First identification of Alstroemeria mosaic virus in Taiwan

Alstroemeria (Alstroemeria spp.; family Alstroemeriaceae) has gained interest all over the world in the last decade. Although these monocotyledonous plants originated from South American, most breeding has been conducted in the Netherlands. Alstroemeria has been multiplied vegetatively for many years and several viruses have been described from the crop, with Alstroemeria mosaic virus (AlsMV) being the most frequently reported (van Zaayen et al., 1994).

In 2004, mosaic symptoms were observed on leaves of alstroemeria plants (Fig. 1) growing in the north of Taiwan. Sap extracts from these diseased plants caused chlorotic lesions in mechanically inoculated leaves of Tetragonia expansa. After three successive single lesion isolations in T. expansa, a virus isolate was obtained. By indirect ELISA, both alstroemeria and T. expansa plants showing symptoms tested positive for potyviruses using an anti-potyvirus group monoclonal antibody (Agdia Inc., Elkhart, IN, USA). The presence of a potyvirus was also confirmed by RT-PCR, from total RNA, using a potyvirus-specific degenerate primer for the NIb gene and an oligo-dT primer (Huang & Chang, 2005). A 1.8-kb fragment was amplified and then cloned into pCR^®II-TOPO^® vector (Invitrogen, Carlsbad, CA, USA). Four independent clones were sequenced and a BLAST search performed against the NCBI database. The results revealed that the sequenced fragment (accession number DQ295032), containing the 3'-terminal region of AlsMV including partial NIb, complete CP and 3'UTR. It has 98% nucleotide identity with the only published partial sequence of AlsMV (Fuji et al., 2004; accession number AB158522), indicating that the virus obtained is an isolate of AlsMV. To our knowledge, this is the first identification of AlsMV from naturally infected alstroemeria in Taiwan.