Disease Note.

Detection of an Isolate of Andean Potato Latent Virus in Ulluco (Ullucus tuberosus Caldas). C. Lizirraga, International Potato Center (CIP), Apartado 1558, Lima 100, Peru. M. Santa Cruz, and U. Jayas-inghe, International Potato Center (CIP), Apartado 1558, Lima 100, Peru. Plant Dis. 80:344. Accepted for publication 24 January 1996. Copyright 1996 The American Phytopathological Society. DOI: 10.1094/PD-80-0344A.

Three mayor serological strain groups (Hu, CCC, and Col-Caj) of Andean potato latent tymovirus (APLV) have been reported in potato (1). An isolate of APLV from asymptomatic ulluco (Ullucus tuberosus Caldas) was mechanically transferred to Nicotiana clevelandii Gray x N. bigelovii (Torr) S. Wats. The virus was identified by Ouchterlony double-diffusion tests using antiserum for APLV potato isolates, HU (from C. Fribourg) and CAJ-2. The ulluco isolate was purified and antisera were produced in rabbits. The average serological differentiation indexes of reciprocal tests (RSDIs) were 2.5 for the ulluco isolate and CAJ-2, and 1.6 for the ulluco isolate and HU. The double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) is highly specific for APLV detection (1) and APLV was not detected previously by DAS-ELISA in ulluco using antiserum for the APLV isolates from potato, HU or CAJ-2. Three hundred in vitro ulluco accessions maintained at CIP were tested by DAS-ELISA for the presence of the APLV isolate from ulluco using the antisera produced. APLV was detected in 64/189, 10/64, 4/4 and 4/21 accessions from Peru, Bolivia, Colombia and Argentina, respectively. This is the first report of APLV infecting ulluco, an Andean tuber crop frequently grown in close proximity to native potato (Solanum tuberosum L. subsp, andigena (Juz. & Buk.) Hawkes and other species) cultivars. It gives support to the proposition that plant viruses can adapt to new hosts subsequent to long-term associations.