CHARACTERISTICS OF A LATENT POTYVIRUS SEED-BORNE IN GUAR AND OF GUAR GREEN-STERILE VIRUS

A symptomless, seedborne potyvirus was isolated from guar (Cyamopsis t etragonoloba) germ plasm in Griffin, Georgia. The host range and serol ogy were similar to those reported for guar green-sterile virus (GGSV) and guar symptomless virus. Biological, serological, and molecular co mparisons of the Georgia isolate and the South African GGSV indicate t hey are similar and are closely related to bean common mosaic potyviru s (BCMV). The Georgia isolate is seed-transmitted at a rate of up to 9 4% in guar line PI 340385. Sequence analysis of the capsid protein (CP ) gene and the 3'-untranslated region (3'-UTR) showed that both isolat es 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-N L4. On this basis, both isolates from guar should be considered as str ains of BCMV.