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APR 15 1987 !
Ectomycorrhizal Fungi of Florida I
auction to Mycorrhizal Fungi and
preliminary Studies in Florida
Richard E. Baird
1 T / **-I 1*f
I ter of Florida james w. KimDrougnh
F-lor i daCoperati ve xteierice / Institute of Food and Agricultural Sciences / University of Florida / John T. Woeste, Dean
Many microorganisms are present in the soil
around the roots of trees and plants. Some are
pathogenic, many are involved in wood and litter
decay, while others are directly involved in
symbiotic relationships. Almost all plants, spe-:
cifically forest tree species, require a beneficial
or symbiotic relationship with certain genera and
species of fungi. This relationship is termed a
mycorrhizal association. The term "Mycorrhiza" was
first used to mean "fungus root". The fungus acts
as a secondary root system for the plant by pro-
viding the nutrients (calcium, nitrogen, phosphorus,
potassium) and water uptake which normally would
not be available to the trees (Fig. 1). These fungi
can break down complex minerals and organic mat-
ter to be passed to the trees. Mycorrhizal fungi
can also act as a physical barrier or they release
chemicals which may prevent or inhibit infections to
the plant by pathogenic organisms. The host, in
turn, supplies, photosynthetic products such as
carbohydrates (sugars), amino acids and other min-
erals to the fungus for growth.
The use of chemical fertilizers has been shown
to increase tree seedling survival and growth.
These compounds are not used, however, because of
the large expense which makes use of such
fertilizers impractical. Use of mycorrhizal fungi,
therefore, can be significantly important in
increasing survival and growth of seedlings planted
for reclamation or reforestation work on disturbed
sites such as coal mine spoils, severely burned areas
or phosphate mines which are deficent in nutrients.
It has been shown repeatedly that in coniferous
forests ectomycorrhizae are absolutely essential for
the establishment and normal growth of seedlings.
There are generally considered to be two types
of mycorrhizal fungi, including ectomycorrhizae
and endomycorrhizae. The endomycorrhizal fungi
grow in the cortical cells of the root and do not
form a thick layer of tissue around the root hairs.
In this fact sheet we are primarily concerned with
ectomycorrhizae. These fungi invade the feeder
roots of woody plants forming a fungal mantle or
thick layer of tissue around the surface of the root
(Fig. 2). For the true ectomycorrhizal association
to occur, the fungus initially forms a mantle of
hyphae around the surface before it penetrates the
root between the outer cortical cells to form what
is called the Hartig Net. The Hartig net is the
main distinguishing feature which defines ecto-
mycorrhizae, since a number of fungi might form
what could be interpreted as a mantle. The roots
S*Richard E. Baird is a former Visiting Research Assistant and James W. Kimbrough is Professor of Mycology, Botany Depart-
ment, IFAS, University of Florida, Gainesville.
Figure 3. Figure 4.
Figure 8. Figure 9.
Figure 15. Figure 16.
Fig. 3. Laccaria bicolor (Basidiomycete) Fig. 10. Saphaerosporella brunna (Aco>om cete)
Fig. 4. Ticharina sp. (Ascomycete) Fig. 11. Lactmrius chelidonium (Basiodiom.cete)
Fig. 5. Boletus decipens (Basidiomycete) Fig. 12. Sepularia sumneriani (AscomN cete)
Fig. 6. Alycolachnea hemipharerica (Ascomycete) Fig. 13. Elaphomyces granulalus (Zygomycele)
Fig. 7. Pisolithus linctorius (Basidiomycete) Fig. 14. Amanita rubescens (Ascom icete)
Fig. 8. Suillis pinorigidus (Basidiomycete) Fig. 15. Geastrum saccatum (Basidiomnycele)
Fig. 9. Lycoperdon gemmata (Basidiomycete) Fig. 16. Hy'sterangium sp. (Zygom\cete)
usually become forked to multiforked or are in
other irregular shapes. The color of the mantle
varies depending upon the fungal species. They may
be brown, black, red, yellow or a variety of other
colors. These fungi belong to the higher Basidio-
mycetes (mushrooms and puffballs), for instance
members in the families of the Boletaceae, Hygro-
phoraceae, Gomphidiaceae, Russulaceae, Strobilo-
mycetaceae, Cantharellaceae, and Hydnaceae. Other
fungi forming ectomycorrhizae are Ascomycetes
(cup fungi and truffles) and Phycomycetes, but
these perhaps to a lesser degree.
The ectomycorrhizal fungi form the asso-
ciations mainly with woody plants and major forest
tree species such as members in the Pinaceae
(pines, true firs, hemlock, spruce and others),
Fagaceae (oaks, beech and others), Betulaceae
(birch, alders and others), Salicaceae (poplars,
willows and others), and Tiliaceae (basswood). On
a given tree root, many ectomycorrhizal fungal
species can be found. A tree species, therefore,
can be a host to a number of fungi. Douglas fir in
the northwestern United States has been shown to
have more than 200 ectomycorrhizal partners. In
turn, a single fungus can have a broad host range
or can be found on many trees from several genera
Previous studies have shown that certain
ectomycorrhizal fungi are very important for use in
reclamation and reforestation work. In one study by
Don Marx from the U.S. Forest Service, conducted
in Florida, the ectomycorrhizal fungus Pisolithus
tinctorius was shown to significantly increase the
survival and growth of slash pine and sand pine.
Current Ectomycorrhizal Studies In Florida
At the University of Florida, a study was
undertaken to examine the major ectomycorrhizal
fungi occurring in Florida and determine which of
them will be most useful in reclamation and
reforestation work. Mushrooms and puffballs are
being collected and isolated in culture (tissue placed
on a growth solution). The active growing fungi
obtained from the mushrooms and puffballs are then
tested to see if they will form the ectomycorrhizal
association with the three most economically
important tree species of Florida including foblolly
pine, sand pine, and slash pine. The fungi are
placed or inoculated in the soil adjacent tq4hsi%,
seedlings roots growing aseptically in containers~,
test tubes with a peatmoss/vermiculite mixture (1:9)
and growth solution.
In current tests, cultures of numerous species
belonging to several genera are being used to
attempt mycorrhizal synthesis (Table 1). Suillis
pinorigidus and Boletinus decipens, which belong to
the pored mushrooms, were found to commonly
form the ectomycorrhizae with the three important
tree species in Florida Also, the puffball forming
Scleroderma aurantiacum was found to be a good
mycorrhizal former in the preliminary tests with
loblolly pine, slash pine and sand pine. From these
results, the fungal tissue of those species are being
grown in the laboratory to be used for future test
plantings in former coal mines spoils and phosphate
mines which are to be reclaimed.
Cultures of the fungi listed in Table 1 are
available through the Botany Department, University
of Florida, Gainesville, 32611. Color photographs of
representatives of the Basidiomycetes, Ascomycetes,
and Zycomycetes are found in the color plate
containing Figures 3 through 16.
Table 1. List of Ectomycorrhizal Fungi Currentlyz Being Tested.
Lactarius chelidonium var. chelidonium
z = Isolation of other fungi from the field being conducted.
This publication was promulgated at a cost of $1,573.75, or 52 cents per copy, to provide information on the potential of
ectomycorrhizal fungi in improving the growth of economically important forest trees to Florida foresters, county Extension
agents and other interested individuals. 2-3M-87
COOPERATIVE EXTENSION SERVICE, UNIVERSITY OF FLORIDA, INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES, K.R. Tefertiller,
director, in cooperation with the United States Department of Agriculture, publishes this information to further the purpose of the May 8 and
June 30, 1914 Acts of Congress; and is authorized to provide research, educational information and other services only to individuals and institu-
tions that function without regard to race, color, sex or national origin. Single copies of Extension publications (excluding 4-H and Youth publica-
tions) are available free to Florida residents from County Extension Offices. Information on bulk rates or copies for out-of-state purchasers is """
available from C.M. Hinton, Publications Distribution Center, IFAS Building 664, University of Florida, Gainesville, Florida 32611. Before publicizing this publication, *
editors should contact this address to determine availability. ,--/