Distribution of ryegrass mosaic virus in New Zealand perennial ryegrass pastures as determined by ELISA and RT‐PCR

Abstract

Ryegrass mosaic virus (RgMV) is a mite-transmitted member of the Potyviridae that can seriously affect yield and persistence of ryegrass in pastures. To determine the incidence and distribution of RgMV in New Zealand, perennial ryegrass pastures were surveyed by indirect ELISA. RgMV was detected in all seven mature ( 4 years) North Island pastures and 60% of 20 mature South Island pastures, indicating that RgMV is established throughout New Zealand. A reverse transcriptasepolymerase chain reaction (RT-PCR) assay was developed to confirm the identity of RgMV. This assay was 200 times more sensitive than the indirect ELISA. A possible correlation between numbers of the eriophyid mites and the incidence of RgMV was observed in South Island pastures. Our results suggest that mite transmission may be more significant than ryegrass cultivar, pasture age, endophyte infection, or mechanical transmission in defining the incidence and distribution of RgMV. Options for the control of RgMV in New Zealand pastures are discussed.

Novel genus-specific broad range primers for the detection of furoviruses, hordeiviruses and rymoviruses and their application in field surveys in South-east Australia

“…A number of commercial tests using enzyme-linked immunosorbent assay (ELISA) and/or immunocapture polymerase chain reaction (IC-PCR) are available for the detection of viruses such as BSMV and RGMV (Ãy et al, 2008). Virus-specific reverse transcription polymerase chain reaction (RT-PCR) assays are also available for some members of these genera but not all (Chen et al, 1996;Salm et al, 1996;Webster et al, 1996;Diao et al, 1999;Clover et al, 2001;Koenig et al, 2002;Budge et al, 2008;Vaïanopoulos et al, 2009). RT-PCR assays utilising broad-range primers have been demonstrated to provide a faster tool for the detection of multiple viruses, and broad detection is also more likely to detect unreported species (Ha et al, 2008;Zheng et al, 2010).…”

Svidrės mozaikos viruso (<i>Ryegrass mosaic rymovirus</i>) nustatymas <i>Poaceae</i> šeimos augaluose

“…Investigation by the RT-PCR method was performed using two primers pairs selected for two different strains: Australian strain of RGMV (forward primer (RGMV-1)-GAACATGACTTCCACGACATCACCGACA-3'(28 nt); (reverse primer (RGMV-2) -5'-AGCAAGTAAGTGGGCAGACAG-3' (21 nt) [5] and for RgMV-Bulgaria and -Czech strains -RGMV-F1 5'-GCA CGC ACC ATA CCT AGC TG-3' (20 nt) and RGMV-R2: 5'-CAG CAT ATT CGC ACC CGA GA-3'(20 nt). A 1126-bp fragment from the coding region of the CP gene was sequenced from RgMVBulgaria and RgMV-Czech strains after PCR amplification with RgMV-F1 and RgMV-R2 primers [13].…”

“…DNA amplification was carried out in a reaction mixture containing dNTP mix, RGMV-1 and RGMV-2 primers (Australian strain) [5] and accordingly RgMV-F1 and RgMV-R2 (Bulgarian and Czech strain) primers [13]. PCR buffer with magnesium chloride and Taq DNA polymerase (MBI "Fermentas").…”

“…RGMV is transmitted by the eriophyid mite Abacarus hystrix (Nalepa) [8] and by mechanical inoculation [9], and is also thought to be spread mechanically by livestock treading and haycutting machinery [5].…”

“…RGMV is considered, after strains of barley yellow dwarf virus, the most serious and widespread virus affecting fodder grasses [4]. Studies indicate that infections with virulent RGMV strains may decrease the yield of pastures of Italian ryegrass by up to 27% and by 5 to 50% in perennial ryegrass [2,5].…”