Maize dwarf mosaic virus (MDMV) is a serious and widespread virus pathogen of maize plants. This +ssRNA virus belongs to the Potyvirus genus in the Potyviridae family. Together with sugarcane mosaic virus (SCMV) it causes one of the most important viral diseases on maize crops in the world – maize dwarf mosaic. Both viruses are transmitted in the same non-persistent manner by several aphid species. They induce similar symptoms of leaf mosaic or mottling, stunting and a reduction in plant weight and grain yield. Available MDMV diagnostics include primarily commercialized enzyme-linked immunosorbent assays (ELISA) and reverse transcription-polymerase chain reactions (RT-PCR). Here, laborsaving reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay was optimized for identification of genetically different MDMV isolates. For this purpose, primer sets, MDMVF3/MDMVB3 and MDMVFIP/MDMVBIP amplifying fragments of coat protein coding sequence of MDMV, were used. The specificity of the reaction was verified using three MDMV (-P1, -Sp, -PV0802-DSMZ) and three SCMV (-P1, -PV0368- -DSMZ, -PV1207-DSMZ) isolates. Obtained products were visualised by DNA staining, electrophoretic separation as well as by real-time monitoring of the reaction. The sensitivity of RT-LAMP and conventional RT-PCR reactions was comparable. Both methods could detect virus as low as 550 fg · μl–1 of total RNA. This technique has application value for screening MDMV by phytosanitary services.

Dasheen mosaic virus (DsMV) is one of the most important viral pathogens of aroids and can cause major economic losses for ornamental crops. Here, we present the detection and molecular characterisation of DsMV isolates originating from Monstera adansonii plants in Poland. Moreover, the genetic variability of DsMV isolates was analyzed based on the coat protein gene ( CP) of the Polish and other DsMV isolates described to date. The presence of DsMV was confirmed by transmission electron microscopy (TEM) and reverse transcription polymerase chain reaction (RT-PCR) with specific, diagnostic primers in three out of ten examined plants. To obtain full-length sequences of CP, two pairs of primers were designed and used in the RT-PCR. The specificity of obtained products was confirmed by Sanger sequencing. The obtained sequences of CP were compared with 44 other DsMV sequences retrieved from the GenBank. Analyses revealed that DsMV population is very diverse. The variability of DsMV isolates was confirmed by low sequence identity and pervasive recombination events. The phylogenetic analysis was performed based on 37 non-recombinant CP sequences. The maximum-likelihood reconstruction revealed that the Polish isolates are distinct and grouped separately from other DsMV isolates. Due to the high genetic diversity, detecting the virus could be difficult. Nonetheless disease management relies strongly on a fast and accurate identification of the causal agent. To our knowledge this is the first report of DsMV in Poland.