The relationship between sugar-cane mosaic virus and mosaic viruses of maize and Johnson grass in Australia

Abstract

Two isolates of maize dwarf mosaic virus originating from maize (MDMV(M)) and Johnson grass (MDMV(J)) were distantly related to an Australian and a Californian strain of sugar-cane mosaic virus (SMV). MDMV(M) was shown to be distantly related serologically to a Californian strain but not to an Ohio strain of MDMV; MDMV(J) was not shown to be related serologically to either the Californian or the Ohio strain of MDMV.

MDMV(M), MDMV(J), and the Australian SMV produced similar symptoms on sweet corn (Zea mays var. saccharata (Sturtev)), which under glasshouse conditions included an initial necrotic phase not previously described for MDMV.

The three isolates showed different characteristics when purified from sweet corn by an identical procedure. The yields of MDMV(M) and MDMV(J) were higher than that of SMV, and these two isolates produced strong zones in density gradients whereas SMV produced a very weak zone.

The normal length of MDMV(M) was 773 ± 6.35 mµ and that of MDMV(J) 778 ± 6.35 mµ and the particles of both were uniform. By contrast the particles of SMV were very uneven in length; the most common length was 650–750 mµ, but many longer and shorter particles were observed.