ネギさび病菌夏胞子堆のSEM像

Uredosorus of Puccinia alli(De Candolle) Rudolphi on welsh onion leaf was investigated by scanning electron microscopy. In longituginal fructure of the rust tissues, the matured uredia were covered by only the host epidermis and contained paraphyses. Fungal hyphae were not recognized in the host epidermal cells. Uredospores were round and their surface were usually ornamented with spine-like structures. Spines were embedded in primaly wall of immature uredospore. The degeneration of this wall was iniciated near the apex of the spine appeared in cercular depression on the surface of spore.