First report of <i>Maize striate mosaic virus</i>, a mastrevirus infecting <i>Zea mays</i> in Argentina

During 2021, sweet corn plants cultivated for human consumption in a 400-ha area Santa Fe province, Argentina, showed severe virus-like symptoms, including marked dwarfism, plant deformation, nerval or internerval vein yellowing, chlorotic rings, chlorosis along leaf edges, and thickening (Figure 1, 2). Abundant populations of the leafhopper Dalbulus maidis, vector several pathogens (Carloni et al., 2013), were also observed 3). Ten diseased collected Helvecia, (31°07´47´´S, 60°08´48´´W) tested by dip serology (DAS-ELISA PTA-ELISA) against: Maize yellow striate virus, Mal de Río Cuarto Spiroplasma kunkelii, Sugarcane mosaic virus (JM isolate) (IPAVE, Córdoba, Argentina), rayado fino (MRFV) (provided Castillo Loayza, UNALM, Perú), mottle (MCMV), dwarf (BIOREBA, Switzerland), Wheat streak (DSMZ, Germany), Cucumber High Plains wheat (HPWMoV), (MSV) (SCMV) (Agdia, USA). The samples positive one more following pathogens: HPWMoV, MCMV, MRFV, SCMV S. six them had mild reaction when MSV (Table 1). Furthermore, electron microscopy detected geminivirus-like particles sample 4, with 4). DNA this was extracted using CTAB method, amplified rolling circle amplification (Inoue-Nagata 2004) sequenced MinION Mk1B device Rapid Barcoding kit (Oxford Nanopore Technologies, UK). Raw sequences filtered Filtlong (https://github.com/rrwick/Filtlong) software, assembled minimap2/miniasm (https://github.com/lh3/minimap2). Contigs (MSMV) identified BLASTn against local viral reference database available from NCBI polished Medaka v1.2.3 (https://github.com/nanoporetech/medaka). MSMV has 96.6% amino acid identity coat protein MSV, hence cross-reaction ELISA. Thirty-seven sequences, dicot- monocot-infecting species, aligned MAFTT, maximum-likelihood phylogenetic tree constructed IQ-TREE (http://www.iqtree.org/) 1000 bootstrap replications. sequence Argentinian isolate (GenBank Accession No. OP811251) 2746 bp, shares 99% all previously described isolates, final that branches representative 5) first maize sugarcane Brazil (Fontenele 2018, Batista 2021). high population levels effects on growth yield susceptible cultivars (Vilanova 2022) warrant further epidemiological studies to assess importance pathogen Argentina. To our knowledge, is report (Mastrevirus, Geminiviridae) infecting Zea mays This work supported Project INTA-PD-I090, PUE 229-2018-01-64CO. A. Ruiz Posse hold scholarship CONICET-INTA