Molecular Characterization and Distribution of Two Strains of Dasheen mosaic virus on Taro in Hawaii

Abstract

Dasheen mosaic virus (DsMV) is one of the major viruses affecting taro (Colocasia esculenta) production worldwide. Whole genome sequences were determined for two DsMV strains, Hawaii Strain I (KY242358) and Hawaii Strain II (KY242359), from taro in Hawaii. They represent the first full-length coding sequences of DsMV reported from the United States. Hawaii Strains I and II were 77 and 85% identical, respectively, with other completely sequenced DsMV isolates. Hawaii Strain I was most closely related to vanilla mosaic virus (VanMV) (KX505964.1), a strain of DsMV infecting vanilla in the southern Pacific Islands. Hawaii Strain II was most closely related to a taro DsMV isolate CTCRI-II-14 (KT026108.1) from India. Phylogenetic analysis of all available DsMV isolates based on amino acid sequences of their coat protein showed some correlation between host plant and genetic diversity. Analyses of DsMV genome sequences detected three recombinants from China and India among the six isolates with known complete genome sequences. The DsMV strain NC003537.1 from China is a recombinant of KJ786965.1 from India and Hawaii Strain II. Another DsMV strain KT026108.1 is a recombinant of Hawaii Strain II and NC003537.1 from China. The third DsMV strain KJ786965.1 from India is a recombinant of Hawaii Strain II and NC003537.1 from China. To our knowledge, this is the first report of recombination events in DsMV. Both Hawaii Strains I and II of DsMV were found widespread throughout the Hawaiian islands.