Role of 'Candidatus Liberibacter solanacearum' and Bactericera cockerelli Haplotypes in Zebra Chip Incidence and Symptom Severity
Grimm, K.D. S.; Mustafa, T.; Cooper, W. R.; Munyaneza, J.E.
American Journal of Potato Research 95(6): 709-719
2018
ISSN/ISBN: 1099-209X
DOI: 10.1007/s12230-018-9678-5
Accession: 066376920
Two haplotypes of the pathogen, Candidatus Liberibacter solanacearum,' (Lso) and four haplotypes of the insect vector, Bactericera cockerelli, are associated with zebra chip disease of potato. Whether disease severity or incidence is influenced by pathogen or insect haplotype is poorly understood. The role of Lso A' and B,' transmitted by three haplotypes of B. cockerelli, on disease severity and incidence in eight potato cultivars was analyzed. Both haplotypes of Lso induced tuber symptoms. In general, Lso B caused higher incidence of symptoms, and greater reduction in tubers compared with Lso A. Lso B was associated with more severe tuber symptoms, producing fewer mild or moderate tuber symptoms. Lso A was associated with less severe tuber symptoms, despite being able to induce severe symptoms. Disease incidence, tuber yield, and symptom severity ratings were not dependent upon the psyllid haplotype transmitting the pathogen, suggesting that pathogen, not insect haplotype affects Lso transmission. ResumenDos haplotipos del patogeno Candidatus liberibacter solanacearum (Lso) y cuatro haplotipos del insecto vector, Bactericera cockerelli, estan asociados con la enfermedad de la papa rayada. Lo que es la severidad de la enfermedad o la incidencia, y si estan influenciadas por el haplotipo del patogeno o del insecto, esta pobremente entendido. Se analizo el papel de Lso A y B, transmitido por tres haplotipos de B. cockerelli en la severidad e incidencia de la enfermedad en ocho variedades de papa. Ambos haplotipos de Lso indujeron sintomas en el tuberculo. En general, Lso B causo mayor incidencia de sintomas y mayor reduccion en tuberculos en comparacion con Lso A. Lso B se asocio con sintomas mas severos de tuberculo, produciendo pocos sintomas ligeros o moderados. Lso A se asocio con sintomas menos severos de tuberculo, a pesar de ser capaz de inducir sintomas severos. La incidencia de la enfermedad, el rendimiento de tuberculo y las calificaciones de severidad de sintomas no dependieron del haplotipo del psylido transmisor del patogeno, lo cual sugiere que el patogeno, no el haplotipo del insecto, afecta la transmision del Lso.