Preliminary Assessment of Resistance of Potato Varieties to Potato latent virus

Abstract

Sixty-one potato cultivars were assessed for their infectability with Potato latent virus (PotLV). Fifty eight were detected positive for PotLV by reverse transcription-polymerase chain reaction upon one or two mechanical inoculations. Virus was not detected in cultivars Caribe, Jemseg and Saco even after being mechanically inoculated three times. Secondary infection, which was assessed on the progeny plants by enzyme-linked immunosobent assay, was detected in all cultivars but Caribe, Jemseg and Saco. The three cultivars were then subjected to graft-inoculation with PotLV. Although detectable in the recipient rootstocks at 21 days post inoculation in all three cultivars, PotLV titer was lower in rootstocks than in scions. The same was true for tubers harvested from the graft-inoculated plants. Interestingly, progeny plants emerged from these tubers were PotLV-free. The results suggest that host resistance to PotLV exists in Caribe, Jemseg and Saco.