Identificación y caracterización de Dasheen mosaic virus en cala (Zantedeschia aethiopica) en Córdoba, Argentina.

EVA E. CAFRUNE, ; FLORENCIA ASINARI, ; CLAUDIA F. NOME, ; MARÍA C. PEROTTO, ; MARIANA QUIROGA; VILMA C. CONCI

FITOPATOLOGÍA COLOMBIANA

FITOPATOLOGIA COLOMBIANA

Lugar: Bogotá; Año: 2012 vol. 35

0120-0143

The Araceae is a family of monocotyledonous plants, which includes food and ornamental species. This family of plants has 2950 species consisting in 106 genera. Among them, Zantedeschia is a type of greatcommercial importance. Agamic propagation of the species of this sort, carries the transmission of systemic pathogens such as viruses. Thus, the importance of a good diagnosis of mother plants for producing virus free material. Z. aethiopica (common Calla Lilies) is an worldwide ornamental plant, and viruses are one of the most important factors that limit its production. Numerous viruses infecting Calla Lilies have been cited, among which Tospovirus, Potyvirus, Carmovirus y Cucumovirus stand out. The aim of this work was to identify the causative organism of mosaic symptoms in Z. aethiopica in gardens of Cordoba city, Argentina. Tubular flexuous virus particles were observed in transmission electron microscope using the method of "leaf dip". In ultrathin sections of symptomatic leaves showed the presence of cylindrical inclusions, typical of Potyvirus. We confirmed the presence of this genus by indirect enzyme immunoassay technique (PTA-ELISA) using antiserum for Potyvirus (BIOREBA). A genomic fragment of 664 nt corresponding to the final portion of the Nib gene and the first part of the capsid protein (CP) was cloned and sequenced, resulting among 70.2% to 87.3% identity of amino acids with the Dash mosaic virus (DSMV). In order to confirm the identity of the virus, specific primers for DSMV CP was used, and a fragmnt of 1000 bp was obteined. The fragment was cloned, sequenced and the resulting sequence was compared with published sequences in GenBank. An homology of 83.6 and 95.2% with other sequences CP DSMV was established, and the highest identity was with DSMV in Zantedeschia sp. (94.3 to 95.2%). This confirms the identity of the pathogen according to the ICTV species demarcation criteria for Potyvirus (greater than 80% homology of amino acids in the CP). It was also demontrated a high identity with three published sequences as VanMV (81.4 to 94.5%) and one Spathiphyllum potyvirus (81.1%), species within the genus Potyvirus. This could indicate that the sequences published as Spathiphyllum potyvirus and VanMV could be the same virus. Phylogenetic analysis of the 29 sequences showed two large groups, or clusters, separated with a high value of "bootstrap" (98.1%). Clusters containing DSMV revealed differences that might allow to sepate it into strains of the virus, this problem should be studied in the future.