Genealogy of Cucumber mosaic virus Isolated from Ornamental Species

摘要

Cucumber mosaic virus (CMV) has the broadest host range, infecting more than 1300 species in more than 500 genera from over 100 botanical families. In ornamental plants, CMV can cause mosaic and distortion of leaves, stunting, color break, and malformation of flowers. CMV coat protein (CP) sequences obtained from seven ornamental plants and other homologous sequences available in GenBank were compared, and phylogenetic relationships were established. Total RNA from virus-infected ornamental species were extracted, submitted to RT-PCR with specific primers, and amplicons obtained were sequenced. A nucleotide substitution model and phylogenetic analyses were carried out using the PAUP program. The seven sequences of CMV CP obtained showed similar identity percentages and close relationships with subgroup I isolates from other countries and hosts. CMV isolates from different regions of S?o Paulo state, Brazil (Salvia splendens, Catharanthus roseus, Nematanthus nervosus (=Hypocyrta nervosa), Impatiens walleriana, Eucharis grandiflora and Commelina sp.) formed a monophyletic group, indicating a possible common origin. It was found that when lily sequences of CMV only from different geographic regions were compared, Brazilian isolates shared the same common ancestor with those from Poland and Taiwan. Furthermore, this monophyletic group presented a quite basal position.