Comparison and characterization of maize stripe and maize line viruses

Abstract

SUMMARYTwo morphologically similar viruses isolated from maize in East Africa induced two distinct symptom types in maize. One, designated maize stripe virus (MSV), showed broad yellow stripes or a yellowing of the entire leaf, acute bending of the shoot apex and severe stunting. The second, maize line virus (MLV), induced continuous, narrow yellow lines along the leaf veins and did not cause apical bending or stunting. MSV and MLV were both transmitted by Peregrinus maidis (Delphacidae), but not by Cicadulina mbila (Jassidae) or by sap inoculation.Both viruses were purified by extracting systemically infected leaves in 0–5 M sodium citrate buffer and clarifying with 7 ml n‐butanol/100 ml extract, followed by differential, and finally sucrose density gradient, centrifugation.Partially purified preparations of both viruses contained isometric viruslike particles of two sizes: MSV particles were 35 and 40 nm in diameter with sedimentation coefficients (so2o, w) I09 anI0o respectively; MLV particles were 28 and 34 nm in diameter. Antisera prepared against MSV and MLV had dilution end points of 1/128 and 1/64 respectively in agar‐gel diffusion tests.In tests with low‐titre antisera, MSV did not react with MLV antiserum and MLV did not react with MSV antisreum; in the presence of antiserum containing antibodies to both MSV and MLV, the two viruses formed precipitin bands which crossed in the pattern of non‐identity. Maize streak virus and maize mottle virus showed no serological relationship with MSV or MLV.On the basis of particle size and serology MSV and MLV are shown to be two distinct and possibly unrelated viruses.MSV and MLV apparently are dissimilar from any characterized viruses of the Gramineae.