Transmission and Host Plant Resistance of Cotton leafroll dwarf virus (CLRDV) in the Southeastern United States

Abstract

Cotton leafroll dwarf virus (CLRDV) is an aphid transmitted Polerovirus responsible for severe yield losses in Brazil and is the first virus reported to infect cotton in the Southeastern United States. As a new strain, transmission and host plant resistance to CLRDV-AL are unknown and require investigation. Seed, mechanical, and grafting transmission were evaluated, an aphid-based screening assay protocol developed, and transmission by the aphid vector, Aphis gossypii, was characterized in this study. CLRDV-AL was not transmitted by seed or mechanical inoculation but was transmissible by grafting and A. gossypii. Aphids were shown to acquire the virus in 30 minutes, retain it for 23 days, and could inoculate in 15 minutes. The leaf disc assay proved that all lines tested could be inoculated with CLRDV-AL. Next, these screening protocols need to be utilized on a diverse range of germplasm to screen for resistance.