First Notice of Phytophthora Stem Base Rot on Syringa Vulgaris in a Polish Field Nursery

摘要

First Notice of Phytophthora Stem Base Rot on Syringa Vulgaris in a Polish Field NurseryPhytophthora citrophthora was isolated from grafted lilac (Syringa vulgaris). Showing browning of leaf blade edge and necrosis spreading on all leaves. On the stem bases, beginning from the grafted place, necrosis had even spread 20 cm upward, whereas root stock shoots and roots were healthy. Using rhododendron leaves as the bait, Phytophthora citrophthora was isolated from soil where growing plants showed stem base rot symptoms. Isolates of Phytophthora which were from the stem base, shoot tip of lilac, and soil, colonized leaves, stem parts and roots of lilac. Necroses spread about twice faster on leaf blades than on stem parts. Three isolates of Phytophthora colonized also Forsythia intermedia and Ligustrum vulgare.