@conference {50967,
	title = {A method for analyzing active internal colonization of dark septate fungal endophytes in grasses and shrubs native to arid southwestern USA rangelands},
	booktitle = {Third International Conference on Mycorrhizae},
	year = {2001},
	month = {July 8-13, 2001},
	pages = {Abstract No. P1-68},
	address = {Adelaide, Australia},
	abstract = {Dominant native grasses and shrubs in arid southwestern USA rangelands are more extensively colonized by dark septate fungal endophytes (DSE) than by conventional mycorrhizal fungi.  These endophytes are widespread colonizers in most ecosystems, but their ecological function is currently unresolved. They are readily observed as stained or melanized septate hyphae and  microsclerotia on the root surface and in the cortex using fungus specific stains that bind to chitin, a common wall component.  Roots of grasses and shrubs native to the northern Chihuahuan Desert were stained with sudan IV, specific for lipids, and analyzed with high magnification differential interference microscopy.  Inconspicuous internal hyphal extensions of stained or pigmented hyphae were observed that were not visible using fungus specific stains.  These structures were observed in a much greater frequency than the commonly recognized stained or pigmented structures in  physiologically active roots.  Differential responses to staining were attributed to structural differences and levels of chitin incorporation in the fungal wall.  Internal hyphae varied in diameter, wall thickness, and visibility and in many cases were detectable only because of the positive staining of lipids in fungal vacuoles.  Internal hyphae grew both inter and intracellularly within the cortex and sieve elements of the vascular cylinder and at time contained substantial quantities of lipids.  This method promises to be effective for studying the extent, nature, and possible function of DSE fungi in native ecosystems.},
	keywords = {analyzing, arid rangelands, dark septate, fungal endophytes, grasses, internal colonization, shrubs},
	author = {J.R. Barrow and Aaltonen, R.E.}
}
