First report of bean common mosaic virus infecting flowering ginger (Alpinia purpurata) in Hawai'i

Authors: LARREA-SARMIENTO, A - University Of Hawaii; WANG, X - University Of Hawaii; BORTH, WAYNE - University Of Hawaii; BARONE, R - University Of Hawaii; OLMEDO-VERLARDE, A - University Of Hawaii; MELZER, MICHAEL - University Of Hawaii; SUGANO, J.S.K - University Of Hawaii; GALANTI, R - University Of Hawaii; Suzuki, Jon; Wall, Marisa; HU, JOHN - University Of Hawaii

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/17/2019
Publication Date: 11/19/2019
Citation: Larrea-Sarmiento, A., Wang, X., Borth, W.B., Barone, R., Olmedo-Verlarde, A., Melzer, M.J., Sugano, J., Galanti, R., Suzuki, J.Y., Wall, M.M., Hu, J.S. 2019. First report of bean common mosaic virus infecting flowering ginger (Alpinia purpurata) in Hawai'i. Plant Disease. 104(2):63. https://doi.org/10.1094/PDIS-06-19-1264-PDN.
DOI: https://doi.org/10.1094/PDIS-06-19-1264-PDN

Interpretive Summary: Flowering ginger (Alpinia purpurata) is an important ornamental crop in Hawai'i that has been previously shown to harbor single or simultaneous infections by the plant viruses, canna yellow mottle virus (CaYMV) and a non-related virus known as banana bract mosaic virus (BBrMV). Plants infected with both CaYMV and BBrMV show viral-like symptoms that include mosaic and streaking. In March of 2019, flowering ginger plants with virus-like symptoms distinct from those of CaYMV and BBrMV mixed infections including green mosaic patterns along leaf veins, stunted growth, and chlorosis were observed on O'ahu, Hawai'i. DNA sequence analysis of viral sequences obtained from the corresponding diseased plant tissue samples indicated the presence of canna yellow mottle virus (CaYMV). However, instead of BBrMV, a virus known as bean common mosaic virus (BCMV ) different from but related to BBrMV was found alongside CaYMV in the diseased flowering ginger tissue. This is the first report of BCMV and CaYMV identified together in flowering ginger. Molecular methods to detect and distinguish BCMV from other plant viruses were developed in this study in order to help monitor prevalence of this virus in the field. Additional research is needed to determine whether BCMV is contributing to the current severe die-back disease or to another disease threatening the flowering ginger industry in Hawai'i.

Technical Abstract: Flowering ginger (Alpinia purpurata) is an important ornamental crop in Hawai'i that has been previously shown to harbor single and mixed infections by the potyvirus banana bract mosaic virus (BBrMV) and the badnavirus canna yellow mottle virus (CaYMV). In March 2019, flowering ginger plants with virus-like symptoms including green mosaic patterns along leaf veins, plant stuntedness, and chlorosis that were distinct from the mosaic and streaking symptoms produced by dual infections of BBrMV and CaYMV were observed on O'ahu, Hawai'i. Symptomatic leaf samples from two plants were assayed for the presence of potyviral and badnaviral infection by PCR using genus-specific primer sets. All symptomatic samples were found to be infected by CaYMV, but BBrMV was not detected. Instead, sequence of amplicons obtained from PCR using the potyviral-specific primers (MN073501) showed 97% identity by Blastn analysis to the BCMV clone zz1 (KM878928), infecting sesame (Sesamum indicum) in China. Interestingly, the new BCMV strain in A. purpurata shared only 93.8% identity to BCMV strain A1 (MK282414), a new strain of BCMV characterized previously from lima bean in Hawaii. BCMV is a viral species of the genus Potyvirus in the family Potyviridae that is transmitted mechanically and in a non-persistent manner by several species of aphids. A primer set designed to amplify a 376 bp amplicon based on the cylindrical inclusion (CI) protein of BCMV was developed to specifically detect BCMV from among other viruses by PCR. Ginger infected with BCMV could also be detected using potyvirus genus-specific ELISA as well as BCMV-specific ELISA. To our knowledge, this is the first report of BCMV naturally infecting flowering ginger. Additional research is needed to determine whether its presence is contributing to the current severe die-back disease or to another disease threatening the flowering ginger industry in Hawai'i