First report of Plasmopara obducens in Australia
In Australia, impatiens plants (Impatiens walleriana cv. ‘Fiesta’) showing symptoms of downy mildew and growing in a commercial nursery near Melbourne (Victoria) were sent for diagnosis in October 2006. Laboratory analysis (morphology and DNA sequencing) confirmed the presence of Plasmopara obducens (EPPO Alert List). Investigations done at the same nursery showed that other cultivars (with single and double flowers) were affected. Most diseased plants were grown from seed, but some from cuttings. The disease was not observed on vegetatively propagated New Guinea hybrids (Impatiens x hawkeri). Additional surveys revealed the presence of P. obducens in other Australian states: New South Wales, Queensland, and South Australia. This is the first report of P. obducens in Australia.
Sources
New Disease Reports. BSPP website (last retrieved 2007-04).
Cunnington JH, Aldaoud R, Loh M, Washington WS, Irvine G (2006) First record of Plasmopara obducens (downy mildew) on impatiens in Australia. http://www.bspp.org.uk/ndr/jan2007/2006-96.asp