PS 26-64 - Secondary dormancy induction in Switchgrass, Panicum virgatum

Background/Question/Methods

Global climate change will require a diverse array of solutions to address our future energy needs. Switchgrass, Panicum virgatum, has long been sought as a potential answer for future biofuel needs. In order to produce a viable amount of liquid fuels from Panicum, we will have to work towards a better understanding of its ecology to maximize its yield as a crop. Our research aims to work towards a better understanding of local adaption in Panicum grasses as a part of a larger collaboration that researches the divergence in Northern upland and southern lowland switchgrass ecotypes. In the course of this experiment both Southern lowland and Northern upland ecotypes were grown under controlled conditions as well as cold exposure conditions in environmental chambers. The progeny of these plants were then followed in a factorial design, where both the progeny of plants grown under control conditions and under cold exposure had phenotypic and physiological measurements taken and were examined for fitness under cold conditions. At the conclusion of this work, RNA extractions were taken from rhizome tissue and sent for illumine sequencing.

Results/Conclusions

We found that in our control plants, which had not undergone any cold acclimation in previous generations, that Northern upland ecotypes acclimated much better to cold temperatures than Southern lowland ecotypes, which was to be expected. When analyzed, it was found that both Northern upland and Southern lowland ecotypes whose parents had undergone the cold acclimation treatment showed quicker induction of secondary dormancy and higher survival rates. The compared results of the Southern lowland control progeny and cold acclimated progeny are especially promising. Showing that past generations can help to prime ecotypes of Panicum grasses’ responses to environmental conditions that they not encountered and have low fitness to is an important step as we work to better our understanding of local adaptation to gain knowledge of how switchgrass grows under differing climate conditions. Furthermore, this helps us understand the variation within and amongst Panicum grass ecotypes. RNA extractions were taken from progeny plants of each ecotype that were grown in control and cold conditions. Going forward the sequence data from these extractions will help us to elucidate the genetic variation that worked to prime the Southern lowland ecotypes to induce secondary dormancy quicker when exposed to cold conditions.