In April and May 2009, phytoplasma symptoms were observed in several cultivars of oilseed rape (Brassica napus L. var. oleifera) growing in three trials located in the Experimental Farm of Padova University. The fields were established in October 2008 to test agronomic performance of different oilseed rape cultivars. Affected plants presented symptoms such as stunting, leaf reddening, green petals and extensive malformations of floral parts. When an inflorescence was affected only a small proportion of flowers set seeds at the end of the cycle. Among the 51 varieties cultivated in the fields 27 showed the described symptoms with a disease presence varying from 0.03 – 1.89% of the crop. Symptomatic samples from 6 plots of 5 varieties were collected and phytoplasma detection and identification was obtained with PCR assay using R16F2/R16R2 universal primers specific to the phytoplasma 16S rRNA gene (Lee et al., Phytopathology, 85, 728-735. 1995). PCR products of expected size (~1.2 kb) were obtained from all samples with symptoms but not from the 2 symptomless samples, collected as negative controls. RFLP analyses using TruI, BfaI, and HhaI restriction enzymes allowed to verify that amplicons from all positive samples showed identical profiles, undistinguishable from those of the European aster yellows phytoplasma (16SrI-B) reference strain. The results indicate that a ‘Ca. P. asteris’ related phytoplasma was associated with the disease. The same phytoplasma was already detected in winter oilseed rape in Czech Republic and, recently, in Greece (Bertaccini et al., Plant Pathology, 47, 317-324. 1998; Maliogka et al., Plant Pathology, 88, 792. 2009); therefore this new finding indicates some epidemic spreading of the disease. This is the first report of the association between ‘Ca. P. asteris’ and oilseed rape in Italy and studies to verify epidemiological behaviours of the disease in insect and weeds are in progress.
First report of ‘Candidatus Phytoplasma asteris’ associated with several cultivars of oilseed rape in Italy / Mori M.; L. Marini; E. Rampin; F. Zanetti; G. Mosca; N. Contaldo; A. Bertaccini. - STAMPA. - (2010), pp. 25-25. (Intervento presentato al convegno Current status and perspectives of phytoplasma disease research and management tenutosi a Sitges, Spain nel February 1st and 2nd, 2010).
First report of ‘Candidatus Phytoplasma asteris’ associated with several cultivars of oilseed rape in Italy
ZANETTI, FEDERICA;CONTALDO, NICOLETTA;BERTACCINI, ASSUNTA
2010
Abstract
In April and May 2009, phytoplasma symptoms were observed in several cultivars of oilseed rape (Brassica napus L. var. oleifera) growing in three trials located in the Experimental Farm of Padova University. The fields were established in October 2008 to test agronomic performance of different oilseed rape cultivars. Affected plants presented symptoms such as stunting, leaf reddening, green petals and extensive malformations of floral parts. When an inflorescence was affected only a small proportion of flowers set seeds at the end of the cycle. Among the 51 varieties cultivated in the fields 27 showed the described symptoms with a disease presence varying from 0.03 – 1.89% of the crop. Symptomatic samples from 6 plots of 5 varieties were collected and phytoplasma detection and identification was obtained with PCR assay using R16F2/R16R2 universal primers specific to the phytoplasma 16S rRNA gene (Lee et al., Phytopathology, 85, 728-735. 1995). PCR products of expected size (~1.2 kb) were obtained from all samples with symptoms but not from the 2 symptomless samples, collected as negative controls. RFLP analyses using TruI, BfaI, and HhaI restriction enzymes allowed to verify that amplicons from all positive samples showed identical profiles, undistinguishable from those of the European aster yellows phytoplasma (16SrI-B) reference strain. The results indicate that a ‘Ca. P. asteris’ related phytoplasma was associated with the disease. The same phytoplasma was already detected in winter oilseed rape in Czech Republic and, recently, in Greece (Bertaccini et al., Plant Pathology, 47, 317-324. 1998; Maliogka et al., Plant Pathology, 88, 792. 2009); therefore this new finding indicates some epidemic spreading of the disease. This is the first report of the association between ‘Ca. P. asteris’ and oilseed rape in Italy and studies to verify epidemiological behaviours of the disease in insect and weeds are in progress.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
