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SCANNING ELECTRON MICROSCOPY OF CRYOFIXED MYCORRHIZAS OF SITKA SPRUCE, PICE A SITCHENSIS (BONG.) CARR.: A COMPARISON WITH CRITICAL POINT‐DRIED MATERIAL
Author(s) -
ALEXANDER CLARE,
JONES D.,
McHARDY W. J.
Publication year - 1987
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1987.tb00899.x
Subject(s) - cryofixation , critical point (mathematics) , scanning electron microscope , botany , mycorrhiza , hypha , materials science , mineralogy , chemistry , ultrastructure , biology , composite material , mathematical analysis , mathematics , genetics , symbiosis , bacteria
S ummary Critical point‐drying is the standard method of preparation for scanning electron microscope studies of mycorrhizas. However, a number of recent studies on various biological specimens have shown disadvantages associated with this technique. These can be overcome by cryofixation, where specimens are frozen in liquid nitrogen and viewed in the frozen‐hydrated state. Three distinct types of mycorrhiza of Sitka spruce [Picea sitchensis (Bong.) Carr.] were critical point‐dried or cryofixed, and were examined for differences in the preservation of both surface features and internal morphology after fracturing or cutting the material transversely. Surface features were better preserved in frozen‐hydrated mycorrhizas than in critical point‐dried ones. Surface cementing matrix seen in the former was partially or entirely removed by critical point‐drying. Some distortion of both fungal and plant cells also occurred after the latter treatment, and cell contents retained in frozen‐hydrated specimens were often lost after critical point‐drying. Fractured frozen‐hydrated material revealed surface features of the cortical cells and lobed Hartig net hyphae.