Fine structural features of rhizomorphs (sensu latu) produced by four species of lichen fungi
1997
Sanders, William B. | Ascaso, Carmen
9 pages, figures, and tables statistics.
Afficher plus [+] Moins [-]Linear mycelial aggregates (rhizomorphs) produced by the squamulose lichens Toninia opuntioides Squamarina cartilaginea, Lecanora rhizinata, and Acarospora scotica were examined by transmission electron microscopy (TEM). Cytological features typical of lichenized mycobionts were present, including concentring bodies and plasmalemma invaginations. Some septa in rhizomorphs of S. cartilaginea and A. scotica appeared to be multipored. Septal pores were usually plugged by an electron-dense structure.Intrahyphal hyphae were common to abundant in the rhizomorphs of all four species examined. The wall of the invasive hypha was continous with inner wall layers of the cell of origin. Contacts between adjacent hyphae involved wall dissolution and formation of new wall layers, leading to anastomosis and/or possibly to intrahypal invasion. Differentiation of an outer layer of collapsed cells in rhizomorphs of Sqamarina cartilaginea and of extremely thick-walled cells Lecanora rhizinata was evident, but no anatomical specialization comparable to the "vessel hyphae" of non-lichen linear mycelial organs was observed. Enlarged spheroid or ovoid cells with dense cytoplasm, numerous mitochondria and lipid reserves ocurred in short chains in rhizomorphs of Acarospora scotica; infrequently, similar cells were observed singly in those of Squamarina cartilaginea. These cells were reminiscent in shape of certain types of oil hyphae found in endolithic lichens, although often the lipid content of the enlarged cells was not particularly pronounced.
Afficher plus [+] Moins [-]Peer reviewed
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