Field and culture studies of Streblonema macrocystis sp. nov. (Ectocapales, Phaeophyceae) from Chile, a sexual endophyte of giant kelp

Abstract

Streblonema macrocystis sp. nov. (Phaeophyceae) is described from plants endophytic in Macrocystis pyrifera (Linnaeus) C. Agardh at Valdivia, Chile. The life history, which was studied in the field and in laboratory culture, shows alternation of two slightly heteromorphic microscopic generations growing in different parts of the same host. The sporophyte is found in the sporophylls of Macrocystis and the dioecious gametophytes in the basal part of the stipe and the rhizoids that persist during winter. This is the first time that sexuality has been observed in a species of Streblonema.