solanaceous plants, has been identified by researchers from the University of California Riverside. The disease is spread from plant to plant by psyllid, a sap-sucking insect. Psyllids secrete a toxic saliva during feeding that has been known to cause yellowing of tomato and potato leaves. The cause of this symptom, however, has been a mystery for over a century.

Allison Hansen and her colleagues named the pathogen Candidatus Liberibacter psyllaurous. The new bacterium is closely related to huanglongbing or the citrus greening disease pathogen, so named because the disease causes the citrus fruit to retain some green spots even when the fruit is ripe.

The discovery has the potential to help plant breeders develop resistant cultivars. In the United States, psyllid yellows resulted in yield losses up to 85 percent and 50 percent in commercial tomato crops in 2001 and 2004, respectively.

Read the complete article at http://info.ucr.edu/cgi-bin/display.cgi?id=1903 Subscribers can download the paper published by Applied and Environmental Microbiology at http://aem.asm.org/cgi/reprint/AEM.01268-08v1