Lucerne transient streak and lucerne latent, two new viruses of lucerne

Abstract

A previously undescribed virus, lucerne transient streak virus (LTSV), and two isolates of lucerne latent virus (LLV) were sap-transmitted from symptomless lucerne to Chenopodiurn quinoa and to herbaceous species of several families. Only LTSV could be mechanically transmitted to lucerne. LTSV was purified by clarifying C. quinoa leaf extracts with n-butanol, followed by differential and sucrose density gradient centrifugation. Isometric particles 27 ± 1 nm in diameter sedimented as a single component with a S20,w value of 114 S. An antiserum prepared against LTSV did not react with either isolate of LLV. LTSV was not seed-transmitted. LTSV reduced the dry matter yield of lucerne during one growing season by 18 % in the field and by 12% in a glasshouse. Various attempts to purify the two isolates of LLV were unsuccessful, but a few isometric particles 24–28 nm in diameter were observed in some preparations. One isolate of LLV was transmitted in 8% of lucerne seed and 9% of C. quinoa seed from infected plants. The viruses did not react against antisera to 23 other viruses and were not soil- or aphid-borne.