The detection of MLOs associated with pear decline in pear trees and pear psyllids by polymerase chain reaction

摘要

PCR using primers to sequences in the 16S RNA gene of pear decline phytoplasma were used for the specific detection of phytoplasmas associated with pear decline in pear trees and in the psyllid vector of the disease. No product was obtained with theprimers from DNA prepared from healthy pear tissue or from periwinkle (Catharanthus roseus) plants infected with one of several phytoplasmas including aster yellows, clover, phyllody, apple proliferation, plum leptonecrosis, apricot chlorotic leaf roll,Moliere's disease and elm yellows. A nested PCR technique using a preliminary amplification with primers to sequences located outside the fragment amplified by PD specific primers was the most consistent means of obtaining a product from psyllid DNA preparations and single insects.