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POSTERS: Pathogen detection, quantification and diagnosis

Identification of a novel endornavirus in Geranium carolinianum and occurrence in plants within three agroecosystems
Rodrigo Valverde - Louisiana State University Agricultural Center. Ricardo Alcala-Briseno- University of Florida, Eliezer Rodrigues De Souto- Universidade Estadual de Maringa, Ryo Okada- Tokyo University of Agriculture and Technology, Rachel Herschlag- Pennsylvania State University

Plant endornaviruses do not cause visible symptoms and are transmitted only vertically. In the spring of 2015, a putative endornavirus was detected in Carolina geranium (Geranium carolinianum) in Louisiana, USA. The virus was provisionally named Geranium carolinianum endornavirus 1 (GcEV1). With the objective of characterizing the virus, we sequenced the viral RNA using Illumina MySeq and reads were assembled with Spades 3.8.0. The viral genome consisted of 14,625 nt containing a single ORF coding for a putative polyprotein of 4,815 aa with conserved domains for a helicase­_1, peptidase_C97, UDP-glucoronosyl and UDP-glucosyl transferase, and RNA-dependent RNA polymerase (RdRP)_2. The 5’end consisted of 130 nt while the 3’end of 54 nt ending in nine cytosine residues. The closest relative to GcEV1 was Phaseolus vulgaris endornavirus 3, a putative endornavirus from common bean. In phylogenetic analyses using the RdRP, both endornaviruses formed a distinct cluster. GcEV1 was detected in 181 of 184 G. carolinianum plants collected from three distinct agroecosystems. The virus was not detected in seven other species of the genus Geranium. There was no correlation of a particular phenotypic trait of the host with the presence of the virus. GcEV1 was transmitted at a rate of 100% in seeds of a self-pollinated G. carolinianum plant. At the present time, the type of symbiotic interaction between GcEV1 and G. carolinianum is not known.