Maize sterile stunt — a delphacid transmitted rhabdovirus disease affecting some maize genotypes in Australia

Abstract

A rhabdovirus disease causes severe stunting and sterility of a few susceptible maize (Zea mays L.) genotypes in eastern Australia. Maize sterile stunt virus (MSSV) also infected Aegilops variabilis Eig, barley (Hordeum vulgare L.), barnyard grass (Echinochloa colona (L.) Link.), triticale (x Triticosecale Wittmack), wheat (Triticum aestivum L.), T, aethiopicum Jakubz., T, monococcum L, and T. turgidum L. MSSV was transmitted with low efficiency by the maize planthopper Peregrinus maidis (Ashm.) and by Sogatella kolophon (Kirk.), but the chief natural vector was Sogatella longifurcifera Esaki and Ishihara, a delphacid found commonly on affected maize and on E. colona. The incubation period of MSSV in P, maidis was 10-14 days after acquisition on infected plants or 9-12 days after injection of infective sap. Transmission was demonstrated during a period of up to 23 days or until the insects died. Field incidence in the maize lines B37 and H84 often exceeded 90 %, but most maize lines were resistant and resistance was highly dominant. Temperate cereals were severely affected only during summer and triticale was the most susceptible. Particle dimensions were 230 by 50 nm in negative stain and 255 by 45 nm in thin section, with accumulations of particles found only in cytoplasmic vesicles. MSSV particles occurred mainly in companion cells, phloem parenchyma and bundle sheath cells in maize. Virus-like particles were also found in the brain and salivary glands of infective P. maidis.