Characterization of two novel viruses within a complex virome from flowering ginger in Hawaii

Authors: LARREA-SARMIENTO, ADRIANA - University Of Hawaii; GALANTI, RUSSELL - University Of Hawaii; OLMEDO-VELARDE, ALEJANDRO - University Of Hawaii; WANG, XUPENG - University Of Hawaii; AL RWAHNIH, MAHER - University Of California, Davis; BORTH, WAYNE - University Of Hawaii; LUTGEN, HANNAH - University Of Hawaii; FITCH, MAUREEN - Hawaii Agricultural Research Center; SUGANO, JARI - University Of Hawaii; SEWAKE, KELVIN - University Of Hawaii; Suzuki, Jon; Wall, Marisa; MELZER, MICHAEL - University Of Hawaii; HU, JOHN - University Of Hawaii

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/21/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Flowering ginger (Alpinia purpurata) holds economic and cultural importance in Hawaii, contributing to a horticultural and nursery industry estimated at $81.6 million. In various areas where flowering ginger is grown, a slow decline in vigor has been observed in some plants. Modern sequencing methods was employed to investigate whether plant viruses were associated with this decline. Six plant viruses were found in ginger samples of which the presence of three, canna yellow mottle virus (CaYMV) and two new plant viruses, Alpinia vein clearing virus (ApVCV) and Alpinia vein streaking virus (ApVSV) were correlated with the slow decline syndrome. Further research revealed that the first two viruses are transmitted via a type of mealy bug, whereas the third is transmitted via a type of aphid. Results from this study identifies specific plant viruses associated with the symptom of ginger decline and their modes of distribution.This information is important for developing detection and management strategies for this disease.

Technical Abstract: Flowering ginger (Alpinia purpurata) is of economic and cultural importance in Hawaii. The association between viral infection and slow decline syndrome observed in flowering ginger in Hawaii was investigated using RNA-seq analyses and virus indexing surveys on plants from four of the Hawaiian Islands. Viral sequences corresponding to six viruses were recovered by RNA-seq data analysis from samples with virus-like symptoms. Canna yellow mottle virus (CaYMV, genus Badnavirus), and two novel viruses, Alpinia vein clearing virus (ApVCV, genus Ampelovirus), and Alpinia vein streaking virus (ApVSV, genus betanucleorhabdovirus), were associated with the slow decline syndrome. Conversely, three other viruses including the two potyviruses, banana bract mosaic virus (BBrMV) and bean common mosaic virus (BCMV), and the badnavirus, banana streak GF virus (BSGFV), were also found but at a low incidence, and their presence was not associated with the observed slow decline symptoms. Through virus detection from potential vectors and transmission assays, the mealybug Planococcus citri was identified as a vector of the semi-persistently transmitted CaYMV and ApVCV, while the aphid Pentalonia caladii was identified as a vector of the novel ApVSV. Both P. citri and P. caladii are common pests of flowering ginger in Hawaii. Transmission of ApVSV was achieved using P. caladii colonies naturally feeding on infected flowering ginger plants, although no transmission was obtained using viruliferous aphids originally reared on taro. Our study provides insights into the potential association between viral infections and the observed decline of flowering ginger in Hawaii.