Identification of fruit tree phytoplasmas and their vectors in Bosnia and Herzegovina

Abstract

Surveys were carried out in autumn 2004 and spring 2005 in the traditional areas dedicated to pome and stone fruit cultivation in Bosnia and Herzegovina to assess the presence, distribution and incidence of phytoplasma diseases in fruit trees. The occurrence of psyllid vectors was also considered. The detection of phytoplasmas in plant and insect samples and their identification were carried out by symptom observations in the field, double antibody sandwich‐enzyme linked immunosorbent assay (DAS‐ELISA), nested polymerase chain reaction (nested‐PCR) and restriction fragment length polymorphism (RFLP) analyses. Laboratory analyses showed the presence of phytoplasmas belonging to: (i) 16SrX group, subgroup A (‘Candidatus Phytoplasma mali’) in 23 out of 25 apple samples, in 4 groups out of 18 of Cacopsylla picta (synonym Cacopsylla costalis) and in 2 groups out of 9 of Cacopsylla melanoneura; (ii) 16SrX group, subgroup C (‘Candidatus Phytoplasma pyri’) in 11 out of 30 pears samples and in 2 groups out of 9 of Cacopsylla pyri; (iii) 16SrX group, subgroup B (‘Candidatus Phytoplasma prunorum’) in 4 apricots, 2 peaches out of 42 stone fruit samples and in 1 group out of 14 of Cacopsylla pruni. The presence of different subtypes of Candidatus Phytoplasma mali, both in apple trees and in insects, was proven.