Research project: Clare Vergobbi
For her research project, Clare Vergobbi worked with professor Diana Six to study whitebark pine and pine beetles. Whitebark pine (Pinus alibicaulis) is a highly endangered tree species in North America that is dying off in large numbers due to white pine blister rust and mountain pine beetle outbreaks, as well as the effects of climate change on its habitat. We don't know much about how this massive mortality has altered the genetic diversity of whitebark pine populations. These large die-offs can act as strong selection events, removing individuals with lower fitness. Clare wanted to look at whether survivors of mountain pine beetle outbreaks have different genotypes than those killed, and what effect severe beetle outbreaks have on the genetic diversity of populations.
Clare used Inter-Simple Sequence Repeats (ISSR), a method that detects high levels of genetic polymorphism, to test two hypotheses: 1) surviving trees differ genetically from those that are killed by the beetle, and 2) the outbreak has reduced overall genetic diversity in affected stands. She compared the genetic diversity in two whitebark pine stands — one that has experienced a beetle outbreak with scattered survivors, and one that has not experienced beetle kill. She collected needle samples from both populations and isolated the genetic material from each individual tree. Clare is currently screening primers and performing gel electrophoresis to analyze genetic differences between individuals.
This study will develop a more informed approach to whitebark pine restoration. If Clare can identify trees with drought tolerant, beetle-resistant genotypes, managers can use this information to replant trees with favorable genotypes. Whether she is able to detect markers associated with survivor genotypes or not, she will determine whether beetle outbreaks reduce genetic diversity in this tree. This will aid in the understanding of how this tree will adapt to climate change in the future.