Cucumber (Cucumis sativus L.) is widely cultivated in Italy in about 1.200 ha (ISTAT, 2008). In Veneto region it is grown in about 90 ha under screen mainly in Verona and Venezia provinces for fresh consumption. Different infectious pathogens are affecting cucumber, fungi: Erisiphe cichoracearum, Pseudoperonospora cubensis and Botrytis cinerea. Among pests: Frankliniella occidentalis, Aphis gossypii, Heliothis armigera, Udea ferrugalis, Liriomyza spp. and Tetranychus urticae are affecting cucumber. Cucumber mosaic virus (CMV), Tobacco Mosaic Virus (TMV) and Zucchini Yellow Mosaic Virus (ZYMV) are also severely affecting cucumber. During 2009 in Verona and Oppeno (Verona province) cucumber plants showing symptoms referred to possible phytoplasma presence were observed such as stunting and abnormal growth, distortion of leaves that have small size and chlorotic borders; a reduced number of malformed flowers were produced and fruits were stunted and malformed. In July samples were collected from symptomatic and asymptomatic plants and nucleic acid extraction using a chloroform/phenol method (Prince et al., 1993) was carried out from shoots, midribs and petioles. Phytoplasma identification was obtained with PCR using primers R16F2/R16R2 specific for phytoplasma 16S rRNA (Lee et al., 1995), followed by RFLP analyses with TruI, BfaI, and HhaI and by nested-PCR with primers R16(I)F1/R1 specific for some of the described phytoplasma ribosomal groups. In amplicons from symptomatic samples identical RFLP profiles were observed in all cucumber samples and these profiles were indistinguishable from the one of strain STOL (stolbur from pepper from Serbia, 16SrXII-A), employed as reference strain. To our knowledge this is the first report of stolbur in cucumber, however the same species was recently reported to be infected by 16SrII phytoplasmas in Iran when phyllody symptoms were present (Tazehkand et al., 2010). The plants studied were produced in different nurseries and belong to the ginoic cultivars Jazzer and Sargon. Disease incidence in field was of 4-6% randomly distributed in the infected plots. Further studies on phytoplasma characterization and on its epidemiological spreading in cucumber are in progress.
Grave infezione da fitoplasmi stolbur in cetriolo in Veneto / Pasini M.; N. Mori; L. D. Boscaini; S. Paltrinieri; N. Contaldo; A. Bertaccini. - In: PETRIA. - ISSN 1120-7698. - STAMPA. - 20(3):(2010), pp. 702-704. (Intervento presentato al convegno V Italian National Meeting on Phytoplasma Diseases tenutosi a Ancona Italy nel 21-23 settembre 2010).
Grave infezione da fitoplasmi stolbur in cetriolo in Veneto
PALTRINIERI, SAMANTA;CONTALDO, NICOLETTA;BERTACCINI, ASSUNTA
2010
Abstract
Cucumber (Cucumis sativus L.) is widely cultivated in Italy in about 1.200 ha (ISTAT, 2008). In Veneto region it is grown in about 90 ha under screen mainly in Verona and Venezia provinces for fresh consumption. Different infectious pathogens are affecting cucumber, fungi: Erisiphe cichoracearum, Pseudoperonospora cubensis and Botrytis cinerea. Among pests: Frankliniella occidentalis, Aphis gossypii, Heliothis armigera, Udea ferrugalis, Liriomyza spp. and Tetranychus urticae are affecting cucumber. Cucumber mosaic virus (CMV), Tobacco Mosaic Virus (TMV) and Zucchini Yellow Mosaic Virus (ZYMV) are also severely affecting cucumber. During 2009 in Verona and Oppeno (Verona province) cucumber plants showing symptoms referred to possible phytoplasma presence were observed such as stunting and abnormal growth, distortion of leaves that have small size and chlorotic borders; a reduced number of malformed flowers were produced and fruits were stunted and malformed. In July samples were collected from symptomatic and asymptomatic plants and nucleic acid extraction using a chloroform/phenol method (Prince et al., 1993) was carried out from shoots, midribs and petioles. Phytoplasma identification was obtained with PCR using primers R16F2/R16R2 specific for phytoplasma 16S rRNA (Lee et al., 1995), followed by RFLP analyses with TruI, BfaI, and HhaI and by nested-PCR with primers R16(I)F1/R1 specific for some of the described phytoplasma ribosomal groups. In amplicons from symptomatic samples identical RFLP profiles were observed in all cucumber samples and these profiles were indistinguishable from the one of strain STOL (stolbur from pepper from Serbia, 16SrXII-A), employed as reference strain. To our knowledge this is the first report of stolbur in cucumber, however the same species was recently reported to be infected by 16SrII phytoplasmas in Iran when phyllody symptoms were present (Tazehkand et al., 2010). The plants studied were produced in different nurseries and belong to the ginoic cultivars Jazzer and Sargon. Disease incidence in field was of 4-6% randomly distributed in the infected plots. Further studies on phytoplasma characterization and on its epidemiological spreading in cucumber are in progress.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
