A PRELIMINARY STUDY ON THE PATHOGENICITY OF PICEA KORAIENSIS L. LEAF RUST

Leaf rust of Picea koraiensis L. is caused by Chrysomyxa rhodod-endri de Bary. Its pycnia, aecia occur on the first-year new leaves. They reduce forest increment by causing premature defoliation. Its uredinia occur on the leaves of Rhododendron dahuricum. They are orange-coloured and exc-urrent. But a few uredinia occur on the shoots. Telia are brownish-red colour and oval in shape. It will produce basidiospores in the following summer and reinfect the shoots of Picea koraiensis.