Seed transmission of the High Plains virus in sweet corn

The High Plains vints (HPV), which infects corn and other cereals, was firs t found in 1993 in the United States. Research was initiated in 1995 to inv estigate the potential for seed transmission of HPV. Sweet corn seeds of va rious cultivars harvested in 1994 to 1996 from 13 fields and research plots in southwestern Idaho, Colorado, and Nebraska were seeded in potting mix i n the greenhouse. Leaf samples collected at the three- to six-leaf stage fr om both symptomatic and asymptomatic plants were tested by enzyme-linked im munosorbent assay (ELISA). Of the 46,600 seeds planted, 38,473 seedlings em erged, and three tested positive by ELISA, exhibited mosaic symptoms, and h ad the presence of HPV confirmed by an additional test. One of the positive plants was used for successful acquisition and transmission of HPV by the wheat curl mite to Westford barley. The other two plants were used to succe ssfully transfer HPV to other corn plants by vascular puncture inoculation of seed. These results indicate that HPV can be seed transmitted at a very low frequency in sweet corn.