1. The Role of Relatedness in Competitive Outcomes of
Unit-Restricted Fungi on Discontinuous Substrates
Montgomery College
e n d l e s s p o s s i b i l i t i e s
Md R Hossain
SC297
AbstractAbstract
Fungal interactions determine the success of survival in competitive
situations. These limits include the efficiency of consuming resources
on a given patch and the efficiency allocating gained resources towards
reproduction. Unit-restricted fungi are those that are not able to migrate
between patches of usable resources through vegetative mycelium;
rather, they must colonize new patches through the dispersal of their
spores. I sought out to test the theory that competitive interactions
between "sibling" unit-restricted fungi would be passive compared to
those between fungi of a large genetic difference. I present the control
data for the species Coprinus congregatus and Coprinus cinereus by
growing them in JP1X agar and measured growth daily. The data
showed linear growth patterns in both linear growth and area growth
data. The rate of growth, however, is very scattered. The lines of best fit
show a decrease in linear growth rate in both species, except for Bolt,
who showed no change. The lines of best fit for area growth showed an
expected increase. However the rate of area growth is scattered, and
data remains ambiguous in its effectiveness to test the hypothesis.
IntroductionIntroduction
Fungal interactions determine the success of survival in competitive
situations. These limits include the efficiency of consuming resources
on a given patch and the efficiency allocating gained resources towards
reproduction. Unit-restricted fungi are those that are not able to migrate
between patches of usable resources through vegetative mycelium;
rather, they must colonize new patches through the dispersal of their
spores. The limits on their resource consumption and conversion
efficiencies to reproductive output play their most important role during
resource capture on discontinuous patches, the area of interest in this
study. Discontinuous resources are patches that are not renewed with
new, usable, resources, such as feces and a wood stump. Building off of
John Paul Schmit's work in 1999 titled "Resource consumption and
competition by unit restricted fungal decomposers of patchy
substrates", we used the fungi Coprinus cinereus and Coprinus
congregatus to test how competition interactions between individuals
changes across increasing genetic similarities.
MethodsMethods
Haploid Crosses:
ATCC 38627 x 46814 – Sid
ATCC 66012 x 36519 – Bolt
ATCC 48614 x 66014 – Linda
ATCC 46972 – Congregatus
Alien – Two different species in competition
Stranger – Same species
Self – Same species, inoculates from the same individual
Kin – Same species, "Siblings", dikaryon propagates from
spores of one individual grown and put in competition
Treatments:
bbfruitingfruiting odyody
Figure 1. Average linear growth per individual. Cinereus individuals (Sid, Bolt) and congregatus over
their growth periods (measurements taken in mm approximately 24 hours apart). The colored lines are
linear trend lines of the data collected from each individual.
Line of best fit for Congregatus: y = 5.9064x + 3.58, R² = 0.9968
Line of best fit for Sid: y = 9.8821x + 1.7571, R² = 0.9913; for Bolt: y = 7.6714x + 1.4571, R² = 0.9983
0
20
40
60
80
100
120
Day 1 Day 3 Day 5 Day 7 Day 9 Day 11
Growth(mm)
Time
Avg Linear Growth
Cong
Sid
Bolt
Figure 2. Average linear growth rate per individual. Cinereus individuals (Sid, Bolt) and congregatus over
their growth periods (measurements taken in mm approximately 24 hours apart). The colored lines are
linear trend lines of the data collected from each individual.
Line of best fit for Congregatus: y = -0.0136x + 0.3345
Line of best fit for Sid: y = -0.0286x + 0.5357; for Bolt: y = -0.0018x + 0.3329
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Day 1 Day 3 Day 5 Day 7 Day 9 Day 11
Growth(mm)
Time
Avg Linear Rate
Cong
Sid
Bolt
Figure 3. Average area growth per individual. Measurements for each individual noted approximately
24 hours apart. The colored lines are linear trend lines of the data collected from each individual.
Line of best fit for Congregatus: y = 52.669x - 30.133
Line of best fit for Sid: y = 92.436x - 3.5143; for Bolt: y = 76.159x - 39.481
0
200
400
600
800
1000
1200
Day 1 Day 3 Day 5 Day 7 Day 9 Day 11
Growth(mm)
Time
Avg Area Growth
Cong
Sid
Bolt
Linear (Cong)
Linear (Sid)
Linear (Bolt)
Figure 4. Average area coverage rate per individual. Measurements for each individual noted
approximately 24 hours apart. The colored lines are linear trend lines of the data collected from each
individual.
Line of best fit for Congregatus: y = 0.0198x + 1.9211
Line of best fit for Sid: y = 0.3007x + 2.21; for Bolt: y = 0.15x + 1.9314
0
1
2
3
4
5
6
7
Day 1 Day 3 Day 5 Day 7 Day 9 Day 11
Growth(mm)
Time
Avg Area Rate
Cong
Sid
Bolt
Linear (Cong)
Linear (Sid)
Linear (Bolt)
Figure 5. Stipe biomass of individuals that produced fruiting bodies.
5 stipes
9 stipes 8 stipes
1 stipe
2 stipes
0
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
1 3 7 8 2
Weight(g)
Plate
Stipe Biomass
----------------------------- Congregatus ----------------------------- Bolt
ResultsResultsCoprinus cinereus propagates covered the entire plate within 6-7 days while Coprinus congregatus took at least
10. Cinereus propagates also tended to have heavier fruiting bodies than congregatus, even though it has
already been established that congregatus has a higher efficiency converting resources to reproductive output
than cinereus (this observation was made, however, during the preparation of the experiment, no fruiting bodies
were produced by all but one of the cinereus propagates in the control). During the control phase congregatus
always grew at least 5 fruiting bodies, this statistic cannot be compared with cinereus because of a lack of
samples; it does however suggest the higher conversion efficiency of congregatus. Figures 1 and 2 both display
the amount of linear growth and area covered by the fungus over time; while there was steady growth between
intervals, there was prominent fluctuation between the rate at which these gains were made (Figures 3 and 4).
In figure 3, there is a decline in growth rate as the individual reaches the opposite edge of the plate while in
figure 4 the line of best fit gives us ambiguous data. Although area growth rate appears contingent upon linear
growth, it does not provide any additional data. Figure 5 displays stipe dry weight for every individual that
produced fruiting bodies. Congregatus, despite its slow growth rate, produced considerably more fruiting bodies
than the cinereus individuals, the single bolt inoculate produced a few fruiting bodies.
Control
We had each species grow over a span
of two-weeks. We noted when the
entire plate was taken over and when
the fungi started producing fruiting
bodies. At the end of the growing period
the stipes were removed and
dehydrated to measure individual stipe
biomass, a measure used to calculate
reproductive output (Schmit 1999).
Image J was used to find area of growth
and linear growth (which wasmarked
every day data was collected)
Methods
ConclusionConclusionUnfortunately we were not able to carry out the primary experiment but we did gain valuable information and worked out
necessary techniques. Linear growth data provides more useful information than the area of growth, i.e. linear growth gives
us insight into how mycelium of unit-restricted fungi interacts with the amount of resources and space left on a patchy
substrate whereas the area of growth data remained ambiguous. The fact that congregatus individuals were able to produce
fruiting bodies tells us that a fast growth rate is traded for a higher conversion efficiency, evident in figure 5 where the majority
of fruiting bodies were produced by Congregatus. An error in agar creation, most likely a missing ingredient, could explain
why no Sid inoculates were able to reproduce.
In future experiments, we will have 4 treatments. In these experiments we will test how relatedness between individuals
affects competition, both intraspecifically and interspecifically. We will also introduce a sibling control groups. In this group we
will measure the amount of growth a dikaryon propagate from spores of one individual. Additionally, there will be a new diploid
cross that can be used as a substitute in case either of the previous cinereus plates fails to produce any usable data.
Reproductive output will be measured using the stipe biomass in each treatment. Competition treatments will be conducted
using 5 mm plugs of each individual 10 mm apart from each other, in order to facilitate competitive interactions.
AcknowledgmentsAcknowledgments
I would like to thank Dr. Gina Wesley for choosing me to be a
part of this course and for her guidance in my endeavor. I
would also like to thank Dr. Michael Chase, Dr. Ishrat
Rahman, and Chris Standing for their input research
experience and the rest of those in the Biology department
who critiqued my work during the poster session.
ReferencesReferences
Schmit, J.P. 1999. Resource consumption and competition by
unit-restricted fungal decomposers of patchy substrates. Oikos
87: 509-519.
Coprinus cinereusCoprinus cinereus