Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Detection of an isolate of Andean potato latent tymovirus in ulluco (Ullucus tuberosus Caldas).

Abstract

Three major serological strain groups (Hu, CCC and Col-Caj) of potato Andean latent tymovirus (PALV) have been reported in potato. An isolate of PALV from asymptomatic ulluco (U. tuberosus) was mechanically transferred to Nicotiana clevelandii × N. bigelovii. The virus was identified by Ouchterlony double-diffusion tests using antiserum for PALV potato isolates, HU and CAJ-2. The ulluco isolate was purified and antisera were produced in rabbits. The average serological differentiation indexes of reciprocal tests were 2.5 for the ulluco isolate and CAJ-2 and 1.6 for the ulluco isolate and HU. DAS-ELISA was highly specific for PALV. Three hundred in vitro ulluco accessions maintained at CIP were tested by DAS-ELISA for the presence of the PALV isolate from ulluco using the antisera produced. PALV 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 PALV infecting ulluco, an Andean tuber crop frequently grown in close proximity to native potato cultivars. It gives support to the proposition that plant viruses can adapt to new hosts subsequent to long-term associations.