Potato virus X : detection and inter-relationship with Verticillium dahliae and Colletotrichum atramentarium

Graduation date: 1980Preliminary studies were run to determine the sensitivity and\ud reliability of enzyme-linked immunosorbent assay (ELISA) for the\ud detection of potato virus X (PVX). ELISA was found to be capable of\ud detecting PVX in tobacco at a 1:3333 sample dilution. The reliability\ud of ELISA for the detection of PVX in potato was found to be\ud comparable with that obtained by Gomphrena globosa bioassay and far\ud superior to that obtained by greenhouse symptomatology of potato\ud plants.\ud ELISA was used in a large-scale survey of PVX to determine what\ud role, if any, PVX had on the early death of potato vines, a yieldlimiting\ud symptom-complex associated with the presence of Verticillium\ud dahliae. Presence of PVX is correlated with increased severity of\ud V. dahliae infection in variety 'Russet Burbank'. The probability of\ud random occurrence (a) of this correlation was .001. The effect of\ud PVX on V. dahliae colonization was most pronounced in fields where\ud early dying was most severe and the effect of PVX, on V. dahliae\ud colonization appeared to be seed-source dependent. Results suggest\ud that the use of virus-free seed may be a useful cultural practice\ud for reducing the level of early dying of potato vines. An inverse\ud relationship was observed between PVX infection and the incidence\ud and severity of Colletotrichum atramentarium infection, (a = .001),\ud possibly due to an effect of the virus on plant nutritional levels