Laminariocolax aecidioides (Phaeophyceae) epi-endophytic in Undaria pinnatifida (Phaeophyceae) in patagonian coasts of Argentina

GAUNA, M.C.; PIZANI, N.V.; PARODI, E.R.

Viena, Austria

Congreso; XVII International Botanical Congress; 2005

International Botanical Society

Laminariocolax aecidioides has been considered like an epi-endophytic organism of the kelps of the North Pacific, Artic and European coasts, extending its distribution to the South hemisphere. The  thalli of U. pinnatifida infected by this species were collected in the intertidal zone of the patagonian coasts of Argentina. On cuticle of the kelp the infection developed as dark spots of 1 - 2 mm that covered partially fronds and sporophyles. In the cortical and medullar zones of U. pinnatifida, the infectants cells occupied the intercellular spaces without penetrating in the host cells. The thallus of L. aecidioides formed a postrate layer of filaments on the surface of the host. The reproductive structures were formed in the erect system. The uniloculars sporangia were uniseriate, ovoid and exhibited basal or apical dehiscence, and the pluriloculars were extended. The invasion was neither associate to ruptures or perforations in the thalli of kelp, although it was well-known a predominance of the thalli of L. aecidioides related to the openings of the glands of mucilage and depressions of the epidermic layer of the host.