Check us out! ARTS is now in the Sciences. 

     We (Bob and Diane Peabody) have worked with more than 40 students on various aspects of the life cycle of the honey mushroom fungus, Armillaria gallica. Our most recent publication is in Mycological Research 107(4):408-412.(2003) with Matthew Towle '02, Liz Johnson '03, and Maura Tyrrell.. 

     You are invited to visit us in 023 of the Science Building to see who is in ARTS and what we are doing…

[For the pictures below, click on the thumbnail to enlarge it, then click the browser back button to return.]

This semester (spring, 2005) Heather Bickford '06 and Greg Saia '05 are studying competition between Armillaria gallica and Armillaria mellea as they grow on malt extract agar and on a defined medium, glucose asparagine.

(Heather Bickford)

In addition to the ecology and competition research on Armillaria gallica and Armillaria mellea, Professor Maura Tyrrell is studying hyphal branching patterns in these species.

Professor Jane Deluca has been developing a protocol for sequencing anonymous regions of DNA in Armillaria gallica single spore isolates. She plans to extend this research to vegetative cell lines of the rhizomorph and soil mycelium to see if the sequences of these regions can be used to distinguish among cell lines.

In the fall of 2004, Directed Study students, Paul Deasey '05, Jeff Wnuk '05, Rafe Marchigiani '05, and Pat Canny '05 studied competition between Armillaria gallica and Armillaria mellea as they grew on red oak and white pine wood and bark extracts.

(left to right: Rafe Marchigiani, Paul Deasey, Pat Canny, Jeff Wnuk)

Last summer (2004) we worked with Maura Tyrrell and four S.U.R.E. (Stonehill Undergraduate Research Experience) students, Elisha Allan'06, Heather Bickford '06, Amy Curdie '06, and Robert Doiron '06 and compared phenotypic plasticity of Armillaria gallica and Armillaria mellea growing on bark and wood extracts of resistant and susceptible host tree species. In November they presented a poster on their results at the 3rd Annual Southeastern Massachusetts Undergraduate Environmental Research Symposium at Bridgewater State College.

(left to right: Heather Bickford, Rob Doiron, Amy Curdie)

In the spring of 2004, we worked with Maura Tyrrell, Megan Campbell '04, Deanna Filosa '04, and Paul Deasey '05 on the host range of Armillaria and presented the results in the poster session at the 62nd Eastern New England Biology Conference at Eastern Nazarene College. Kevin Semelrath '04 and Courtney Sherlock '04 looked for additional molecular markers in Armillaria and gave an oral presentation of the results at the 62nd Eastern New England Biology Conference at Eastern Nazarene College.

(left to right: Deanna Filosa, Megan Campbell, Paul Deasey)

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   (left to right: Kevin Semelrath, Courtney Sherlock)

In the spring of 2003, Directed Study and Ecology students, Brittany Bates '03, Megan Campbell '04, Deanna Filosa '04, and Liz Johnson '03, presented results of their work on molecular markers of Armillaria soil mycelial cell lines and on phenotypic plasticity of these cell lines grown on media prepared from red oak bark and wood extracts at the 61st Eastern New England Biology Conference at Emmanuel College.

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     (left to right: Megan Campbell, Deanna Filosa)

      (left to right: Brittany Bates, Liz Johnson)

In the  summer of 2002, we worked with Maura Tyrrell and three S.U.R.E. students, Emily Edenburn-MacQueen '03, Richard Howdy '03, and Kevin Semelrath '04, on phenotypic plasticity of four cell types (spore, stipe, soil mycelium, and rhizomorph) grown on media of four different water potentials. The students presented their findings at the 1st Annual Southeastern Massachusetts Undergraduate Environmental Research Symposium at Bridgewater State College and at the 61st Eastern New England Biology Conference at Emmanuel College. The results of this research have now been submitted to the journal Mycologia.

(left to right: Kevin Semelrath, Richard Howdy, Emily Edenburn-MacQueen)

During the summer of 2002, Professor Craig Almeida; Chris Levasseur '03, a S.U.R.E. student; and John Silva, a Project S.E.E.D.student (Summer Educational Experience for academically gifted high school students) used Armillaria rhizomorph cell lines  to begin development of  an assay for activity of the enzyme, cellulase.  Characterization of cellulase in individual cell lines was thought to be a  phenotype that might be useful in distinguishing  among cell lines.

During the spring 2002 semester the ARTS team included Matt Towle '02, Liz Johnson '03, and Sam Celia '02. Our goal was to determine (1) how much information would be lost if two rather than eleven replicates of each culture were tested for growth rate and phenotypic plasticity, and (2) whether the same set of plates could be used to obtain quantitative estimates of among-cell differences in branching patterns (hyphal growth units). Although estimates provided by our new method were somewhat less reliable, they appear to be useful as a method of screening large numbers of cells in preliminary studies. Hyphal growth units appear to be useful for quantifying differences in branching patterns in different cells. Matt, Liz and Sam presented a paper at the 60th Eastern New England Biological Conference at Emmanuel College in April. At the same meeting, Jeff Kenyon '02 presented a poster summarizing his Ecology project on phenotypic plasticity of spores grown on media of different water potentials.

((left to right: Bob Peabody, Matt Towle, Liz Johnson, Sam Celia)

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     During the fall of 2001, ARTS includes Professor Roger Denome, Jacqueline Bixby, Pam Podell, Shannon Sheridan, and Andrea Lafont. They looked for SSCP's (single stranded conformational polymorphisms) in rhizomorph cells of Armillaria gallica using the method of Hodnett and Anderson (2000).

          (left to right: Jacqueline Bixby, Pam Podell, Professor Denome, Shannon Sheridan, Andrea Lafont)

Summer (2001) ARTS included Maura Tyrrell, Liz Johnson, '03, and Matt Towle, '02, who worked with us on the biological significance of genetic mosaicism in Armillaria gallica. The research included growth studies that distinguished among cells isolated from A. gallica mushrooms collected in Bridgewater, MA and Raynham, MA during the falls of 1999 and 2000. We tested hypotheses that cells isolated from single mushrooms possess: (1) among-cell genetic variation for rates of hyphal extension, (2) differing responses to environmental variables such as pH and temperature, (3) among-cell genetic variation for these differential responses to environmental variables.

                (left to right: Bob Peabody,Maura Tyrrell, Diane Peabody, Liz Johnson, Matt Towle)

The design of our experiments allowed us to estimate "heritability," the proportion of total trait variation caused by genetic differences among individuals. We were also able to predict the level of evolutionary response to natural selection of the two populations we studied. 

During the spring, 2001 semester Lisa Herman, '01, Karl Stasko, '01, and Ken Sicard, '01 worked on different aspects of the life cycle of Armillaria gallica. These students presented papers at the Eastern New England Biological Conference (ENEBC) at St. Anselm College in April:

  SICARD, KENNETH, LISA HERMAN, and KARL STASKO. 2001. Genetic variation for hyphal extension rate and phenotypic plasticity in spores of the honey mushroom (Armillaria gallica).

  HERMAN, LISA, KARL STASKO, and KENNETH SICARD. 2001. Possible genetic mosaicism in a vegetative stage of the honey mushroom (Armillaria gallica).

  STASKO, KARL, KENNETH SICARD, and LISA HERMAN. 2001. Competitive interactions among spores of the honey mushroom (Armillaria gallica).

                          (left to right: Lisa Herman, Karl Stasko, Ken Sicard)

During the spring, 2001 semester, Maura Tyrrell and one of her ecology students, Katie McAfee, '02, joined ARTS. They presented a poster on their work at ENEBC in April:

  McAFEE, K. 2001. Genetic variation for hyphal extension rate and phenotypic plasticity in spores of the honey mushroom (Armillaria gallica) grown on media with extracts from host tree species.

ARTS in the past
     The following former Stonehill College students (in alphabetical order) have worked with us on Armillaria gallica and contributed to our understanding of this fungus and how it functions in nature:

     Maura Tyrrell and her ecology and botany students, Sharon DiRocco, Keith A. Salvatori, Robert Toriello, Joseph Devine, Colleen MacMahon, and Ken Sicard,  studied growth responses of single spore isolates of A. gallica in various environmental conditions. Ann-Marie Segall and George T. Mattei, Jr. both completed directed studies on Armillaria with Maura which they reported at the Eastern New England Biology Conference.
 
ART at Bridgewater

     During the fall, 2001 semester Professor Frank Gorga of the Bridgewater State College Chemistry Department, and his directed study students, Amy Higgenbottom, '02, and Joseph Worrall, '02, studied the enzymes, cellulase and ligninase, produced by isolates of A. gallica.
 

              (left to right: Professor Frank Gorga, Amy Higginbottom and Joseph Worrall)

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     Diane Peabody was a faculty member in the Biology Department at Bridgewater State College for 21 years. She and Bob want to recognize and extend their appreciation to the following former Bridgewater State College students who contributed to a better understanding of the life cycle of Armillaria gallica: