A distinct lineage of Watermelon mosaic virus naturally infects honohono orchid (Dendrobium anosmum) and passionfruit (Passiflora edulis) in Hawaii

摘要

An orchid nursery in Honolulu, Hawaii reported honohono orchids (Dendrobium anosmum cv. Little Sweet Scent) with deformed flowers displaying colour break (Fig. 1) and mild chlorotic streaking of the leaves (Fig. 2). Eight orchid plants displaying these symptoms were assayed for dendrobium mosaic virus, a strain of the Bean common mosaic virus group of potyviruses that has been previously detected in Hawaii’s honohono orchids (Hu et al., 1995). A potyvirus group ACP-ELISA was performed following the manufacturer’s directions (Agdia Inc., Elkhart, USA), and indicated the presence of a potyvirus in these orchids. RNA was extracted from the plants using an RNeasy? Plant Mini Kit (Qiagen Inc., Valencia, USA) and universal potyvirus RT-PCR was performed (Zheng et al., 2010) which confirmed the presence of a potyvirus in these samples. Amplification products were cloned into pGEM?-T Easy (Promega Corp., Madison, USA) and three clones from each of five of the samples were sequenced at the University of Hawaii’s Advanced Sequence Genomics Proteomics and Bioinformatics laboratory. All sequences had highest sequence similarity to Watermelon mosaic virus (WMV). Using the extracted RNA as template, the complete genome of WMV was amplified and sequenced using overlapping conserved primers (Table 1) and molecular cloning as described above. The sequence was deposited into GenBank (Accession No. HQ384216).