Sources of resistance in opium poppy against downy mildew disease incited by Peronospora arborescens (Berk de Bary)

摘要

Opium poppy (Papaver somniferum L.) is the most important medicinal crop of India. Downy mildew caused by Peronospora arborescens (Berk de Bary) is a most common and destructive disease of opium poppy. In the past, no critical attempts were made to find varieties of opium poppy resistant to this disease, except for Prochaska (1928). Systemic infection occurs through oospores penetrating the roots; non-systemic through conidia infecting the leaves. No work has been done on the ability of the roots toresist the soilborne infection and the leaves to resist airborne infections.