DETECTION AND OCCURRENCE OF PRIMARY INFECTION BY POTATO VIRUS S OF DISEASE-FREE PLANTS

Abstract

Using enzyme-linked immunosorbent assay (ELISA) and potato plantlets of cultivars Green Mountain, Red Pontiac, Russet Burbank and Shepody, potato virus S (PVS) was detected in primary infected plants under field conditions. Potato virus S was detected 3 wk postinoculation (p.i.) from the field-grown plants as compared to 2 wk p.i. from greenhouse-grown plants. Potato virus S concentration in infected plants remained high throughout the growing season. The ELISA test using dormant tubers was not reliable because A405 nm values overlapped between infected and healthy tubers. Exposure of healthy plants to PVS sources in the field resulted in high infections with PVS by the 9th wk of growth. This pattern of infection suggests involvement of aerial vectors in the transmission of PVS under conditions of the Atlantic region of Canada.Key words: Current year infection, ELISA, dormant tubers, spread of PVS