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ELECTRON MICROSCOPY OF PHIALOCONIDIOGENESIS IN METARRHIZIUM ANISOPLIAE
Author(s) -
Hammill Terrence M.
Publication year - 1972
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1972.tb10099.x
Subject(s) - conidium , biology , electron microscope , ultrastructure , anatomy , organelle , cell wall , biophysics , botany , microbiology and biotechnology , optics , physics
Fine‐structure observations with two different fixation procedures showed that phialide necks possessed a thickened electron‐transparent wall layer. Phialoconidia developed from a wall layer which originated 1–1.5 μm within phialide necks. After conidium initials blew out of phialide tips and organelles entered, conidia were delimited by transverse septa which did not appear to be plugged by Woronin body‐like plugs. Instead, septa appeared to become functionally complete by continued centripetal growth. Conidium‐delimiting septa moved distally out of phialide necks as subsequent conidium initials formed. During this distal movement, septa increased in thickness and lamellae appeared on the conidium side; mature conidia had bipolarly lamellate cell walls. Conidial walls had a thin, ridged electron‐dense outer wall layer and a thicker electron‐transparent inner wall layer which increased in thickness centripetally after septum delimitation. Conidia were usually uninucleate and possessed conspicuous storage vacuoles with lipid and protein contents. Conidia also possessed numerous presumably lipid droplets. Multivesicular bodies were observed near conidium‐delimiting septa and conidium walls which were increasing in thickness.