F. Villanueva, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora” (IHSM-UMA-CSIC), Consejo Superior de Investigaciones Científicas, 29750 Algarrobo-Costa, Málaga, Spain;
P. Castillo, Unidad de Virología, Laboratorio de Producción y Sanidad Vegetal de Almería, Agencia de Gestión Agraria y Pesquera de Andalucía, Consejería de Agricultura, Pesca y Medio Ambiente, Autovía del Mediterráneo salida 420, 04745 La Mojonera, Almería, Spain;
M. I. Font and
A. Alfaro-Fernández, Grupo Virología Vegetal, Instituto Agroforestal Mediterráneo, Universidad Politécnica de Valencia, Cno. Vera s/n, 46022 Valencia, Spain; and
E. Moriones and
J. Navas-Castillo, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora” (IHSM-UMA-CSIC), Consejo Superior de Investigaciones Científicas, 29750 Algarrobo-Costa, Málaga, Spain
In November 2012, unusual symptoms were observed in plants of sweet pepper (Capsicum annuum L.) grown in commercial greenhouses of Almería Province, southeastern Spain. Symptoms included interveinal yellowing, upward leaf curling, and internode shortening, and were more evident in the upper part of the plant. Abnormal ripening of fruits was observed in symptomatic plants, with fruits remaining orange in the red varieties and yellow in the orange varieties, thus reducing their marketability. During December 2012 and January 2013, severe outbreaks of this disease syndrome occurred, with many greenhouses exhibiting almost 100% incidence. The symptoms observed were similar to those reported for isolates of Pepper vein yellows virus (PeVYV, genus Polerovirus, family Luteoviridae) (previously also named Pepper yellow leaf curl virus [PYLCV] and Pepper yellows virus [PYV]) (2,4). Twenty five symptomatic leaf and/or fruit samples (some of them supplied by Zeraim Ibérica, S.A.), each from a different greenhouse, were analyzed and all reacted positively in double-antibody sandwich-ELISA with an antiserum against the polerovirus Cucurbit aphid-borne yellows virus (CABYV) (Sediag, Longvic, France), known to cross-react with PeVYV (2). Total RNA was extracted by TRIsure reagent (Bioline, London, United Kingdom) from symptomatic leaves and analyzed by reverse transcription (RT)-PCR with primers Pol-G-F (5′-GAYTGCTCYGGYTTYGACTGGAG-3′) and Pol-G-R (5′-GATYTTATAYTCATGGTAGGCCTTGAG-3′) designed for universal detection of poleroviruses by amplifying the RNA-dependent RNA polymerase (RdRp) and coat protein (CP) partial genes (3). DNA fragments of the expected size (1.1 kbp) were amplified supporting a polerovirus infection in all the analyzed samples. The PCR product obtained from one sample (Almería-1) was extracted from agarose gel with a QIAquick gel extraction kit (Qiagen, Hilden, Germany), cloned in pGEM-T Easy vector (Promega, Madison, WI), and one clone was sequenced (Macrogen Inc., Seoul, South Korea). The PCR products amplified from three other samples (2-13, 7-13, and 8-13) were directly sequenced. The nucleotide identity between the amplified fragments (GenBank Accession Nos. KC769487, KC839992 to 94), calculated after alignment with ClustalW, was 99.7 to 100%. The highest nucleotide identity of the Spanish sequences was with a PeVYV isolate from Turkey (FN600344, named as PYV) (98.5 to 98.7%). The spread of PeVYV in Spain is additional evidence of the emergence of this virus as a global threat for pepper crops after its first detection in Japan in 1995 and recent reports from the Mediterranean Basin (1,2).
References: (1) N. Buzkan et al. Arch. Virol. 158:881, 2013. (2) A. Dombrovsky et al. Phytoparasitica 38:477, 2010. (3) D. Knierim et al. Plant Pathol. 59:991, 2010. (4) R. Murakami et al. Arch. Virol. 156:921, 2011.