Presentation on theme: "Undergraduate Researcher: Denise Baumann Mentor: Dr. Sujaya Rao"— Presentation transcript:
1A Multitrophic Interaction between a Fly, a Fungus and Orchardgrass in the Willamette Valley Undergraduate Researcher: Denise BaumannMentor: Dr. Sujaya RaoOregon State UniversitySummer 2003
2Orchardgrass in the Willamette Valley Dactylis glomerataApprox. 20,000 acres in the Willamettte ValleySeed CropForage Crop
3Structure of Grass Seed Head Blade (leaf) Tillers Seed Stalk Single grass plantSeed StalkTillersBlade (leaf)
4Endophyte Association Fungal StromaTillersSeed StalkEndophytic FungiSingle grass plant
5- - + Sexual Development of the Fungus (Egg Hatch) Spermatial Transfer (Egg Deposition)+Overwintering &New growth in Spring(Adult Emergence)(Larval Feeding)Harvest(Pupae Formation)
6Choke in orchardgrass (Epichloe typhina) Fungal StomaUnfertilizedFertilized Fungus
7Past Research Bultman and White (midwest) Trials carried out in the wild (isolated grass plants)0-7 larvae per fungal stroma63.8 % of stromata collected had 1 larva only and less than 6% had >3 larvae per stromaStomata with mesh bag had NO perithecia; uncovered stromata had 86.6 % peritheciaFly is necessary for fungal fertilization
8HypothesisIn this fly-fungal interaction in orchardgrass in the Willamette Valley, the fly is not the sole factor for fungal fertilization.
9Objective OneTo determine whether this fly-fungal interaction is mutualistic.Two treatmentsFly physically excluded, spore allowedControl (no exclusion)
11Research Plot on Peoria Rd. Objective OneResearch Plot on Peoria Rd.
12Results Treatment % Fertilization Exclusion (Fly Only) 56% ns No Exclusion69% nsns = no significant differenceConclusion:The fly is not necessary for fungal fertilization in agrass field setting here in the Willamette Valley.
13Objective TwoSurveying orchardgrass in the Willamette Valley to determine the presence of the fly.
14Orchardgrass Sites Corvallis Benton Co. Linn Co. Lane Co. SR HP LR CH WDADKRIBPRNDRR3RR2RR1
16Results 0-10 larvae per fungal stroma 49.2 % of stromata collected had 1 larva/stroma and 15 % had >3 larva/stromaWhen 10 larvae were present, >90% of the fertilized stroma was consumed100 % of stromata fertilized irrespective of larval presence
17Results continued… % Perithecial development at 3 sites SR = 94% (Average of .62 larva/stroma)CH = 97% (no fly found at this site)RR1 = 95.7% (Average of 4.16 larva/stroma)
18In Comparison… My Research Past Research Stated that the fly was obligatory for fungal fertilization63.8% of stromata collected had 1 larva only and less than 6% had >3 larvae per stromaWithout presence of the fly 0% fungal stroma developed peritheciaMy ResearchShows that there may be other factors besides the fly fertilizing the fungus here in the Valley49.2% of stromata collected had 1 larva/stroma and 15% had >3 larva/stroma100% of fungal stroma developed perithecia irrespective of fly presence
19Final SummationIt appears the fly benefits from this interaction in the Willamette Valley; however it is unclear whether there is a positive or negative effect on the fungus.
20Future Research Preference Studies Isolation trials Fungal host preferences by the flyIsolation trialsHow does fertilization occur?Other factors of fungal fertilizationWind, other insects, etc.?
21Acknowledgements Howard Hughes Medical Institute (HHMI) Undergraduate Research Innovation, Scholarship, Creativity (URISC)Sujaya Rao, Jon Umble, Devorah Shamah, Bill Pfender, Steve Alderman, Mark Mellbye, Glenn Fisher, Lynn RoyceOrchardgrass Growers, especially James VanLeeuwen