Characterization of a new curtovirus, pepper yellow dwarf virus, from chile pepper and distribution in weed hosts in New Mexico

Abstract

Over 4,950 asymptomatic weed samples from more than 20 weed species that are host plants for curtoviruses were collected from ten chile pepper fields in southern New Mexico (NM) during 2003, 2004 and 2005 to identify whether they were infected with curtoviruses and to determine which curtoviruses were distributed in the weed population. Polymerase chain reaction using primers designed to detect a portion of the coat protein (cp) gene were used to detect curtoviruses, and infected plants were further tested for specific curtoviruses using primers designed to detect to a portion of the replication-associated protein (rep) gene. Amplification of the cp gene was successful from 3.7, 1.17, and 1.9% of the weed samples in 2003, 2004, and 2005, respectively. Seventy-three amplicons from those samples were sequenced and compared to well-characterized curtoviruses. Analysis of the rep nucleotide sequences showed that ~32.9% of the weed isolates tested were closely related to beet mild curly top virus (BMCTV). Approximately 12.4% were closely related to beet severe curly top virus (BSCTV). The rest of the weed isolates (54.7%), which shared a very high level of nucleotide sequence identity to each other, represent a new curtovirus species. Using eight primers designed for PCR, complete genomes of three curtoviruses isolated from chile pepper samples representing the three groups of curtoviruses in southern New Mexico were sequenced. Comparisons of whole sequences of the genomes revealed that the DG2SW171601 isolate (2,929 nucleotides) was nearly identical to BMCTV-W4 (~98% nucleotide sequence identity). The LRME27601 isolate (2,927 nucleotides) was most closely related to BSCTV (~92% nucleotide sequence identity). The LJN17601 isolate (2,959 nucleotides) shared only from 49.9 to 88.8% nucleotide sequence identity with other well-characterized curtoviruses. Based on the accepted cut-off of 89%, we propose that the LJN17601 isolate is a member of a new curtovirus species. Chile peppers infected with this virus in the field express chlorotic stunting symptoms, so we propose the name pepper yellow dwarf virus (PeYDV). This new curtovirus species may be the result of mutations in the genome and recombination between BMCTV-W4 and BSCTV.

Characterization of Curtoviruses Associated with Curly Top Disease of Tomato in California and Monitoring for These Viruses in Beet Leafhoppers

“…Subsequent molecular studies confirmed genetic diversity among curly top viruses, and revealed that three distinct curtovirus species are associated with curly top in the western United States: Beet curly top virus (BCTV, the type strain and previously the Cal/Logan strain of BCTV), Beet mild curly top virus (BMCTV, previously the Worland strain of BCTV), and Beet severe curly top virus (BSCTV, previously the CFH strain of BCTV) (6,33,34,36,37,39). Additional curtovirus species include Horseradish curly top virus (20), Spinach curly top virus (2), and Pepper yellow dwarf virus (21).…”

Management of Severe Curly Top in Sugar Beet with Insecticides

“…However, the number of Curtovirus spp. or proposed species has increased in recent years and some have been shown to occur on sugar beet in other countries (5,7,14,15,19,39). Finding more than one of the Curtovirus spp.…”

Detection of Viral and Viroid Plant Pathogens in the Environment

“…The remaining isolates (54.7%) which shared a very high level of nucleotide sequence identity to each other, represent a new curtovirus. The new virus was identified as Pepper yellow dwarf virus (PeYDV) which might have resulted due to mutations in the genome and recombination between BMCTV-W4 and BSCTV (Lam et al 2009). …”