The influence of fixation procedure on the ultrastructure of the host–endophyte interface of vesicular-arbuscular mycorrhizae

The ultrastructure of the interfacial zone which separates the intracellular structures of vesicular-arbuscular mycorrhizal fungi from host cytoplasm has been described in a variety of ways by recent investigators. Evidence is presented here which suggests that previous interpretations of the ultrastructure of the interfacial zone have been based on an artifact of fixation. Using an improved procedure, a dense, granular material was found in the interfacial zone. This material was preserved by simultaneous glutaraldehyde-osmium fixation but not by conventional prefixation and postfixation in glutaraldehyde and osmium, respectively.

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A new method for observing the morphology of vesicular–arbuscular mycorrhizae

Canadian Journal of Botany ◽

10.1139/b84-290 ◽

1984 ◽

Vol 62 (10) ◽

pp. 2128-2134 ◽

Cited By ~ 310

Author(s):

M. C. Brundrett ◽

Y. Piché ◽

R. L. Peterson

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizae ◽

Arbuscular Mycorrhizal ◽

Staining Procedure ◽

Acid Fuchsin ◽

Vesicular Arbuscular Mycorrhizal Fungi ◽

Vesicular Arbuscular ◽

Contrast Microscopy ◽

Interference Contrast Microscopy

A new procedure using chlorazol black E has been developed for staining vesicular–arbuscular mycorrhizal fungi in cleared roots. In a comparative study, chlorazol black E was found to be much superior to previously used stains (acid fuchsin, trypan blue, aniline blue) for showing details of internal hyphae and particularly arbuscules. This clearing and staining procedure, combined with Nomarski interference contrast microscopy, revealed details of arbuscule structure not evident with previous techniques. Field-collected samples were also stained well by this procedure. The procedure should allow more accurate assessment of roots for colonization by vesicular–arbuscular mycorrhizal fungi.

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Colonization of crop and pasture species with vesicular–arbuscular mycorrhizal fungi and a negative correlation with root infection by Bipolaris sorokiniana

Canadian Journal of Botany ◽

10.1139/b89-092 ◽

1989 ◽

Vol 67 (3) ◽

pp. 687-693 ◽

Cited By ~ 32

Author(s):

J. P. Thompson ◽

G. B. Wildermuth

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizae ◽

Arbuscular Mycorrhizal ◽

Bipolaris Sorokiniana ◽

Mycorrhizal Colonization ◽

Root Infection ◽

Vesicular Arbuscular Mycorrhizal Fungi ◽

Vesicular Arbuscular ◽

Mycorrhizal Roots

The roots of 37 crop and pasture species were assessed for vesicular–arbuscular mycorrhizae in a vertisol containing spores of vesicular–arbuscular mycorrhizal fungi mainly Glomus mosseae, and of the pathogenic fungus, Bipolaris sorokiniana. The level of mycorrhizal colonization of different hosts is an important aspect of managing crop sequences to reduce "long fallow disorder." All species except rapeseed in the Cruciferae and lupin in the Leguminosae were hosts, although perennial rye grass in the Gramineae had only very slight colonization. The percent root length colonized as assessed by the grid-intersect method ranged up to 60.5% for wheat in the winter series and up to 98.4% for mungbean in the summer series. Greatest weights of mycorrhizal roots were produced by phalaris grass, chickpea, safflower, cocksfoot, lucerne, and barley in the winter series and by lucerne, maize, canary seed, Sudan grass, grain sorghum, and buffel grass in the summer series. Although Gramineae as a group tends to have fine roots with a low percentage of mycorrhizal colonization, the total weight of mycorrhizal roots can be large, and they should be at least equal to legumes in effectiveness for breaking long fallow disorder. Percentages of mycorrhizal colonization determined by the grid-intersect and three slide methods were generally well correlated with one another, but all were less strongly correlated with weight of mycorrhizal roots for winter crops and were entirely uncorrelated with weight of mycorrhizal roots for summer crops. Significant inverse-regression relationships were obtained between infection of root segments (but not of stem bases) by B. sorokiniana and root colonization with vesicular–arbuscular mycorrhizae, indicating that vesicular–arbuscular mycorrhizal fungi antagonise root infection by B. sorokiniana.

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