Analyses of thrips vector and plant viromes in peanut pathosystem reveal orthotospovirus transmission networks

Thrips (Thysanoptera: Thripidae) are important vectors of viruses in peanut and cause direct feeding damage and indirectly transmit orthotospoviruses. The important thrips species that transmit orthotospoviruses in south eastern United States are Frankliniella fusca (Hinds) and F. occidentalis (Pergande). Thrips also feed on weed species in the spring before peanut planting, spanning various plant families, including Amaranthaceae, Asteraceae, Brassicaceae,Caryophyllaceae, Fabaceae, Malvaceae, Poaceae, Polygonaceae, and Solanaceae that act as reservoirs of plant viruses. The status of viruses acquired by thrips from weed species and transmitted to peanuts is not clear. To understand this, we carried out virome analyses of thrips collected from weed species and sticky traps and plants in peanut pathosystem from 13 locations spanning six counties in South Georgia: Tift, Irwin, Ben Hill, Turner, Colquitt and Worth. Adult thrips from weed species using Berlese funnels and sticky traps in early and late season of peanut crop, leaf samples of weed species and peanut plants showing virus-like diseases phenotypes were collected. Total RNA was extracted from the collected samples and pooled into representative samples based on species and location and were sequenced on Illumina sequencing platform. Virome analyses was carried out with various bioinformatic tools, including kraken2, Trinity, NCBIBLAST+ and others to identify viruses. The results provide insights into the virus diversity in weed hosts, peanuts and the viruses acquired by thrips from weed hosts and transmitted to peanuts. This study reveals the orthotospovirus transmission networks from weeds to thrips to peanuts within peanut pathosystems.