Archivio Journal of Plant Pathology

Abstract:

Cabbage (Brassica oleracea var. capitata) is one of the most im- portant vegetable crops in Greece grown on an area of 7,006 ha with a production of 188,000 tons (FAOSTAT, 2009). During a survey conducted on winter 2009 in northern Greece for pathogens infecting plant species of the Brassicaceae family, two cabbage plants showing phytoplasma-like symptoms were collect- ed near the village of Vasilika-Thessaloniki (40o28’N 23o08’E). These plants exhibited reduction of leaf size (little leaf), opening of the head, proliferation and generalized stunting. In order to in- vestigate the possibility of a phytoplasma infection, DNA was ex- tracted from leaf samples of two symptomatic and two apparently healthy plants according to the in house protocol developed by Psifidi et al. (2010). A nested PCR was done using two universal primer sets specific to the phytoplasma 16S rRNA gene: P1/P7 (Schneider et al., 1995) followed by R16F2n/R16R2 (Gundersen and Lee, 1996). The expected ca. 1200 bp amplicon was obtained from both symptomatic cabbage plants but not from the symp- tomless ones. One of the two amplicons was purified and directly sequenced. BLAST comparisons of the partial 16S rRNA se- quence revealed 99% identity with the homologous sequence from Ca. Phytoplasma asteris reference strain (M30790). The ob- tained sequence was deposited in EMBL-EBI database (accession No. HE601634). In silico RFLP analysis (Zhao et al., 2009) classi- fied the isolate in the 16SrI-B subgroup. Ca. Phytoplama asteris is an important pathogen of many herbaceous and woody plants; it has a worldwide distribution and has been previously associated with various diseases of several Brassicaceae plant species. How- ever this is, to our knowledge, the first record of a cabbage dis- ease associated with Ca. Phytoplasma asteris in Greece.