Candidatus Liberibacter solanacearum (Ca. Lso) is a species of bacterium that survives exclusively within plant phloem and insect tissue. Consequently, it has resisted laboratory cultivation to this point, and an official exemplar of culture does not exist, hence the designation “Candidatus.” The Lso species is divided into groups known as haplotypes (haploid genotypes) based on genetic variability, plants affected, insect vectors and geographic distribution. Haplotypes A and B are widespread throughout the U.S., Mexico, Central America and New Zealand. These variants cause zebra chip disease in potato and yellows disease in several additional members of Solanaceae, and are spread by the potato-tomato psyllid, Bactericera cockerelli (Hemiptera). Haplotypes C, D and E are present throughout Europe and North Africa, causing severe yellows disease in members of Apiaceae, including carrot and celery. These are vectored by two species of carrot psyllids: Trioza apicalis and Bactericera trigonica. Research shows that T. apicalis and B. trigonica cannot feed efficiently on solanaceous crops, thereby limiting the spread of Lso in Europe. Bactericera cockerelli and its vectored haplotypes have not been detected in Europe. Nevertheless, transmission pathways are dynamic, and the potential for the introduction of zebra chip disease to the European potato market represents a significant phytosanitary risk. Accurate and timely diagnosis of plants infected with Lso is paramount to successful management throughout the growing season, including the establishment and transplanting phases. 

Agdia’s new AmplifyRP^® XRT assay for detection of Candidatus Liberibacter solanacearum provides growers from multiple cropping systems with varying levels of expertise with a powerful diagnostic tool.