A novel negative-sense, single-stranded RNA virus in a mallow plant showing mosaic symptoms was identified through high-throughput sequencing, and its presence was confirmed by conventional Sanger sequencing of RT-PCR products. The virus was provisionally named malva-associated emaravirus 1 (MaV1). MaV1 had a genome comprising four genomic RNA segments, each containing a single ORF on the complementary strand and two untranslated regions with complementary 13-nt stretches at the 5′ and 3′ terminal ends. The segmented RNA genome of the MaV1 displayed a genome organization typical for emaraviruses, encoding the viral RNA-dependent RNA polymerase (RdRp, 270.71 kDa) on RNA1 (7,009 nt), a glycoprotein precursor (GP, 73.37 kDa) on RNA2 (2,105 nt), a nucleocapsid protein (NP, 33.43 kDa) on RNA3 (1,265 nt), and a nonstructural movement protein (MP, 42.32 kDa) on RNA4 (1,472 nt). Compared to established species of the genus Emaravirus, the putative proteins encoded by MaV1 showed the highest aa sequence identity with those of jujube yellow mottleassociated virus (JYMaV), raspberry leaf blotch virus (RLBV), and Arceuthobium sichuanense-associated virus 1 (ArSaV1): 63.3%, 61.6%, and 61.1% in RdRp; 44.8%, 49.2%, and 49.9% in GP; 51.4%, 53.3%, and 48.6% in NP; and 59.9%, 58.2%, and 58.3% in MP, respectively. These values are significantly below the current species demarcation threshold (< 80%) for the genus Emaravirus, indicating that MaV1 represents a new species within this genus. Phylogenetic trees constructed based on aa sequences of putative proteins placed MaV1 in a separate clade, along with RLBV, JYMaV, and ArSaV1. This is, to our knowledge, the first report of the natural occurrence of an emaravirus from mallow worldwide.

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