Aetiology of the leaf roll disease of potatoes in New Zealand

Abstract

The aetiology of the leaf roll disease of potatoes was investigated using the enzyme-linked immunosorbent assay (ELISA) and by aphid transmission to indicators. Potato leaf roll virus (PLRV) was the only causal agent identified; beet western yellows virus (BWYV) was not isolated from PLR-diseased plants. Both polyclonal and monoclonal antisera, to BWYV and PLRV, were evaluated for their specificity in ELISA. Weak, heterologous reactions between BWYV antisera and PLR-diseased potato plants frequently occurred. The same plants reacted strongly with PLRV antisera. Indicator plants for PLRV and BWYV were tested to see if they could be used as differential hosts, i.e., susceptible to one virus, but not the other. Crambe abyssinica and shepherd's purse (Capsella bursapastoris) were differential hosts for BWYV, whereas tomato, Datura stramonium, and Datura tatula were differential hosts for PLRV. Physalis floridana was susceptible to both BWYV and PLRV.

Keywords:

• potato leaf roll virus
• beet western yellows virus
• aetiology
• differential indicators
• potatoes
• ELISA