XVI International Botanical Congess

Trebouxiophyceae incluides coccoid, sarcinoid, palmelloid green freshwather algae with counter clockwise absolute orientation of flagellar apparatus. Five strains identefied as Myrmecia and Parietochloris spp. were isolated from soils of Russia. The investigations of ultrastructure of zoospores and vegetative cells revealed significant variations in organization of flagellar apparatus, specialy in pattern of fibrillar roots. Three types of connections between basal bodies and nuclei were described: direct connections, rhizoplasts, membrane-fibrillar structures. The presens of pyrenoid in vegetative cells of some Myrmecia strains indicates the necessity of revision of the genus. Ultrastructural peculiarities of flagellar root organization could be useful for taxonomy of low level in cl.Trebouxiophyceae