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2017
Tuesday, April 11th
3:45 PM

Allelopathy in Three Species of Neotropical Ferns in the Cloud Forest of Costa Rica

Mary Brady, Whitman College

Science 100

3:45 PM - 4:00 PM

Despite their tranquil appearances, plants are at war. They are constantly fighting with their neighbors for light, nutrients and space. One of the weapons some plants deploy are allelopathic chemicals. These chemicals interfere with the growth and development of other plants within range. These chemicals have many potential uses, including natural herbicides and pesticides. Allelopathy can also be used for conservation. For instance, revegetation projects can be impacted by using species that slow or even stop the growth of the other plants. My study focuses on three species of tropical understory ferns and looks for evidence of allelopathy by growing seeds in dirt collected from under the ferns, growing seeds watered with leachate made from the fern fronds, and analyzing the plantlet communities growing underneath the ferns in situ. In my presentation I show that all three species reveal varying degrees of allelopathy.

4:00 PM

Impact of Competition on the Growth of Pseudoregneria spicata (Bluebunch Wheatgrass) in a Grassland Ecosystem

Chris Daily, Whitman College

Science 100

4:00 PM - 4:15 PM

Competition plays a significant role in dictating the yearly growth of plants in semi-arid grasslands. Bluebunch wheatgrass (BBWG) is a common perennial bunchgrass native to the grasslands of eastern Washington, where the invasive Eurasian annual cheatgrass is pervasive. To assess the impact of neighboring grasses on BBWG growth, I established 13 experimental plots on both north- and south-facing slopes, which differ in water availability, at the Wallula Gap Biological Station in Walla Walla County. Each plot contained one plant with no competition (all neighboring plants removed), one plant with limited competition (only neighboring annual grasses removed) and one control plant. In June 2014 and 2015, I collected data on the growth of each plant, including number and height of stems and seed production. Comparison of the BBWG plants across treatments and between slopes will help determine how competition under different environmental conditions affects the growth of this important native grass.

4:15 PM

Analysis of Candidate Genes for Gain and Loss of Anthocyanin Pigmentation in Mimulus cupreus

Anne Vonada, Whitman College

Science 100

4:15 PM - 4:30 PM

What genetic mechanisms have allowed life to evolve such great diversity? One answer to this question is gene duplication, which allows new gene copies to take on novel functions. In the monkeyflower genus Mimulus, duplication of an anthocyanin-regulating Myb transcription factor gene has been associated with independent gains of anthocyanin pigmentation in multiple species. My presentation explores which Myb copy is responsible for gain and subsequent loss of anthocyanin pigmentation in Mimulus cupreus. Through transcriptome analysis and PCR, I identified and analyzed candidate Myb copies. One promising candidate was found to have a previously unknown splice variant in the pigmented morph and a large deletion in the unpigmented morph. Future research will include gene silencing and rescue to definitively test the contributions of this duplicated gene to flower color diversity, both within and between species.

4:30 PM

The Living Fossil: A Comparative Analysis

Sammi Clute, Whitman College

Science 100

4:30 PM - 4:45 PM

Many extant taxa that have undergone long periods of evolutionary stasis have been classified as "living fossils" to indicate their similarity to fossil specimens. However, the term is inherently relative; claims of living fossils independent of their relation to the rest of the taxon tell us nothing about the nominal or pronounced uniqueness of these slow evolutionary rates. In my study, I compared fossil data to the equivalent modern data from a wide range of taxa to test the hypotheses that the putative living fossils would have more living fossil characteristics compared to their close relatives. Study results provide insight into the scientific relevance of calling something a living fossil; demonstrate the veracity of different criteria attributed to living fossils; and show the feasibility of continuing the investigation into the meaning of this scientific term.

4:45 PM

Encountering Resistance: Investigating Immunity of Lodgepole Pine (Pinus contorta) Against Attack by Mountain Pine Beetle (Dendroctonus ponderosae)

Mitchell Cutter, Whitman College

Science 100

4:45 PM - 5:00 PM

Mountain Pine Beetle (Dendroctonus ponderosae) has decimated large swathes of coniferous forest in Western North America in recent years. Correlated with rising temperatures and increased drought-like conditions, the range of these beetles has expanded swiftly into northern latitudes and high elevations, far beyond the historic range of the species. High-elevation trees, not adapted to beetle attack, are killed at even greater rates (90-95 percent). My presentation investigates a small population of Lodgepole pine (Pinus contorta) which was subject to an infestation of Mountain Pine Beetle but not attacked. Using genetic markers, I analyzed the genetic diversity of these “survivor” trees in comparison to the general population of the area to find evidence of a heritable pine beetle resistance trait in these survivors. This research may lead to more in-depth study on the gene(s) responsible for this trait and potential future use of this resistance in protecting our forests.