During October-November/2011, blackcurrant (Ribes nigrum L.) and redcurrant (Ribes rubrum L.) shrubs from Ontario, Canada that exhibited symptoms of leaf redness and downward curling were tested to verify phytoplasma presence. Total DNA was extracted and used in a nested PCR assay with universal primers that target the phytoplasma 16S rRNA gene in nested reaction. Amplicons were obtained for all the symptomatic plants collected and phytoplasma sequence from both blackcurrant and redcurrant plants showed a 99% sequence identity to those of members of group 16SrX, subgroup 16SrX-A. Virtual RFLP of the R16F2n/R2 amplicons yielded patterns identical to those of ‘Ca. P. mali’ (AJ542541). Phylogenetic analysis based on the 16S rDNA sequences confirmed RFLP results. Phytoplasmas of group 16SrX have been previously reported in Ontario, affecting Prunus and Pyrus species. However, our results represent the first record of a 16SrX-A infecting blackcurrant and redcurrant in Canada and North America, and provide a valuable tool for further epidemiological studies of a 16SrX phytoplasma in these two plant species.
Detection and identification of a phytoplasma affecting black currant and red currant shrubs in north America
BERTACCINI, ASSUNTA;
2012
Abstract
During October-November/2011, blackcurrant (Ribes nigrum L.) and redcurrant (Ribes rubrum L.) shrubs from Ontario, Canada that exhibited symptoms of leaf redness and downward curling were tested to verify phytoplasma presence. Total DNA was extracted and used in a nested PCR assay with universal primers that target the phytoplasma 16S rRNA gene in nested reaction. Amplicons were obtained for all the symptomatic plants collected and phytoplasma sequence from both blackcurrant and redcurrant plants showed a 99% sequence identity to those of members of group 16SrX, subgroup 16SrX-A. Virtual RFLP of the R16F2n/R2 amplicons yielded patterns identical to those of ‘Ca. P. mali’ (AJ542541). Phylogenetic analysis based on the 16S rDNA sequences confirmed RFLP results. Phytoplasmas of group 16SrX have been previously reported in Ontario, affecting Prunus and Pyrus species. However, our results represent the first record of a 16SrX-A infecting blackcurrant and redcurrant in Canada and North America, and provide a valuable tool for further epidemiological studies of a 16SrX phytoplasma in these two plant species.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
