| Abstract Detail
Speciation Mechanisms in Plants Lowry, David [1]. The genetic and physiological basis of ecological reproductive isolation between coastal perennial and inland annual ecotypes of Mimulus guttatus. Speciation in plants often involves the evolution of ecological reproductive isolating barriers. While extrinsic ecological reproductive isolating barriers generally are stronger than intrinsic reproductive isolating barriers, very little is known about the genetic and physiological mechanisms underlying those ecological isolating barriers. Coastal perennial and inland annual ecotypes of the yellow monkeyflower (Mimulus guttatus) represent an ideal system for understanding the mechanisms underlying ecological reproductive isolation. The inland annual ecotype has evolved a rapid life-history strategy to escape from the summer drought of western North America through the primary allocation of resources to reproduction. In contrast, coastal perennial plants invest heavily in vegetative growth, defense against herbivores, and tolerance to oceanic salt spray. These divergent adaptations between the coastal and inland ecotypes contribute to strong temporal and ecogeographic reproductive isolation. My group is currently working to uncover the genetic and physiological basis of these reproductive isolating barriers. A large chromosomal inversion polymorphism is the largest-effect locus responsible for adaptive divergence in resource allocation between the ecotypes. We hypothesize that this inversion and another key locus interact to shifts allocation of resources through changes in the gibberellin hormone pathway. To test this hypothesis, we are developing CRISPR-Cas9 knock-out lines of candidate gibberellin genes that we hypothesize are key to adaptation and reproductive isolation in this system. In addition, we are working to understand the genetic and physiological mechanisms of differential salt spray adaptations to understand how the inland annual ecotype is ecogeographically excluded from coastal habitats. Overall, we now have a clear understanding of the ecological factors (drought, herbivory, and salt spray) that are responsible for temporal and ecogeographic isolation in this system and have made major progress identifying the underlying mechanisms responsible for the evolution of these barriers.
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1 - Michigan State University, Plant Biology, 612 Wilson Road Rm. 166, East Lansing, MI, 48824, United States
Keywords:
local adaptation
Speciation
Reproductive Isolation
Trade-off
monkeyflower.
Presentation Type: Colloquium Presentations
Session: C09, Speciation Mechanisms in Plants
Location: /
Date: Thursday, July 22nd, 2021
Time: 3:15 PM(EDT)
Number: C09007
Abstract ID:81
Candidate for Awards:None |
