Characteristics of a Latent Potyvirus Seedborne in Guar and of Guar Green-Sterile Virus

Abstract

A symptomless, seedborne potyvirus was isolated from guar (Cyamopsis tetragonoloba) germ plasm in Griffin, Georgia. The host range and serology were similar to those reported for guar green-sterile virus (GGSV) and guar symptomless virus. Biological, serological, and molecular comparisons of the Georgia isolate and the South African GGSV indicate they are similar and are closely related to bean common mosaic potyvirus (BCMV). The Georgia isolate is seed-transmitted at a rate of up to 94% in guar line PI 340385. Sequence analysis of the capsid protein (CP) gene and the 3′-untranslated region (3′-UTR) showed that both isolates are 96% homologous. GenBank searches indicate that both are related to various strains of BCMV. The highest CP nucleotide sequence and 3′-UTR identities of 91 and 93%, respectively, were with those of BCMV-NL4. On this basis, both isolates from guar should be considered as strains of BCMV.