A novel luteovirus from sweet potato, sweet potato leaf speckling virus. uri icon

abstract

  • A virus obtained from accession DLP 1541 of the International Potato Center (CIP) sweet potato germplasm collection was shown to induce a curling and a white speckling of the leaves of infected plants. We propose to name it sweet potato leaf speckling virus (SPLSV). It was found in samples from 15 of 77 accessions tested and also in samples from farms at Chiclayo and Trujillo in northern Peru. SPLSV was transmissible by grafting, but not mechanically, and was transmitted in a persistent manner by Macrosiphum euphorbiae but not by Myzus persicae, Aphis gossypii or whiteflies. Isometric particles were purified from infected plants by procedures designed to purify luteoviruses. Reverse transcription and polymerase chain reaction amplification of RNA from SPLSV-infected plants using degenerate primers designed to amplify sequences either in luteovirus RNA or in potato leafroll virus (PLRV) RNA yielded c. 500 bp and c. 600 bp DNA fragments respectively. The nucleotide sequence of these fragments encoded two polypeptides characteristic in sequence of luteovirus proteins, which suggests that SPLSV should be classified in the genus Luteovirus. The amino acid sequence of the putative coat protein was 70% identical to that of PLRV. On the basis of the coat protein sequences, SPLSV is more similar to PLRV than is any other luteovirus. However, SPLSV particles did not react with antibodies to PLRV in ISEM or ELISA tests.

publication date

  • 1996
  • 1996