Plantago asiatica mosaic virus Found in Protected Crops of Lily Hybrids in Southern Italy

Abstract

HomePlant DiseaseVol. 99, No. 9Plantago asiatica mosaic virus Found in Protected Crops of Lily Hybrids in Southern Italy PreviousNext DISEASE NOTES OPENOpen Access licensePlantago asiatica mosaic virus Found in Protected Crops of Lily Hybrids in Southern ItalyG. Parrella, B. Greco, A. Pasqualini, and A. G. NappoG. ParrellaSearch for more papers by this author, B. GrecoSearch for more papers by this author, A. PasqualiniSearch for more papers by this author, and A. G. NappoSearch for more papers by this authorAffiliationsAuthors and Affiliations G. Parrella B. Greco A. Pasqualini A. G. Nappo , Istituto per la Protezione Sostenibile delle Piante del CNR, UOS di Portici, 80055 Portici (NA), Italy. Published Online:6 Jul 2015https://doi.org/10.1094/PDIS-03-15-0281-PDNAboutSections ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat In the winter of 2013 and 2014, severe necrotic streaking in midstem leaves were observed on plants of lily hybrids (Lilium sp., family Liliaceae) in several greenhouses of the Campania region (southern Italy). A total of 14 symptomatic plants (seven in 2013 and seven in 2014) were chosen to complete diagnostic tests in the laboratory: four plants of Asiatic hybrid (unknown variety), seven of LA hybrid (L. longiflorum × Asiatic hybrid) of cv. Brindisi and three of Oriental hybrids (two of cv. Santander and one of cv. Pandora). Leaf samples were tested for the presence of potyviruses by indirect ELISA using the “poty group test” kit (Bioreba, Switzerland) and by double-antibody sandwich (DAS)-ELISA with Plantago asiatica mosaic virus (PlAMV; genus Potexvirus, family Flexiviridae) specific antibody and conjugate (kindly provided by Dr. de Kock, BKD, Flowerbulb Inspection Service, The Netherlands). All samples tested negative to the poty group antiserum, while PlAMV specific antibody detected the virus in all samples of Asiatic and Oriental lilies and three out of seven of the LA hybrids. Mechanical inoculation of leaf samples, pooled per typology of hybrids, elicited systemic mosaic followed by streaking and apical necrosis in N. benthamiana, and chlorotic/necrotic local lesions in C. quinoa. The presence of PlAMV was confirmed by testing in ELISA the symptomatic leaves of both host plants. Molecular detection of PlAMV was performed by reverse transcription-polymerase chain reaction (RT-PCR), using the primer pair PLMCPfw (5′-GGAGGCCGVTACGTCGACGG-3′) and PLMCPrev (5′-AAACGGTAAAATACACACCGGG-3′) on total RNA extracted from symptomatic leaves of each plant. These primers were designed based on multialignment of all PlAMV sequences available in GenBank and in order to amplify a fragment of approximately 1.0-kb encompassing the complete ORF of the coat protein. After RT-PCR, the 1.0-kb amplicon was obtained in all samples of Asiatic and Oriental hybrids and in three out of seven samples of the LA hybrid, the same found positive in ELISA. The identity of the virus was further confirmed by sequencing seven out of 10 amplicons obtained (one from the Asiatic hybrid from unknown variety, GenBank Accession No. LN827657; three from Oriental hybrids cvs Pandora and Santander, LN827658 and LN827659-60, respectively; three form the LA hybrid cv. Brindisi, LN651192-94). All the sequences showed the highest nucleotide sequence identity with the Dutch isolate Sorbonne of PlAMV (KF471012), ranging from 99.4 to 99.8%. This is the first report of PlAMV in Lilium spp. in Italy. Severe leaf necrosis syndrome caused by PlAMV in Lilium spp. was described in 2010 in The Netherlands (EPPO Reporting Service 2011), probably introduced with infected Asian germplasm of Lilium spp. (Anderson 2012). PlAMV infections were then reported in 2012 in UK in Lilium spp. introduced from Spain (Anderson 2012) and recently in the United States in Asiatic and Oriental lilies imported from the Netherlands (Hammond 2015). Based on sequences similarity of PlAMV isolates detected in Italy with the Dutch isolate (KF471012), also in this case the accidental introduction of infected bulbs from the Netherlands is strongly suspected. PlAMV could become a significant pathogen in protected lily crops based upon its capacity to be transmitted by contact, and thus this further discovery would suggest that more efficient diagnostic methods for PlAMV detection, within an accurate certification scheme of lily bulbs production, should be adopted.