Prunus necrotic ringspot virus. Coloured transmission electron micrograph (TEM) of virus particles (virions) of the prunus necrotic ringspot virus (PNRSV). This plant virus is an ilarvirus, and has an RNA (ribonucleic acid) genome. It was first identified in 1931 in the peach plant (Prunus persica), a plant cultivated for its fruit. This virus also infects rose and cucumber plants. Symptoms are brown streaks and rings. The virus is transmitted by pollen into the pollinated plant's seeds. It is found in North America and some European countries. Magnification: x125,000 when printed 10cm high.